Indian Medicine

NEW YORK (Reuters Health) - A high intake of trans fats could increase colon cancer risk, according to new research published in the American Journal of Epidemiology.

People who ate the most trans fatty acids were more likely to have pre-cancerous growths or polyps in their colons than those who consumed the least, Dr. Lisa C. Vinikoor of the University of North Carolina in Chapel Hill and colleagues found. "These results provide further support for recommendations to limit consumption of trans-fatty acids," they conclude.

Trans fats are formed by processing vegetable oils to increase their shelf-life, and are found in many baked goods, crackers, snacks and other packaged foods. Eating them increases levels of "bad" LDL-cholesterol, and hence heart disease risk. US food producers are now required to list the amount of trans fat contained in their products, and health authorities recommend people avoid eating trans fats entirely.

While there has been little research on whether trans fats boost colorectal cancer risk, there are many possible ways that they could do so, for example by changing the normal balance of fatty or bile acids in the colon, Vinikoor and her colleagues say.

To investigate a possible link, they looked at 622 people who had colonoscopies at University of North Carolina Hospitals in 2001 and 2002. Study participants were interviewed about their diet, physical activity and other health issues within 12 weeks of having the screening test.

People in the top fourth based on trans-fatty acid consumption, most of whom took in 6.54 grams daily, were 86 percent more likely to have colon polyps than those in the bottom quartile for trans fat intake, for whom median intake was 3.63 g, the researchers found. There appeared to be a threshold effect, with no increased risk seen for people in the bottom three quarters of fatty acid consumption.

Among the 38.5 percent of study participants found to have colon polyps, average trans fatty acid intake was 4.97 g, while most consumed 4.12 g. Average intakes for people who were free of the colon growths was 4.42 g, while the median was 3.61 g.

These results suggest that consumption of high amounts of trans-fatty acid may increase the risk of colorectal polyps, the researchers write, adding that the findings also back current recommendations to limit trans fat intake.

SOURCE: American Journal of Epidemiology, August 1, 2008.

Copyright © 2008 Reuters Limited.

NEW YORK (Reuters Health) - The blood pressure drug valsartan (sold as Diovan) safely and effectively lowers blood pressure in youngsters aged 1 to 5 years who have high blood pressure (also called hypertension), a study shows.

"The blood pressure reductions produced by valsartan were clinically relevant and did not cause adverse effects," Dr. Joseph T. Flynn, from Children's Hospital and Regional Medical Center, Seattle, Washington, told Reuters Health.

Hypertension is rare in young children, typically caused by underlying kidney disease or other secondary causes. The current study provides the first clinical trial results of a blood pressure-lowering medication in children younger than 6 years.

The study involved 90 children with high blood pressure who were an average of 3 years old. In most of them, high blood pressure was caused by kidney disease. During the 54-week study, children took either valsartan at different doses or a dummy pill.

Valsartan treatment led to statistically significant reductions in blood pressure in the majority of children, Flynn and colleagues found.

According to the investigators, all of the valsartan doses evaluated were well tolerated. The overall incidence of drug-related side events was low and did not differ significantly for placebo- and valsartan-treated children, and the majority of adverse events were mild or moderate and transient in nature.

In particular, valsartan had no demonstrable negative effects on growth, weight gain, or progression of head circumference -- a key indicator of brain growth in young children, Flynn and colleagues report in the journal Hypertension, published by the American Heart Association.

The study was funded by Novartis Pharmaceuticals.

SOURCE: Hypertension, August 2008.

Copyright © 2008 Reuters Limited.

NEW YORK (Reuters Health) - A type of psychotherapy called cognitive-behavior therapy, or CBT, seems to reduce insomnia and fatigue and improve the overall quality of sleep in patients undergoing dialysis treatment, a study shows. CBT can be an effective non-drug therapy for dialysis patients with sleep problems, the investigators say.

Dialysis is a procedure that people with failing kidneys must undergo in order to remove toxins from the bloodstream. More than half of people with advanced kidney disease receiving dialysis treatment suffer from insomnia and other sleep disturbances.

Sleep disturbance in dialysis patients is a "puzzling and prevalent complaint," study chief Dr. Hung-Yuan Chen from National Taiwan University Hospital, Taipei, told Reuters Health. "However, only hypnotics are available for clinicians to solve this problem at present."

Given that CBT has been proven effective for chronic insomnia in the elderly and in patients with cancer or chronic pain, Chen's team investigated the effect of CBT on sleep disturbance in patients with insomnia who were on dialysis for longer than 90 days.

All 24 study patients received "sleep hygiene" education before the 4-week study, and 13 of them were randomized to an intervention group that also received four 1-hour-weekly psychiatrist-led CBT treatment sessions. Participants who were on low-dose hypnotics long-term before entering the study were maintained at the same dose during the study.

After 4 weeks, there was an "impressive" trend toward improvement in sleep based on standard tests, although the results were not statistically significant, the team reports in the American Journal of Kidney Diseases.

