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Friday, May 20, 2011

Study Sees Link Between Psoriasis, Obesity in Kids

HealthDay News

Friday, May 20, 2011

FRIDAY, May 20 (HealthDay News) -- The prevalence of psoriasis -- a chronic, inflammatory disease of the skin -- is significantly higher among overweight and obese kids, researchers have found.

The Kaiser Permanente study, published online in the Journal of Pediatrics, also found that teens with psoriasis (regardless of their body weight) have higher cholesterol levels, putting them at greater risk for heart disease.

"This study suggests a link between obesity and psoriasis in children," the study's lead author Corinna Koebnick, research scientist at the Kaiser Permanente Southern California's Department of Research & Evaluation, said in a Kaiser Permanente news release.

"But our study findings also suggest that the higher heart disease risk for patients with psoriasis starts in childhood in the form of higher cholesterol levels. We may need to monitor youth with psoriasis more closely for cardiovascular risk factors, especially if they are obese," Koebnick added.

Using electronic health records to study 710,949 racially and ethnically diverse children, the investigators found obese children were almost 40 percent more likely to have psoriasis than normal weight children. At even greater risk, extremely obese children were nearly 80 percent more likely to have psoriasis than normal weight children. Moreover, it was four times more likely for psoriasis to be severe or more widespread in obese youth than in normal weight children.

The study also revealed that, compared with kids without psoriasis, teens with the skin condition had 4 to 16 percent higher cholesterol levels and liver enzymes, regardless of their weight.

Psoriasis, often viewed merely as a burdensome skin condition, may put children at risk for metabolic disease (such as diabetes, metabolic syndrome, and heart disease), as seen in adults, the study authors pointed out.

"It has been well described that adults with psoriasis have increased cardiovascular risk factors, but we have now examined these issues in children," the study's senior author, Dr. Jashin J. Wu, director of clinical research and the associate residency program, and director for the department of dermatology at Kaiser Permanente Los Angeles Medical Center, said in the news release.

"As we follow these patients over 30 to 40 years, we will be able to determine if these increased cardiovascular risk factors in turn increase the risk for major adverse cardiac events," said Wu.

The researchers acknowledged that the study had limitations due to its cross-sectional design, where both body weight and information on psoriasis were assessed at the same time, and stated that these issues would be addressed in future studies.

More information

The American Academy of Pediatrics provides details on childhood obesity.

Gluten not linked to babies' risk of diabetes: study

By Adam Marcus

Reuters Health

Friday, May 20, 2011

NEW YORK (Reuters Health) For babies at higher risk of childhood diabetes because of family history or genes, a gluten-free diet in the first year of life does not lower the chances of developing the disease, German researchers report.

The findings undercut previous studies, including work from the same scientists, suggesting that babies exposed to gluten as part of their early diet might be more likely to develop type 1 diabetes later in childhood.

Although the new study included only 150 children, Dorothy Becker, director of the diabetes program at Children's Hospital of Pittsburgh, told Reuters Health the results are reasonably clear.

"It doesn't mean that it if you did a huge study there wouldn't be an effect (of gluten)," said Becker, who was not involved in the study. "But it makes it unlikely."

Gluten is the protein in wheat and other grains that makes dough elastic and gives bread its chewiness. Roughly 1 percent of people in the United States have a condition called celiac disease, in which immune reactions to gluten damage the intestines.

Each year about 20 kids per 100,000 under the age of 10 in the U.S. are diagnosed with type 1 diabetes, according to the National Institutes of Health. In contrast with type 2 diabetes, which is usually a disease of adults and associated with old age or obesity, type 1 diabetes typically strikes children.

Many of them likely inherited a genetic predisposition to the disease from their parents. Yet genes alone don't fully explain why people develop the condition. Other factors, such as environmental exposures, are thought to be necessary to trigger it.

In the latest study, the researchers followed 150 babies with at least one parent or sibling who had been diagnosed with type 1 diabetes -- marked by the death of islet cells in the pancreas that secrete the hormone insulin. The body requires insulin to convert dietary sugars into energy.

Half of the children were exposed to gluten in their diet for the first time at the age of six months. For the rest, exposure to the protein was delayed until after their first birthday.

The different diets appeared to have no impact on the babies' ability to grow or gain weight.

By age 3, three children exposed to gluten early had developed type 1 diabetes, compared to four in the late-exposure group. Signs that the children had developed immune reactions to their own islet cells - a possible precursor to diabetes, especially in those with a genetic predisposition for the disorder - appeared in 11 children given gluten at six months of age, compared to 13 who first ate gluten when they were 12 months old.

Some research has suggested that delaying exposure to gluten can increase the risk of developing celiac disease. However, the German scientists said they found no evidence for such a link.

Roughly 30 percent of parents said they did not strictly follow the diet plan. Still, the researchers said, the results of the study show that although delaying the introduction of gluten into a baby's diet causes no harm, it doesn't appear to reduce the risk of diabetes or immune-related early-indicators of insulin problems.

The researchers did not respond to requests for comment on their study, which appeared online last month in the journal Diabetes Care.

Research into other potential food triggers for type 1 diabetes is ongoing. Last November, researchers in Finland reported that babies with a genetic predisposition for type 1 diabetes who were fed an infant formula called Nutramigen were about half as likely as those given conventional cows' milk formulas to show signs of islet cell autoimmunity later in childhood. The milk proteins in Nutramigen (sold as Enfamil by Mead Johnson & Co.) are altered in a way that makes them more tolerable to the immune system.

Becker is helping to lead a large international trial funded by the National Institutes of Health to further explore the Finish findings. The results of that study, which includes nearly 2,200 babies, are expected in 2017, she said.

Source: http://bit.ly/hz

Gutn Diabetes Care, online April 22, 2011.

Psoriasis, High Blood Pressure May Be Linked

HealthDay News

Friday, May 20, 2011

FRIDAY, May 20 (HealthDay News) -- People who have psoriasis and hypertension are more likely to have more severe high blood pressure, requiring more medications to control it, a new study suggests.

About 4 percent of the U.S. population has psoriasis, which causes itchy, thickened, dry, red patches on the skin.

Researchers from the University of California, Davis Health System examined 835 patients who had psoriasis and hypertension. Their cases were compared with more than 2,400 people who had hypertension but not psoriasis.

The patients with psoriasis were more likely to need the highest level of blood pressure treatment, which relies on a central-acting agent (also known as adrenergic inhibitors) that's used in people whose high blood pressure can't be controlled with conventional medications.

Hypertensive patients with psoriasis were also nearly 20 times more likely to be on four drugs or on a central-acting agent than hypertensive patients without psoriasis.

The study is published online in PLoS One.

The study's authors noted the findings were significant even after other risk factors associated with hypertension, including diabetes, smoking and high cholesterol, were taken into account. The researchers also pointed out it is unlikely that drugs used to treat psoriasis are responsible for the increased severity of hypertension.

"Our study makes a strong case that psoriasis is not just a skin-deep disease," said lead study author Dr. April W. Armstrong, UC Davis assistant clinical professor of dermatology, in a university news release. "We are beginning to find that psoriasis may represent a window into detecting cardiovascular conditions, including hypertension."

Armstrong added that the findings may alert physicians who treat hypertension, a risk factor for heart disease and stroke. "Hypertensive patients who also have psoriasis are likely to need closer monitoring and a more aggressive drug regimen to achieve adequate blood-pressure control," she said.

Over the past four decades, researchers have developed several theories to explain the link between psoriasis and hypertension, including:

People with psoriasis may be more likely to develop constricted blood vessels, which increases blood pressure.

Patients with psoriasis have elevated levels of a protein produced by skin cells (endothelin I), which constricts blood vessels and increases blood pressure.

As an inflammatory disease, psoriasis can result in damage to blood vessels and the heart.

"Our understanding of psoriasis as a systemic disease is rapidly evolving," concluded Armstrong. "A better appreciation of the other conditions that tend to accompany psoriasis could potentially drive our therapy of the disease in the future."

While the new study found an association between psoriasis and high blood pressure, it did not demonstrate a cause-and-effect.

More information

The U.S. National Institutes of Health offers more detailed information on psoriasis.

High Iron, Copper Levels Block Brain-Cell DNA Repair

ScienceDaily

Friday, May 20, 2011

ScienceDaily (May 20, 2011) No one knows the cause of most cases of Alzheimer's, Parkinson's and other neurodegenerative disorders. But researchers have found that certain factors are consistently associated with these debilitating conditions. One is DNA damage by reactive oxygen species, highly destructive molecules usually formed as a byproduct of cellular respiration. Another is the presence of excessive levels of copper and iron in regions of the brain associated with the particular disorder.

University of Texas Medical Branch at Galveston researchers have discovered how these two pieces of the neurodegenerative disease puzzle fit together, a connection they describe in a review article in the current Journal of Alzheimer's Disease. A high level of copper or iron, they say, can function as a "double whammy" in the brain by both helping generate large numbers of the DNA-attacking reactive oxygen species and interfering with the machinery of DNA repair that prevents the deleterious consequences of genome damage.

"It's been suggested that an imbalance of DNA damage and repair produces a buildup of unrepaired genetic damage that can initiate neurodegenerative pathology," said postdoctoral fellow Muralidhar Hegde, lead author of the paper. "We don't yet know enough about all the biochemical mechanisms involved, but we have found multiple toxic mechanisms linking elevated iron and copper levels in the brain and extensive DNA damage -- pathological features associated with most neurodegenerative disorders."

Humans ordinarily have small amounts of iron and copper in their bodies -- in fact, the elements are essential to health. But some people's tissues contain much larger quantities of iron or copper, which overwhelm the proteins that normally bind the metals and sequester them for safe storage. The result: so-called "free" iron or copper ions, circulating in the blood and able to initiate chemical reactions that produce reactive oxygen species.

"Reactive oxygen species cause the majority of the brain cell DNA damage that we see in Alzheimer's and Parkinson's disease, as well as most other neurodegenerative disorders," Hegde said. "It's bad enough if this damage occurs on one strand of the DNA double helix, but if both strands are damaged at locations close to each other you could have a double-strand break, which would be fatal to the cell."

Normally, special DNA repair enzymes would quickly mend the injury, restoring the genome's integrity. But experiments conducted by Hegde and his colleagues showed that iron and copper significantly interfere with the activity of two DNA repair enzymes, known as NEIL1 and NEIL2.

"Our results show that by inhibiting NEIL1 and NEIL2, iron and copper play an important role in the accumulation of DNA damage in neurodegenerative diseases," Hegde said.

The researchers got a surprise when they tested substances that bond to iron and copper and could protect NEIL1 from the metals. One of the strongest protective agents was the common South Asian spice curcumin, which also has been shown to have other beneficial health effects.

"The results from curcumin were quite beautiful, actually," Hegde said. "It was very effective in maintaining NEIL activity in cells exposed to both copper and iron."

Other authors of the Journal of Alzheimer's Disease paper include research associate Pavana Hegde; K.S. Rao, director of the Institute for Scientific Research and High Technology Services in Panama; and UTMB Professor Sankar Mitra. The United States Public Health Service and the American Parkinson's Disease Association supported this research.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

Muralidhar L. Hegde, Pavana M. Hegde, K.S. Jagannatha Rao, Sankar Mitra. Oxidative Genome Damage and Its Repair in Neurodegenerative Diseases: Function of Transition Metals as a Double-Edged Sword. Journal of Alzheimer's Disease, April 2011, Vol 25, Number 1, Pages 183-198

Study Suggests Supplement May Protect Against Preeclampsia

HealthDay News

Friday, May 20, 2011

FRIDAY, May 20 (HealthDay News) -- Though a new study suggests that a dietary supplement could lower the likelihood that high-risk pregnant women will develop preeclampsia, the jury is still out over whether it actually works and a specialist recommends that women not try it yet.

Preeclampsia is a pregnancy complication that can boost blood pressure to abnormally high levels, causing hypertension. It affects about 5 percent of first pregnancies.

"Women die of uncontrolled hypertension through stroke or multi-organ failure," said Dr. David Williams, an obstetrician and consultant in maternal medicine at University College London Hospitals, who co-wrote a commentary accompanying the study, which was published online May 19 in BMJ.

"Comprehensive prenatal care and modern medical practice in developed countries makes maternal mortality from preeclampsia a rare event, but it accounts for 20 percent of maternal mortality in many developing countries," Williams explained.

Scientists suspect that low levels of an amino acid called L-arginine could play a role in the development of the disease, and some have wondered whether antioxidant vitamins could lower the risk of the condition.

For the study, researchers in Mexico assigned high-risk pregnant women to one of three groups: 228 ate food bars containing L-arginine and antioxidant vitamins; 222 ate bars with vitamins only; and 222 ate bars that didn't contain the amino acid or the vitamins, considered the placebo group.

After eating the food bars daily from 20 weeks into their pregnancy through delivery, only 13 percent of the women who ate bars with L-arginine plus antioxidants developed preeclampsia; they also were less likely to give birth prematurely. In the vitamins-only group, 23 percent developed preeclampsia, as did 30 percent of women in the placebo group.

"This relatively simple and low-cost intervention may have value in reducing the risk of preeclampsia and associated preterm birth," the study concluded.

But the authors of the accompanying commentary raise questions about possible harmful effects and suggest there needs to be more research to understand "the numerous inconsistent strands of evidence relating to L-arginine and its possible effects on preeclampsia."

Williams said: "We still do not understand the complex, interacting ways in which preeclampsia develops, and it is likely to be different in different women. More work needs to be done to understand the potential of L-arginine with antioxidant vitamins, and at this stage, we do not recommend that this supplementation should be given to women at risk of preeclampsia."

More information

For more about preeclampsia, visit the U.S. National Library of Medicine.

Exercise Helps Women Fight Smoking Cravings, but Effect Is Short-Lived

ScienceDaily

Friday, May 20, 2011

ScienceDaily (May 20, 2011) For years researchers have found that exercise can curb nicotine cravings, but have struggled to show a practical benefit in trials. Newly published research suggests a reason: the effect is too ephemeral. The next step, funded by a 5-year grant, will be to see how frequently exercise might be needed to have a lasting therapeutic effect.

Dozens of studies on whether moderate exercise can curb the nicotine cravings of women smokers have added up to an apparent contradiction: it seems to work in short-term, well controlled lab experiments, but then fizzles out in treatment trials. A new study may explain why and help researchers devise a practical therapy.

The explanation suggested in the results of research led by David Williams, an assistant professor of community health at Brown University, is that while exercise does help improve the mood of smokers and curtail their cravings, the effect is short-lived.

"What we found is that although there is no chronic effect of exercise on cigarette cravings and affective withdrawal symptoms, there is an acute effect that diminishes over a period of several hours to 1-2 days, but can be renewed with each bout of exercise," said Williams, first author of the study published May 11 in the journal Addictive Behaviors. "One implication for these findings is that exercise may be a useful treatment strategy, but it has to be done frequently enough and consistently enough because the effects that it has diminish over time."

To conduct their pilot study, Williams and colleagues at The Miriam Hospital, the University of Massachusetts at Boston, and St. George University of London signed up 60 female smokers for an 8-week regimen of smoking cessation treatment. They were all given quitting counseling and nicotine patches. Half were assigned to the exercise group, in which they briskly walked on a treadmill at the study center for 50 minutes three times a week. The 30 women in the control group watched 30-minute health and wellness videos three times a week.

For each group the researchers asked them about their mood and cigarette cravings immediately before and after each session. They also asked them again when they reached their next destination after each exercise or wellness session.

The researchers found that, relative to participants in the control group, those who exercised were more likely to experience improved mood and decreased cigarette cravings, but that these effects dissipated by the time of their next exercise session. On one hand, the improvements in affect and cravings are encouraging, Williams said, but clearly it wasn't sustained even over a matter of a few days.

The next step, he said, is to enroll a larger sample of women in a randomized, controlled trial. That work is well underway because in February his pilot research led to a new NIH grant for $2.2 million over 5 years to study the issue in further detail. The study will allow him and his team to provide enrolled women with electronic devices where they can record their cravings and mood more frequently.