Nearly 80 percent of patients in the CBT group experienced favorable changes in their sleep habits. Fatigue was also less of a problem for the CBT patients.

The CBT group but not the control group also saw declines in levels of a blood protein linked to inflammation called interleukin-1-beta.

The current study, Chen and colleagues say, provides "novel evidence" that treating dialysis patients with insomnia with CBT, in addition to an extreme low dose of hypnotics, "may not only improve sleep quality and daytime fatigue, but also alter levels of circulating biomarkers of inflammation in this population."

SOURCE: American Journal of Kidney Diseases, August 2008.

Copyright © 2008 Reuters Limited.

NEW YORK (Reuters Health) - In pregnant women, pelvic floor muscle training for bladder-control problems, though beneficial initially, is ineffective over the long term, research shows.

Stress-related urinary incontinence "is a risk factor for long-term leakage but not necessarily enough to require surgery," Dr. Robert M. Freeman from Derriford Hospital, Plymouth, UK told Reuters Health. Performing exercises before delivery designed to strengthen the pelvic floor muscles "does not seem to give good long-term results, and this is probably due to poor compliance," Freeman noted.

The findings are based on 230 women who participated in two studies of the effectiveness of pelvic floor muscle training for preventing stress urinary incontinence after pregnancy.

At 3 months after pregnancy, significantly fewer women who performed pelvic floor muscle exercises reported post-delivery urinary incontinence, compared with women who did not perform these exercises (19 percent versus 33 percent).

Eight years later, however, urinary incontinence was reported by a similar percentage of women in the pelvic floor muscle training group and the control group (35 percent and 39 percent, respectively).

More than two-thirds of the women in the training group reported that they still performed pelvic floor muscle training at 8 years, and more than a third said they were performing the exercises at least twice a week.

Despite these reports, the investigators say, incontinence rates did not differ between those performing pelvic floor exercises at least twice weekly and those performing the exercises less frequently.

"We are concerned that a lot of the evidence for both (before delivery and after delivery) pelvic floor muscle training suggests poor long-term effect," Freeman said. "We believe that compliance is the major issue, and this can only be improved by education."

SOURCE: BJOG: An International Journal of Obstetrics and Gynaecology, July 2008.

Copyright © 2008 Reuters Limited.

NEW YORK (Reuters Health) - While influenza vaccination does provide protection against catching the flu, it does not have a major impact on death in the elderly, contrary to what some studies have suggested, a new study suggests.

In prior studies, an impressive 50 percent reduction in death from any cause had been noted in elderly people who got a flu shot, but some researchers were skeptical of this degree of benefit, suggesting that it may have been the result of the "healthy user effect." The new study supports this line of thinking.

The study included more than 700 elderly people, half of whom had gotten a flu shot and half of whom had not. After controlling for a variety of factors that were largely not considered or simply not available in previous studies, the researchers concluded that any death benefit "if present at all, was very small and statistically non-significant and may simply be a healthy-user artifact that they were unable to identify."

"The healthy-user effect," study chief Dr. Sumit Majumdar of the University of Alberta in Edmonton, Canada explained in a statement, "is seen in what doctors often refer to as their 'good' patients -- patients who are well-informed about their health, who exercise regularly, do not smoke or have quit, drink only in moderation, watch what they eat, come in regularly for health maintenance visits and disease screenings, take their medications exactly as prescribed -- and quite religiously get vaccinated each year so as to stay healthy. Such attributes are almost impossible to capture in large scale studies using administrative databases."

"Over the last two decades in the United Sates, even while (flu) vaccination rates among the elderly have increased from 15 to 65 percent, there has been no commensurate decrease in hospital admissions or all-cause mortality," added co-investigator Dr. Dean T. Eurich, who is also with the University of Alberta.

"Further, only about 10 percent of winter-time deaths in the United States are attributable to influenza, thus to suggest that the vaccine can reduce 50 percent of deaths from all causes is implausible in our opinion," he added.

The study involved 352 patients given the vaccine and 352 matched control subjects. Overall, 85 percent of patients were over 64 years of age. Severe pneumonia was seen in 29 percent of patients and 12 percent of the patients died.

Flu vaccination was, in fact, associated with reduced mortality of about 50 percent (8 percent vs. 15 percent mortality in the vaccinated and unvaccinated groups, respectively), and this finding did not change after accounting for age, gender, or co-existing illnesses.

However, after adjusting for other potential confounders, including functional and socioeconomic status, the mortality reduction was weakened and no longer statistically significant.

"Previous studies were likely measuring a benefit not directly attributable to the vaccine itself, but something specific to the individuals who were vaccinated -- a healthy-user benefit or frailty bias," Eurich concluded in a statement.

SOURCE: American Journal of Respiratory and Critical Care Medicine, September 2008.

Copyright © 2008 Reuters Limited.