Once Williams has a better sense of when the effects of exercise wear off, he'll know how frequent exercise needs to be to sustain its anti-craving benefit.

In addition to Williams, other authors are Shira Dunsiger, Joseph T. Ciccolo and Ernestine Jennings of the Warren Alpert Medical School of Brown University and The Miriam Hospital, Jessica Whiteley of the University of Massachusetts at Boston, and Michael H. Ussher of St. George's University of London, UK.

The National Institutes of Health funded the research.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

David M. Williams, Shira Dunsiger, Jessica A. Whiteley, Michael H. Ussher, Joseph T. Ciccolo, Ernestine G. Jennings. Acute effects of moderate intensity aerobic exercise on affective withdrawal symptoms and cravings among women smokers. Addictive Behaviors, 2011; 36 (8): 894 DOI: 10.1016/j.addbeh.2011.04.001

Sleep Disorder Linked to Heart Rhythm Problems

HealthDay News

Friday, May 20, 2011

FRIDAY, May 20 (HealthDay News) -- People with an implantable cardiac defibrillator and a breathing disorder that occurs during sleep are at greater risk for potentially deadly heart problems during the night, new research suggests.

An implantable cardiac defibrillator (ICD) is a device that monitors heart rhythm and corrects an abnormal heartbeat with an electrical shock. The new study revealed a significant increase in cases of ventricular tachycardia (a dangerous rapid heartbeat) and ventricular fibrillation (a severely abnormal heart rhythm) among patients with ICDs who also were diagnosed with sleep-disordered breathing.

In the study, published in the May issue of the journal HeartRhythm, researchers in Israel analyzed 45 patients with ICDs in an overnight sleep study and followed them over the course of one year.

Twenty-six of the study participants (57.8 percent) had sleep-disordered breathing, and these patients were more likely to receive what the researchers call "appropriate ICD therapy" -- a shock to correct the heart rhythm.

The risk for ventricular arrhythmias was higher between midnight and 6 a.m. among patients with sleep-disordered breathing, the results showed. The researchers concluded that patients with an ICD who experience nighttime arrhythmias should undergo screening for sleep-disordered breathing.

"Currently, there is limited data available with regard to the predictors of fatal arrhythmias in patients with an ICD," study author Dr. Tawfig Zeidan-Shwiri, of Ramban Medical Center in Haifa, Israel, said in a news release from the Heart Rhythm Society.

"Our study sought to find specific clinical data to help improve the safety and quality of life of patients living with an ICD, and the results indicate that the presence of sleep-disordered breathing should be considered in all patients with appropriate ICD therapy," Zeidan-Shwiri added. "However, more studies are needed to assess whether treatment of sleep-disordered breathing reduces the risk of appropriate ICD therapy."

More information

The U.S. National Institutes of Health has more information on sleep-disordered breathing.

Thursday, May 19, 2011

Study finds supplement may help pregnancy problem

Reuters

Thursday, May 19, 2011

LONDON (Reuters) Scientists studying the pregnancy complication pre-eclampsia say a dietary supplement containing an amino acid and antioxidant vitamins given to expectant mothers at high risk could reduce occurrence of the disease.

In a study in the British Medical Journal (BMJ) on Friday, researchers found that pregnant women taking supplements with the amino acid L-arginine plus vitamins were significantly less likely to develop pre-eclampsia compared with those taking just vitamins, or those taking a placebo supplement.

Pre-eclampsia is a serious condition marked by abnormally high blood pressure and high protein levels in the urine. It affects about 5 percent of all first-time pregnancies and is dangerous for both mother and child.

Experts estimate that the cost of treating women with pre-eclampsia is $45 billion a year in the United States, Europe, Asia, Australia and New Zealand. In developing countries, an estimated 75,000 women die of it each year.

If mothers and their babies survive, the women later have a higher risk of high blood pressure, heart disease, stroke and diabetes. The babies are often born prematurely and can suffer complications later in life.

Pre-eclampsia is thought to be linked to a deficiency in L-arginine, an amino acid that helps to maintain a healthy blood flow during pregnancy. Some experts also think that antioxidant vitamins can help protect against the condition.

This study took place at a hospital in Mexico City. Pregnant women at high risk of pre-eclampsia received either daily food bars containing both L-arginine and antioxidant vitamins, bars containing vitamins only, or placebo "dummy" bars containing no L-arginine or vitamins. The supplements began when women were around 20 weeks pregnant and continued until delivery.

The proportion of women developing pre-eclampsia was 30.2 percent in the placebo group, 22.5 percent in the vitamin only group, and 12.7 percent in the L-arginine plus vitamin group.

"This relatively simple and low cost intervention may have value in reducing the risk of pre-eclampsia and associated preterm birth," the researchers, from Mexico and the United States, wrote in their study.

Two British experts commenting on the work in the BMJ said it was an important finding but crucial questions remained.

Before any more trials were started, they said, researchers should seek to establish how L-arginine and vitamins work together, what the potential harmful effects might be, and what the results might be in other populations and places.

(Reporting by Kate Kelland, editing by Paul Casciato)

Wednesday, May 18, 2011

Dairy Consumption Does Not Elevate Heart-Attack Risk, Study Suggests

ScienceDaily

Wednesday, May 18, 2011

ScienceDaily (May 18, 2011) Dairy products can be high in harmful saturated fat but not necessarily in risk to the heart. A newly published analysis of thousands of adults in Costa Rica found that their levels of dairy consumption had nothing to do statistically with their risk of a heart attack.

"Things like milk and cheese are very complex substances," said Stella Aslibekyan, a community health graduate student at Brown University and the lead author of the study, published in advance online May 4 in the journal Nutrition, Metabolism and Cardiovascular Diseases. "We looked at [heart attack risk and] dairy products in their entirety and then looked at separate components of those dairy products, including fats, and it turns out that the results are null. Perhaps the evidence is not there."

Rather than suggesting that the saturated fats in dairy products are harmless, Aslibekyan and co-author Ana Baylin, an adjunct assistant professor of community health at Brown, hypothesize that other nutrients in dairy products are protective against heart disease, for all but perhaps the highest dairy consumption quintile in their study. The potentially beneficial nutrients include calcium, vitamin D, potassium, magnesium and conjugated linoleic acid (CLA).

To conduct the study, Aslibekyan and Baylin analyzed data on 3,630 middle-aged Costa Rican men and women who participated in an epidemiological study between 1994 and 2004 by co-author Hannia Campos of the Harvard School of Public Health.

They split the study population between two equal groups: 1,815 "cases" who had non-fatal heart attacks and 1,815 comparable "controls" who did not. The researchers looked not only at the subjects' self-reported dairy intake, but also at measurements of dairy fat biomarkers, namely 15:0 and 17:0, in their bodies.

What they found is that the dairy intake of people who had heart attacks was not statistically different than the intake of people who did not. After breaking people into quintiles, based on their dairy consumption amount, there was no significant linear relationship between consumption and heart risk, even among the most voracious consumers. The highest consumption quintile consumed an average of 593 grams of dairy foods a day.

When the researchers controlled for such risk factors as smoking, waist-to-hip ratio, alcohol intake, and physical activity, the lack of a statistically significant association between dairy intake and heart attack risk remained. They also tracked and adjusted the data for levels of CLA and calcium and found they may have a protective effect. Protective effects lessened in the highest quintile, however.

Baylin likened the nutritional complexity of dairy products to that of eggs, which were once a source of intense consumer concern because of their cholesterol content, but are now viewed in a more complex way because they, too, have seemingly protective nutrients.

"The message is that it is important to look at the net effect of whole foods and dietary patterns and not only isolated nutrients" Baylin said.

Since conducting the study at Brown, Baylin has been appointed an assistant professor of epidemiology at the University of Michigan School of Public Health. Aslibekyan, who will graduate from Brown May 29 with a PhD, is already employed as a postdoctoral scholar at the University of Alabama at Birmingham.

The National Institutes of Health funded the research with grant HL60692.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

S. Aslibekyan, H. Campos, A. Baylin. Biomarkers of dairy intake and the risk of heart disease. Nutrition, Metabolism and Cardiovascular Diseases, 2011; DOI: 10.1016/j.numecd.2011.02.003

When Pregnant Mom Smokes, Baby's DNA May Change

HealthDay News

Wednesday, May 18, 2011 

WEDNESDAY, May 18 (HealthDay News) -- Women who smoke during pregnancy may be putting their unborn children at increased risk for a DNA change, a new study suggests.

The change, called DNA methylation, can change a gene's usual function. The researchers argue that the altered genes, which can be passed from parent to child, may explain why some children are more likely than others to develop certain diseases, such as childhood asthma.

The study, which was to be presented Wednesday at an American Thoracic Society conference in Denver, analyzed questionnaires completed by the mothers and grandmothers of 173 children that assessed their smoking habits during pregnancy. DNA samples from cheek cells of mothers and children were also collected and evaluated.

The researchers found that DNA methylation of the AXL gene, a gene that plays an important role in many human cancers and immune response, occurred more than twice as often in children whose mothers had smoked while carrying them in the womb.

They noted a stronger association in girls than in boys, and they found no significant tie between a grandmother's smoking and DNA methylation of AXL in either the mother or her child.

"Imprinted genes appear to be particularly susceptible to these exposures since they come from one parent and only a single copy from one chromosome in DNA is active," study author Carrie Breton, an assistant professor of preventive medicine at the University of Southern California said in a American Thoracic Society news release. "Any environmentally induced epigenetic changes will have greater impact on gene expression and function. In utero and early life exposures are likely to be important, given what we know about timing during development when epigenetic marks are established."

Investigating the effects of environmental exposures on epigenetics, or changes in gene function or expression that occur as the result of mechanisms other than changes to the underlying DNA sequence, is a largely unexplored area of research that holds great promise for understanding the biological mechanisms that underlie exposure-disease associations, Breton added.

"We are interested in further characterizing the pattern of epigenetic marks across this gene and whether there is a widespread response to both maternal smoking exposure and air pollution exposure in utero," she said. "We hope to also evaluate timing of effects of exposure during trimester by increasing the number of samples we evaluated in a manner that will let us compare trimester-specific exposures."

Experts note that research presented at meetings should be considered preliminary because it has not been subjected to the rigorous scrutiny given to research published in medical journals.

More information

The U.S. Centers for Disease Control and Prevention has more on smoking and pregnancy.

Peanut-eating blood donors spark allergic reaction

By Gene Emery and Genevra Pittman

Reuters Health

Wednesday, May 18, 2011

NEW YORK (Reuters Health) A Sunday night custom of eating peanuts while watching soccer has led to a discovery: What you eat before you give blood may result in a severe allergic reaction in people who receive that blood.

A report in the May 19 New England Journal of Medicine concludes that a 6-year-old boy who received a transfusion suffered such a reaction because three of the five donors had eaten peanuts the night before their donation.

The researchers said that, for the moment, they are not recommending any changes in blood donation practices.

Yet they also cautioned that similar cases may have occurred and gone unreported.

The child received the transfusion as part of his treatment for acute lymphoblastic leukemia, a blood cancer. He experienced a rash, low blood pressure, swelling, and difficulty breathing, but recovered following resuscitation.

The mother of the boy recalled that he had had a similar reaction after eating peanuts when he was one year old.

At that point, investigators went back and interviewed the five donors.

Coauthor Dr. Joannes Jacobs of the Radboud University Nijmegen Medical Center in Nijmegen, the Netherlands, told Reuters Health that three reported eating several handfuls of peanuts the evening before the donation.

One of the three provided the plasma portion of the transfusion, he said.

Why did the three remember when they had eaten peanuts?

Coauthor Dr. Elisabeth van Pampus said told Reuters Health by email that the transfusion came only four days after the donation.

In addition, said Jacobs, "On Sunday evening in the Netherlands, the big thing is to watch soccer on the couch, and some people consume peanuts," so they recalled what they had been snacking on.

The allergic reaction happened, the researchers said, because the major peanut allergen resists digestion, and it also creates another protein that gets into the blood and stays there for up to 24 hours. The boy had antibodies to both.

Jacobs said the theoretical possibility of this happening was suggested in 2003. "This is the first clinical report of this."

Some cases may "have gone unexplained and unreported," the researchers warned.

"We must analyze when this happens and how often it happens," Jacobs said. "We must create awareness that this phenomenon can take place."

Dr. Dan Waxman, president of America's Blood Centers and chief medical officer at the Indiana Blood Center, agreed that in the United States as well, there is a need for a national system to record how often these types of reactions occur.

He suspects that a peanut allergy-related reaction is extremely rare. What may be more of a worry, and what blood banks are addressing, he said, is the case of a patient who is allergic to penicillin, for example, getting a transfusion from someone who was taking the drug.

"We're really good about donor questionnaires about medication these days, or if someone's taking an antibiotic," Waxman, who was not involved in the new report, told Reuters Health.

"We ask a certain amount of health history (from donors), but in terms of what people might have eaten, we really don't ask."

Source: http://bit.ly/jO1EOz

New England Journal of Medicine, online May 18, 2011.

Selenium Might Help Treat Symptoms in Graves' Eye Disease

By Serena Gordon
HealthDay Reporter

HealthDay News

Wednesday, May 18, 2011

WEDNESDAY, May 18 (HealthDay News) -- The trace mineral selenium improves quality of life and slows the progression of eye problems in people with the autoimmune disorder known as Graves' disease, a new study says.

Italian researchers report that they compared daily selenium use to both a medication called pentoxifylline and a placebo, and found that selenium could benefit people with Graves' disease with eye involvement, without causing side effects.

"Our study demonstrates that patients with mild Graves' orbitopathy, [who are] usually not given any specific treatment, can benefit from a six-month course of selenium selenite [100 micrograms twice daily], both in terms of amelioration of eye manifestations and improvement in quality of life," said study author Dr. Claudio Marcocci, a professor of endocrinology at the University of Pisa, Italy.

Graves' disease is an autoimmune disease that usually affects the thyroid gland, causing hyperthyroidism, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Common symptoms of the disease include nervousness, irritability, weight loss, fatigue, muscle weakness, hand tremors and trouble sleeping, according to the NIDDK.

The disease can also cause the immune system to attack the area around the eyes, causing inflammation in the tissue behind the eye socket. This can cause the eyes to protrude, a common sign of Graves' disease. When the eyes are affected by Graves' disease it's often referred to as Graves' ophthalmopathy or Graves' orbitopathy.

Symptoms of Graves' ophthalmopathy include dry eyes, puffy eyelids, double vision, sensitivity to light, a feeling of eye pain or pressure and difficulty moving the eyes, according to NIDDK. Approximately one out of four people with Graves' disease will develop mild to moderate eye symptoms that usually last for a year or two and then resolve on their own, reports NIDDK. Fewer than 5 percent of people with Graves' develop severe eye symptoms.

There aren't any known effective treatments for Graves' ophthalmopathy, said Dr. Jacob Warman, chief of endocrinology at the Brooklyn Hospital Center in New York City. Lubricant eye drops can help relieve some symptoms, but they don't alter the course of the disease.

Pentoxifylline is an anti-inflammatory medication and selenium acts as an antioxidant. The researchers suspected that both substances had properties that could help prevent some of the damage caused by Graves' eye disease.

The study authors recruited 159 people with mild Graves' orbitopathy, and randomly assigned them to receive two daily doses of either 100 micrograms of selenium, 600 milligrams of pentoxifylline or a placebo.

After six months, the researchers found that selenium treatment, but not pentoxifylline or the placebo, was associated with an improved quality of life. Selenium was also found to slow the progression of Graves' orbitopathy and reduce eye symptoms compared to the placebo and pentoxifylline.

Additionally, the researchers found that the benefits of selenium lasted for at least another six months after the study ended.

There were no adverse effects reported with selenium or placebo use. Several people on pentoxifylline reported nausea, bloating and abdominal discomfort.

Results of the study are published in the May 19 issue of the New England Journal of Medicine.

One caveat noted by Marcocci is that the population in the area where this study was conducted tends to be selenium-deficient. So, in an area where people get sufficient selenium, it's not clear if additional amounts of this trace element would still provide benefit. Selenium is found in plant sources, such as corn, wheat and soybean, according to the U.S. Office of Dietary Supplements. It's also found in some meats, such as chicken, beef and turkey.

Warman pointed out that another limitation of this study is that it's quite small, with only about 50 people in each treatment group.

"There doesn't appear to be a downside to selenium, so it might be worthwhile to try this relatively simple treatment to prevent eye symptoms. But, a larger study should be done," he noted.

Marcocci said he would recommend that people with Graves' orbitopathy try selenium for six months to see if their symptoms improve.

More information

Learn more about Graves' disease from the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.

Simple Fitness Test Could Predict Long-Term Risk for Heart Attack, Stroke in Middle-Aged People

ScienceDaily

Wednesday, May 18, 2011

ScienceDaily (May 18, 2011) If you're middle-aged, the answer could provide a strong predictor of your risk of heart attack or stroke over the next decade or more.

In two separate studies, UT Southwestern Medical Center researchers have found that how fast a middle-age person can run a mile can help predict the risk of dying of heart attack or stroke decades later for men and could be an early indicator of cardiovascular disease for women.

In one recent study in the Journal of the American College of Cardiology, researchers analyzed the heart disease risk of 45-, 55- and 65-year-old men based on their fitness level and traditional risk factors, such as age, systolic blood pressure, diabetes, total cholesterol and smoking habits. The scientists found that low levels of midlife fitness are associated with marked differences in the lifetime risk for cardiovascular disease.

For example, a 55-year-old man who needs 15 minutes to run a mile has a 30 percent lifetime risk of developing heart disease. In contrast, a 55-year-old who can run a mile in eight minutes has a lifetime risk of less than 10 percent.

"Heart disease tends to cluster at older ages, but if you want to prevent it, our research suggests that the prescription for prevention needs to occur earlier -- when a person is in his 40s and 50s," said Dr. Jarett Berry, assistant professor of internal medicine and a corresponding author on both studies.

Researchers in this study found that a higher fitness level lowered the lifetime risk of heart disease even in people with other risk factors.

In a separate study in Circulation, UT Southwestern researchers found that the same treadmill test predicts how likely a person is to die of heart disease or stroke more accurately than assessing the risk using only typical prediction tools such as blood pressure and cholesterol levels.

Heart disease is a leading killer in industrialized nations and the No. 1 killer of women in the U.S. Women younger than 50 are particularly difficult to assess for long-term cardiovascular risk.

"Nearly all women under 50 years of age are at low risk for heart disease," Dr. Berry said. "However, as women get older, their risk increases dramatically. In our study, we found that low levels of fitness were particularly helpful in identifying women at risk for heart disease over the long term."

For decades, scientists have tried to improve their ability to determine which patients are at highest cardiovascular disease risk. Blood-based and imaging techniques have been used to try to improve risk prediction, but fitness has not been examined until now, Dr. Berry said.

For both studies, researchers collected information from thousands of participants who underwent a comprehensive clinical exam and a treadmill exercise test at the Cooper Clinic in Dallas between 1970 and 2006.

In the JACC study, researchers evaluated more than 11,000 men tested before 1990 -- women were excluded because of the low number of participants and cardiovascular death rates -- and found 1,106 who died of heart attack or stroke during the study period. They measured participant fitness levels and traditional risk factors for heart disease. Within each age group, higher levels of fitness were associated with lower levels of traditional risk factors.

For the Circulation study, researchers examined more than 66,000 participants without cardiovascular disease, ages 20 to 90. They were then followed until death or the end of the study period; follow-up lasted up to 36 years. There were 1,621 cardiovascular deaths during the study. The researchers found that by adding fitness to the traditional risk factors, they significantly improved their ability to classify participants' short-term (10 years) and long-term (25 years) risk.

Researchers next will try to extend the JACC investigation parameters to women.

Other UT Southwestern researchers involved in the Circulation study were Dr. Sachin Gupta, a postdoctoral trainee in internal medicine and lead author; Dr. Anand Rohatgi, assistant professor of internal medicine; Colby Ayers, faculty associate in internal medicine; Dr. Amit Khera, assistant professor of internal medicine; Dr. Mark Drazner, professor of internal medicine and medical director of the Heart Failure, Left Ventricular Assist Devices and Cardiac Transplant Program; and Dr. James de Lemos, associate professor of internal medicine. Researchers from the Cooper Clinic in Dallas and Stanford University also participated in the research.

Other UT Southwestern researchers involved in the JACC study were Drs. Susan Lakoski, assistant professor of internal medicine; and Drs. de Lemos, Gupta, Khera and Rohatgi. Researchers from the Cooper Clinic, Stanford and Northwestern universities also participated.

The National Institutes of Health and the American Heart Association funded the

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal References:

  1. Jarett D. Berry, Benjamin Willis, Sachin Gupta, Carolyn E. Barlow, Susan G. Lakoski, Amit Khera, Anand Rohatgi, James A. de Lemos, William Haskell, Donald M. Lloyd-Jones. Lifetime Risks for Cardiovascular Disease Mortality by Cardiorespiratory Fitness Levels Measured at Ages 45, 55, and 65 Years in Men. Journal of the American College of Cardiology, 2011; 57 (15): 1604 DOI: 10.1016/j.jacc.2010.10.056
  2. S. Gupta, A. Rohatgi, C. R. Ayers, B. L. Willis, W. L. Haskell, A. Khera, M. H. Drazner, J. A. de Lemos, J. D. Berry. Cardiorespiratory Fitness and Classification of Risk of Cardiovascular Disease Mortality. Circulation, 2011; 123 (13): 1377 DOI: 10.1161/CIRCULATIONAHA.110.003236

 

Tuesday, May 17, 2011

Could Coffee Lower Men's Risk for Prostate Cancer?

By Steven Reinberg
HealthDay Reporter

HealthDay News

Tuesday, May 17, 2011

TUESDAY, May 17, 2011 (HealthDay News) -- Men who drink at least six or more cups of coffee a day may be cutting their risk for advanced prostate cancer by 60 percent, new research suggests.

This is the first large study looking specifically at the relationship between coffee and metastatic prostate cancer, lead researcher Kathryn Wilson said. "This is an exciting finding, because there aren't many modifiable risk factors for prostate cancer."

A definite cause-and-effect link is still far from proven, experts say, and just how coffee might help thwart prostate malignancy isn't clear.

"There are a lot of compounds in coffee that have various biological effects. It's a major source of antioxidants and that might have anti-cancer effects," said Wilson, a research fellow in epidemiology at the Harvard School of Public Health, Boston. "Also, coffee seems to have effects on insulin and has been associated with a lower risk of type 2 diabetes. In addition, insulin is thought to play a role in many cancers, including prostate cancer."

Compounds in coffee also have an impact on sex hormone levels, according to the study.

But right now, the findings point only to an association between a love of "java" and a healthier prostate. More study will be needed to confirm the findings and to see if a biological explanation for the phenomenon exists, Wilson said.

The bottom line, she said: "It's probably too early to tell someone that [he or she] should go out and start drinking coffee just because of this study."

The report was published in the May 17 online edition of the Journal of the National Cancer Institute.

Prostate cancer is the most common cancer diagnosed and the second leading cause of cancer death in men in the United States. In the U.S. it affects one in six men during their lifetime. More than 2 million Americans and 16 million men around the world are prostate cancer survivors, the researchers say.

For the study, Wilson's team collected data on almost 48,000 men who took part in the Health Professionals Follow-Up Study and followed them until 2008. Every four years from 1986 on these men reported on how much coffee they drank.

The researchers then calculated the risk for prostate cancer tied to the amount of coffee consumed. During the period of the study, they identified 5,035 cases of prostate cancer, of which 642 were fatal cases in which the cancer was metastatic, meaning that it had spread beyond the original site.

The Harvard team found that drinking six or more cups of coffee each day was associated with an almost 20 percent lower risk of developing prostate cancer, compared to those who did not drink coffee.

In addition, the odds of developing a more lethal or advanced prostate cancer dropped by 60 percent, compared to men who abstained from coffee -- a statistically significant and "substantially lower" relative risk, according to the researchers.

Even men who drank less coffee -- one to three cups a day -- had a 30 percent lower risk of developing lethal prostate cancer, and reductions in risk were observed whether the men drank caffeinated or decaffeinated coffee, Wilson's group added.

After taking into account other lifestyle factors, such as age, smoking, obesity and exercise, the decline in the odds for prostate cancer remained, they said.

"This adds to the evidence from a variety of diseases that coffee doesn't seem to be harmful," Wilson said. "It has been shown, pretty consistently, to be associated with lower risk of Parkinson disease, type 2 diabetes and liver cancer. This is another potential plus for coffee."

The study was limited by self-reported data and the lack of data on coffee intake from earlier periods of the men's lives, the researchers noted.

The finding comes on the heels of a study published last week that found that women who drank five or more cups of coffee per day saw a significant drop in their risk for a particularly aggressive form of breast tumor. The Swedish study, from a team at the Karolinska Institute in Stockholm, was published in Breast Cancer Research.

Commenting on the Harvard team's findings, Eric Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society, called it a large, well-designed study. But he stressed that, so far, it remains the only study to show such a link.

"It is premature to conclude that drinking coffee might help prevent fatal prostate cancer," he said. "We do, however, know that both smoking and obesity are associated with higher risk of fatal prostate cancer, as well as death from many other diseases. So it is fine to enjoy a nice cup of coffee, but avoiding smoking and maintaining a healthy weight are among the surest ways to stay healthy."

More information

For more information on prostate cancer, visit the American Cancer Society.

Most women don't need vitamin A pills: study

By Genevra Pittman

Reuters Health

Tuesday, May 17, 2011

NEW YORK (Reuters Health) A new study from Bangladesh has experts concluding that most of the world's women don't need vitamin A supplements.

In the developing Asian nation, giving vitamin A supplements to pregnant women in the rural north didn't cut down on their chance of pregnancy-related death, or on infant deaths, according to a new study.

Still, the researchers say making sure pregnant women get enough vitamin A through diet or supplements is "an important public health goal" for other reasons.

But experts debate whether vitamin A supplements are helpful.

"At the moment I think there's very little evidence to support the supplementation of women with vitamin A," Anthony Costello, of the University College London Institute for Global Health, told Reuters Health.

"It seems likely that either it doesn't have an effect, or it only has an effect in populations where there are really serious levels of vitamin A deficiency," said Costello, who has studied vitamin A in the past but was not involved in the current research.

"For most women in the world, that probably doesn't apply."

In the Bangladeshi study, published in the Journal of the American Medical Association, Keith West of the Johns Hopkins Bloomberg School of Public Health in Baltimore and colleagues followed a population of about 600,000 people for more than five years.

The research team identified every household in that region that had a married woman between age 13 and 45. Every 5 weeks, female staff members visited those households to find out -- through discussion and urine tests -- if any of the women were pregnant.

If they were, the staff began giving them a weekly dose of vitamin A, beta carotene, or a vitamin-free placebo pill every week until 12 weeks after they gave birth. The staff also gave all women educational materials about care and diet during pregnancy. The assignments to the various groups were done randomly, based on household location.

There were about 60,000 pregnancies during the study period, with mothers evenly distributed between the vitamin A, beta carotene, and placebo supplements.

A total of 138 women in the study died of any pregnancy-related cause. That worked out to 20 to 25 women per 10,000 pregnancies, regardless of what supplement they were taking.

Rates of stillbirths and infant deaths also did not vary based on the type of supplements pregnant women were given. Each supplement group had between 45 and 51 stillbirths for every 1,000 births, and between 65 and 70 infant deaths in the 12 weeks after birth per 1,000 live births.

Changing Need?

Vitamin A deficiency has been linked with night blindness in pregnant women and with maternal death in some regions. The World Health Organization says those risks are highest in the last three months of pregnancy. In the Bangladesh study, anyone with night blindness was treated with vitamin A, regardless of her assigned supplement.

Costello, however, thinks vitamin A deficiency in the developing world has become less of a problem over the last 30 years, in the wake of economic and agricultural changes that also affect nutrition.

Previous studies, including those by West and colleagues, looked at the effect of giving vitamin A to pregnant women in Ghana and Nepal and also found no effect on rates of stillbirth or infant mortality. The Nepal studies, however, did find that fewer pregnant women died when they were given vitamin A or beta carotene supplements.

Women in Bangladesh may already consume more foods rich in vitamin A compared to Nepalese women, West says. They have a generally smaller chance of dying in pregnancy for other reasons too -- for example, they may be more likely to have a health care worker present at their delivery.

Costello said that while vitamin A deficiency is becoming less common, supplementation is still important -- especially for warding off infection -- in people who are deficient, including young children.

"I think you can still make a case for supplementing children," he said. "But we have to be aware that as the situation changes ... the benefits of supplementation programs may gradually decline."

And, Costello said, "There's no need to go rushing off giving vitamin A to every woman in the world."

West too believes nutrition is improving in many parts of the developing world, possibly making vitamin A supplementation less essential in some places, including rural Bangladesh.

"It's still a vital nutrient. If you don't have it along with other micronutrients, things will go wrong. But the dietary profiles are changing," West told Reuters Health. "Is that true everywhere? I would say no, but it's probably a general trend."

Still, he added, "We need to remain vigilant to the nutritional needs of the rural poor...in the developing world, and prevent deficiencies."

No Magic Bullet

Dr. Prakesh Shah, who has also studied micronutrient supplements and pregnancy, takes a different message from the findings.

"Looking at one single micronutrient to have an effect on a mother dying or not dying is a little bit too much to expect," Shah, a University of Toronto researcher who was not linked to the new study, told Reuters Health.

If women and babies are going to benefit from supplements, he continued, it's going to be from a supplement with more nutrients -- including vitamin D, folic acid, and iron.

Maternal and infant death rates are still much higher in the developing world than in places like the U.S. and Canada. However, Shah said, "Are we going to find one single bullet like vitamin A and that's going to cure all the problems? That's probably not going to happen."

Source: http://bit.ly/jcvTuc

Journal of the American Medical Association, online May 17, 2011.

Obstructive Sleep Apnea Linked to Cancer Growth in Mice

ScienceDaily

Tuesday, May 17, 2011

ScienceDaily (May 17, 2011) A new study links the intermittent interruption of breathing that occurs in patients with obstructive sleep apnea (OSA) to enhanced proliferation of melanoma cancer cells and increased tumor growth in mice, according to researchers in Spain. The study also found tumor cells of OSA mouse models tended to contain more dead cells, indicating a more aggressive type of cancer.

The results of the study will be presented at the ATS 2011 International Conference in Denver.

"To our knowledge, this study is the first one providing experimental evidence that a high-rate intermittent lack of oxygen, or hypoxia, mimicking the one experienced by OSA patients enhances tumor growth," said Ramon Farre, PhD, professor of physiology at the University of Barcelona School of Medicine Biophysics and Bioengineering Lab.

Recurrent hypoxia is one of the hallmarks of OSA, which may affect around 5 percent of Americans. OSA has been associated with an increased risk of cardiovascular disease, including high blood pressure, as well as daytime sleepiness and a lower quality of life.

"Although earlier studies in animals have shown that lack of oxygen, or hypoxia, plays an important role in regulating the various stages of tumor formation and progression, the results obtained from human studies including large groups of OSA patients are not easy to interpret because there are other contributing conditions, most notably obesity," Dr. Farre added. "This well-controlled mouse model study allowed us to ensure that the only variable under study was intermittent hypoxia."

In this study, mice injected with melanoma tumor cells were divided among two groups. In the first group, mice were exposed to intermittent hypoxia, where oxygen was restricted for 20-second periods at a rate of 60 periods per hour for six hours per day, and normal oxygen levels for the remainder of the day. In the second group, mice received normal levels of oxygen (normoxia). Tumor volume was measured throughout the study and at the end of the study period. At the end of the 14-day study period, tumors from all mice were removed and weighed and tumor necrosis (indicated by the numbers of dead cells present) was measured to determine the aggressiveness of the tumors.

The authors found that while tumor volume progressively increased with time in both the intermittent hypoxia and control groups, the increase was higher in the mice subjected to intermittent hypoxia. Tumor weight and necrosis in the intermittent hypoxia group were almost two times that of the tumors in the control group.

"With the limitations of any animal model study, these results suggest that the intermittent hypoxia characterizing obstructive sleep apnea could enhance the growth of tumors," Dr. Farre said, adding that although the results were not entirely unexpected based on earlier studies connecting hypoxia with tumor growth, a link between breathing abnormalities specific to OSA and tumor progression had not previously been demonstrated.

"It was well known that continuous hypoxia promotes the growth of cancer cells and tumors," he said. "However, there were no data concerning the effects of the fast rate changes of oxygenation in sleep apnea on cancer."

Dr. Farre said the results of this study could have future clinical implications if the results are confirmed in large-scale human studies. "There are still several questions that need to be answered, both at the basic science and clinical levels," he said.

Future studies would need to evaluate whether intermittent hypoxia also triggers the initial formation of tumors and whether it promotes metastasis, or spread of tumors from one organ to another. Because this study focused on melanoma, Dr. Farre said additional studies should also explore whether intermittent hypoxia affects other types of cancer.

Extended population studies should also determine if there is a relationship between the incidence of cancer and the severity of OSA, as well as addressing the issue of obesity, which has been linked with OSA.

"Intermittent hypoxia is not the sole cancer-promoting challenge experienced by OSA patients," Dr. Farre said. "Obesity is also known to enhance cancer morbidity and mortality, and it is not clear to what extent intermittent hypoxia and obesity could interact to increase cancer growth in OSA patients.

Clarifying these questions certainly will require additional studies," he said. "If the current results in an animal model are confirmed by further clinical research, the public health impact of obstructive sleep apnea would be greater than currently known."

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff. 

Monday, May 16, 2011

Can selenium lower cholesterol?

By Genevra Pittman

Reuters Health

Monday, May 16, 2011

NEW YORK (Reuters Health) Taking high doses of selenium may help slightly lower cholesterol levels -- but it's still not recommended in the United States, where most people get plenty of the mineral, according to the authors of a new study.

Still, the finding is "reassuring" because previous research had linked high selenium with higher cholesterol levels, said study author Dr. Eliseo Guallar, from the Johns Hopkins Bloomberg School of Public Health in Baltimore.

The picture of selenium's health benefits -- or possible health risks -- has been anything but clear. Last week, a review of prior studies suggested that selenium probably doesn't help prevent cancer, but might be linked to an increased diabetes risk at high doses (see Reuters Health story of May 11, 2011.)

"We don't really know where we are," Guallar told Reuters Health. "In a sense it's a necessary micronutrient and we need it, but we might be (in) a situation where we have enough -- we might even have too much."

Selenium is found in meat, bread, and some nuts. It's also available in supplement form, and costs about $2 for a month's supply.

The Institute of Medicine recommends U.S. adults consume 55 micrograms of selenium per day.

Guallar and his colleagues wanted to look specifically at the link between selenium and cholesterol. They recruited about 500 older adults in the UK to take one of three different doses of selenium daily -- 100, 200, or 300 micrograms -- or a placebo pill with no selenium.

Researchers measured participants' cholesterol levels at the beginning of the study and after six months on the selenium supplements or placebo. Their results are published in Annals of Internal Medicine.

Participants had an average starting cholesterol of about 230 milligrams per deciliter of blood. A healthy cholesterol level is less than 200 mg/dL, according to the American Heart Association, while 200 to 239 mg/dL is considered "borderline high."

In the groups taking 100 and 200 micrograms of selenium daily, total cholesterol dropped an average of 8.5 mg/dL and 9.7 mg/dL, respectively, compared to the group taking a placebo pill.

Taking the highest dose of selenium was not linked to decreases in total cholesterol -- but it was the only dose associated with an increase in HDL ("good") cholesterol.

The authors reported no serious side effects associated with selenium during the study.

While Guallar said the results are "good news" in showing that high selenium intake is probably not a risk for high cholesterol, he wanted to add a note of caution.

The finding "is not generalizable to other patients," he said. "In a population like the U.S. where selenium levels are adequate, there's no reason to take extra selenium in supplements."

The question of the link between selenium and health outcomes, Guallar said, "is a very interesting story that's still developing."

Source: http://bit.ly/atTzv0

Annals of Internal Medicine, online May 16, 2011.

Heavy Smoking Tied to Advanced Kidney Cancer

HealthDay News

Monday, May 16, 2011

(HealthDay News) -- Smoking increases the risk of advanced kidney cancer, researchers report.

In a new study, a team from Duke University Medical Center reviewed the cases of 845 patients who had had surgery for kidney cancer -- or renal cell carcinoma -- between 2000 and 2009. They found that current and former smokers were 1.5 to 1.6 times more likely to have advanced cancer than nonsmokers.

Heavy smoking (smoking for a longer period of time and smoking more) was associated with advanced renal cell carcinoma. Kicking the habit reduced the risk of advanced disease by 9 percent for every 10 years that a former smoker was smoke-free, the investigators found.

The findings were slated for presentation Sunday at a special press conference at the American Urological Association's annual meeting, in Washington, D.C.

Another study scheduled for presentation at the same briefing found that rates of bladder cancer did not fall along with lower rates of smoking in the United States.

The researchers examined a national database and found that lung cancer rates declined along with decreasing per capita consumption of cigarettes between 1973 and 2007, but the same type of consistent decline was not seen in bladder cancer rates.

There may have been a decrease in bladder cancer due to smoking, but that decrease may have been offset by other factors contributing to a rise in bladder cancer over the last few decades, the researchers at the State University of New York Upstate Medical University in Syracuse said in a news release from the American Urological Association.

"These two studies shed new insight into the role that smoking might have for two important urologic cancers," news conference moderator Dr. Toby Kohler said in the news release.

"For kidney cancer, it is true that kidney tumors are more often being detected these days when they are smaller. However, smoking seems to confer a much greater risk that the cancer may be more aggressive. Cessation of smoking seems to lower the risk," Kohler said.

"For bladder cancer on the other hand, the decrease in smoking rates has not impacted the incidence to the same degree that it has for lung cancer, suggesting that there may be other factors which are becoming more important for the development of the disease," he added.

Because these studies are being presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The U.S. National Cancer Institute has more about bladder cancer.

Excess weight in elderly makes daily tasks harder

By Alison McCook

Reuters Health

Monday, May 16, 2011

NEW YORK (Reuters Health) Older adults who are obese are more likely to develop problems with day-to-day activities, such as bathing, getting dressed, and going to the bathroom, a new study finds.

The more excess weight they are carrying, the more likely they are to report new disabilities, according to surveys of more than 20,000 adults 65 and older.

Interestingly, being overweight did not appear to bring a higher risk of death -- except in the very heaviest -- making this one more study to suggest that moderate weight gains don't have the same impact on older people's health as they do in the general population, said study author Dr. Christina Wee of Beth Israel Deaconess Medical Center in Boston.

As a result, Wee told Reuters Health, some experts assume that the benefits from weight loss are smaller - or perhaps non-existent - in older adults. Furthermore, losing weight could be dangerous in the elderly, for instance if it causes malnutrition or bone loss, she added. "So it was not clear that, on balance, the benefits (of weight loss) would necessarily outweigh the risks."

To further investigate how carrying excess weight specifically impacts the elderly, Wee and her team reviewed information collected from 20,975 Medicare recipients during periodic interviews over a 4-year period. More than one-third of participants were overweight, and another 18 percent were obese. All participants were followed for 14 years in order to note who died.

The study focused on people's responses to questions about their ability to complete day-to-day activities, which include eating, getting in and out of chairs, and walking. The researchers separated these basic motions from so-called "instrumental" daily activities, which consisted of using the telephone, cooking, shopping, and managing money.

Reporting in the Annals of Internal Medicine, the authors found that between 22 and 32 percent of overweight and obese women, for instance, reported they were struggling more with at least one daily activity over the course of the study period, versus 20 percent of older women who were at a healthy weight.

When it came to "instrumental daily activities," between 30 and 38 percent of overweight and obese men said those activities had become harder since the study began, while only 28 percent of men without excess weight reported the same problem.

Extra weight appeared to be less associated with developing problems in daily activities among African-Americans, although their number (8 percent of the study group) was too small to be sure about the finding.

It's not clear why excess weight may have a more obvious impact on disability than on the risk of death, Wee noted. One explanation might be the presence of a "survival effect," she said, in which obese adults who live to 65 or older may be more "resistant" to death, perhaps carrying genes that help combat the effects of obesity. "But older adults are already more prone to disability and obesity might just tip the scales even more."

Indeed, the participants with the lowest risk of dying during the study period were those considered to be overweight, not obese. This finding is not particularly surprising, Wee noted - people's weight classes were determined using body mass index, which is not as accurate a measurement of body fat in the elderly as in adults in general, she said. "In addition, since many chronic illnesses in the elderly (may) lead to unintentional weight loss, being thinner may be a sign of having a lot of illnesses."

For now, it's not clear exactly what older adults who are carrying excess body fat should do about it, she noted. Their focus may not need to be on dieting, she said, but on preserving their ability to perform daily activities. "It may be the treatment is not just to lose weight (but) to get physical or exercise therapy to strengthen muscles and improve function."

Source: http://bit.ly/an7XRm

Annals of Internal Medicine, online May 16, 2011.

Common Anti-Inflammatory Coaxes Liver Cancer Cells to Commit Suicide

ScienceDaily

Monday, May 16, 2011

ScienceDaily (May 16, 2011) The anti-inflammatory drug celecoxib, known by the brand name Celebrex, triggers liver cancer cell death by reacting with a protein in a way that makes those cells commit suicide, according to a new study.

Researchers also found that the combination of celecoxib with each of two chemotherapy drugs killed more liver cancer cells in culture, making those combinations more effective than either drug on its own.

"Each chemotherapy drug alone will reduce the growth of cancer cells, but when each single drug is combined with Celebrex, a greater growth suppression effect was observed," said Jiayuh Lin, senior author of the study and an associate professor of pediatrics at Ohio State University. "For clinicians, this research suggests the possibility of a new therapeutic strategy."

Celecoxib has this effect by acting on STAT3, a gene inside liver cancer cells that, when activated, allows those cancer cells to resist the effects of chemotherapy drugs. The researchers determined that the celecoxib molecule binds to STAT3 on so-called "hot spots," effectively blocking its ability to function.

Powerful computing techniques were employed before the researchers ever considered celecoxib as a potential treatment for cancer. Celebrex is a nonsteroidal anti-inflammatory drug, or NSAID, and a Cox-2 inhibitor, meaning it helps control inflammation by inhibiting an enzyme known as cyclooxygenase-2. It is most commonly prescribed to treat the pain of arthritis.

Chenglong Li, an assistant professor of medicinal chemistry and pharmacognosy at Ohio State, has developed computer simulations to identify optimal drug fragment combinations that attach simultaneously to proteins in ways that block the proteins' functions. By searching a database of existing federally approved drugs, he found that celecoxib was structurally similar to a template molecule that he had determined would most effectively bind to STAT3 and inhibit its function.

"Normally, STAT3 is persistently activated in cancer cells. If you have a good molecule that sticks to STAT3, it will prevent its activation," Li said. And when STAT3 is inhibited, cellular survival pathways are blocked that cause the cancer cell to chop itself up and die.

The research appears online and is scheduled for later print publication in the journal Cancer Prevention Research.

The biological portion of the study further defined the role of a pro-inflammatory protein in liver cancer's development. The protein, called interleukin-6, or IL-6, is a cytokine, a chemical messenger that causes inflammation, which can have both beneficial and damaging effects in the body. Previous research by other scientists has shown that high levels of IL-6 in the blood are associated with hepatocellular carcinoma, the most common type of liver cancer.

Lin and colleagues determined that IL-6 initiates a chemical reaction called phosphorylation of STAT3. That reaction activates STAT3 inside liver cancer cells, where STAT3 in turn activates at least three other known genes that allow the cells to resist the effects of chemotherapy.

The scientists treated five different types of hepatocellular carcinoma cells with two different doses of celecoxib for two hours, and followed by giving them IL-6 for 30 minutes. The pre-treatment with the lower dose of celecoxib inhibited IL-6's ability to start the reaction that activates STAT3. The higher dose blocked STAT3 altogether.

The researchers then treated a line of liver cancer cells with celecoxib in combination with two chemotherapy drugs: doxorubicin, which is used to treat breast, ovarian, gastric, thyroid and several other cancers, and sorafenib, which is the only chemotherapy medication approved by the Food and Drug Administration for liver cancer treatment. Its brand name is Nexavar.

With both drugs, the addition of celecoxib treatment reduced the number of viable liver cancer cells by anywhere from approximately 50 percent to more than 90 percent, depending on the doses. The combination of celecoxib and sorafenib also significantly limited the cancer cells' ability to form colonies, a key element of tumor growth and survival after the drug treatment.

"Because liver cancer has a very low five-year survival rate, it is most likely that even sorafenib alone may not be effective to cure the cancer," said Lin, also an investigator in Ohio State's Comprehensive Cancer Center and the Center for Childhood Cancer at Nationwide Children's Hospital. "We hope that using both drugs together could be more effective. Both celecoxib and sorafenib are already approved by the FDA, so we think this combined treatment should be able to be used in the clinic pretty quickly."

The fifth most common cancer in humans, liver cancer remains one of the most difficult to successfully treat. Patients' overall five-year survival rate is about 10 percent, according to the American Cancer Society.

These experiments were conducted in cell cultures. Further testing would be needed to determine celecoxib's effectiveness in human cancers, Lin noted.

And the powerful computational work led by Li, also an investigator in Ohio State's Comprehensive Cancer Center, is likely to lead to the development of new molecules with even more precise structural relationships with the proteins they are designed to block.

Li's method is called Multiple Ligand Simultaneous Docking. In this work, he used computer simulations to identify "hot spots" on the STAT3 protein -- tiny pockets to which molecules could most successfully attach to inhibit the protein's activity. He then searched through drug banks containing more than 7,500 existing and experimental medications to find the most suitable molecular fragments that could be pieced together to produce a new molecule shaped in such a way that it would fit into those pockets.

After designing a template molecule that would most effectively bind to STAT3, he compared that template to the 1,400 federally approved drugs already on the market.

"Celecoxib is almost identical to the molecule template. It attaches to STAT3 in three places. We can optimize celecoxib, and that is expected to come soon. But applying our technique to find those pieces and determining that they come from an existing drug makes the discovery process much faster," said Li, a key co-author of the paper and frequent research collaborator with Lin.

Li has termed this approach as in silico (computer-driven) drug repositioning or repurposing.

The discovery that celecoxib can bind to STAT3 also appears to apply to other cancers. Both Lin and Li were key authors on a recent paper that suggested that celecoxib's ability to block STAT3's function might also make it effective as a treatment for rhabdomyosarcoma, the most common soft tissue cancer in children and adolescents. This research was published in the April 15 issue of the journal Biochemical and Biophysical Research Communications.

Co-authors of the liver cancer and rhabdomyosarcoma studies include Yan Liu, Aiguo Liu and Suzanne Reed of the Center for Childhood Cancer at Nationwide Children's Hospital (Aiguo Liu is also affiliated with Tongji Hospital at Huazhong University of Science and Technology in Wuhan, China); and Huameng Li of Ohio State's Division of Medicinal Chemistry and Pharmacognosy and the Biophysics Graduate Program.

This work was supported by grants from the National Institutes of Health and the Department of Defense Congressionally Directed Medical Research Programs.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal References:

  1. Y. Liu, A. Liu, H. Li, C. Li, J. Lin. Celecoxib Inhibits Interleukin-6/Interleukin-6 Receptor-Induced JAK2/STAT3 Phosphorylation in Human Hepatocellular Carcinoma Cells. Cancer Prevention Research, 2011; DOI: 10.1158/1940-6207.CAPR-10-0317
  2. Suzanne Reed, Huameng Li, Chenglong Li, Jiayuh Lin. Celecoxib inhibits STAT3 phosphorylation and suppresses cell migration and colony forming ability in rhabdomyosarcoma cells. Biochemical and Biophysical Research Communications, 2011; 407 (3): 450 DOI: 10.1016/j.bbrc.2011.03.014