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13-08-2012 | Article

Global medical news in review: August 5-11, 2012

MedWire News: A roundup of select stories of interest to US physicians from the Merck Medicus Medical News wire.

Exercise boosts mood of heart failure patients

Structured exercise achieves modest reductions in depressive symptoms relative to usual care among patients with heart failure, the results of a randomized-controlled trial show.

Although the clinical significance of this small benefit is not known, it was consistent over a year and unlikely to be due to daily fluctuations, report James Blumenthal (Duke University Medical Center, Durham, North Carolina) and colleagues in JAMA.

The HF-ACTION trial included 2322 stable heart failure patients who were treated at 82 medical centers in the USA, Canada, and France.

Patients were randomized on a 1:1 basis to either supervised aerobic exercise with a goal of 90 min/week for months 1-3, followed by home exercise with a goal of 120 min/week or more for months 4-12, or to education and usual guideline-based heart failure care.

Depression was assessed at the start of the study and at 3 and 12 months' follow-up using the Beck Depression Inventory (BDI)-II, where scores ranged from 0 to 59 and 14 or higher was taken as clinically significant.

Blumenthal et al found that the median BDI-II score at study entry was 8 and 28% of the sample had BDI-II scores of 14 or higher.

After 3 months, patients in the aerobic-exercise group achieved a mean BDI-II score of 8.95, significantly lower than their peers in the usual-care group at 9.70. A similar pattern was found at 12 months, with respective scores of 8.86 versus 9.54.

In a subset of patients with clinically significant depressive symptoms, BDI-II scores at 3 months were 16.66 versus 17.98 in the aerobic-exercise versus the usual-care group, and at 12 months were 15.85 and 17.34, respectively.

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Oncology drug flushes out HIV

The addition of vorinostat to current antiretroviral therapy (ART) regimens can potentially help to eradicate hidden pockets of dormant HIV, according to study results published in Nature.

David Margolis (The University of North Carolina at Chapel Hill, USA) and colleagues hypothesized that vorinostat could reduce latent HIV infection in vivo.

Eight patients were identified who had been on ART for at least 6 months and in whom an induction of HIV RNA expression following in vitro exposure to vorinostat could be measured. The patients were given a single dose of vorinostat 200 mg followed by a single 400 mg dose 2 to 4 weeks later, and a second 400 mg dose 4 to 5 weeks after that. Circulating resting CD4+ T cells were then isolated and assessed.

When the resting CD4+ T cells were exposed to vorinostat, there was a mean 4.8-fold increase in HIV RNA expression. Significant increases compared with levels of RNA expression at baseline were noted in all patients. In two patients who underwent leukapheresis 3 to 4 months after being given vorinostat, there was a significant decline in HIV RNA expression. Vorinostat was well tolerated and only mild adverse events were noted.

The authors comment that "these observations support the conclusion that the increase in HIV RNA expression was causally related to vorinostat exposure," and that "the quiescence of latent, integrated HIV provirus within resting CD4+ T cells, a significant barrier to the eradication of HIV infection, can be disrupted by an achievable and tolerable exposure to an HDAC inhibitor."

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Back pain sufferers respond quickly to chiropractic therapy

Patients with low back pain (LBP) undergoing chiropractic treatment who respond to it are likely to improve very quickly, study findings show.

This appears to be true for those with acute (<4 weeks) and chronic (>3 months) pain.

The researchers found that treatment response on the Patient Global Impression of Change (PGIC) scale 1 week after treatment was a good indicator of outcome.

Indeed, patients with chronic and acute LBP who were "much better" or "better" on the PGIC scale at 1 week were four to five times more likely to be improved at both 1 and 3 months after treatment than patients who had not improved at 1 week.

Cynthia Peterson (University of Zurich, Switzerland) and colleagues point out that "an important and unique finding in this current study is that although 123 (23%) of the patients with acute LBP and 71 (24%) of the patients with chronic LBP were diagnosed by their chiropractors as having radiculopathy, this finding was not a negative predictor of improvement."

The team investigated the outcomes of 523 patients with acute LBP and 293 with chronic LBP receiving chiropractic treatment.

After 1 week of treatment, 65% of patients with acute pain and 32% of patient with chronic pain reported that they were either "much better" or "better." The respective rates were 81% and 59% at 1 month and 88% and 69% at 3 months, report the researchers in the Journal of Manipulative and Physiological Therapeutics.

The most consistent factor predicting outcome was self-reported improvement at 1 week, which was independently associated with improvement at 1 month (odds ratio [OR]=2.4 for acute LBP and 5.0 for chronic LBP) and 3 months (OR=2.9 and 3.3, respectively).

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Caffeine may improve motor symptoms in Parkinson's

Caffeine treatment may improve motor symptoms in patients with Parkinson's disease (PD), suggest surprise results from a randomized, controlled trial designed to assess the effects of caffeine on excessive daytime sleepiness in PD patients.

The study failed to support a benefit for caffeine in this indication, however, and motor severity was only a secondary endpoint.

"Nevertheless, these findings are noteworthy, the first to suggest antiparkinsonian effects of caffeine in a randomized clinical trial," says Michael Schwarzschild (Massachusetts General Hospital, Boston) in an editorial accompanying the study published in Neurology.

The 61 study participants took caffeine 100 mg twice daily for 3 weeks and 200 mg twice daily for another 3 weeks, or matching placebo. Over this period the Unified Parkinson's Disease Rating Scale (UPDRS) score improved by an average of 4.69 points among patients taking caffeine relative to those taking placebo.

Also, the objective motor component improved by 3.15 points, and the effect was evident after 3 weeks of 100 mg caffeine, at which point the motor component had improved by 2.96 points in the caffeine group relative to the placebo group. Caffeine had significant effects on the bradykinesia and rigidity UPDRS subcomponents, without having an adverse effect on tremor, report Ronald Postuma (McGill University, Montreal, Canada) and colleagues.

There was a nonsignificant improvement in somnolence outcomes in the intent-to-treat analysis, with a 1.71-point improvement on the Epworth Sleepiness Scale among patients in the caffeine versus the placebo group. After excluding protocol violations, this became a "modest" although significant 1.97-point improvement.

The beneficial effects of caffeine are thought to occur via adenosine receptor antagonism. Schwarzschild notes that other, more specific adenosine A2A receptor antagonists in development reportedly have antiparkinsonian benefits, but says: "Such benefits should be substantial to offset the unmatchable advantages of caffeine's long-term safety experience and cost."

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Disinfectant tackles MRSA, other bugs

Research shows that the polyhexamethylene-guanidine hydrochloride (PHMGH)-based disinfectant Akwaton effectively destroys Bacillus subtilis spores even at low concentrations.

The results, published in the Journal of Medical Microbiology, add to previous findings demonstrating that similar concentrations of Akwaton can eliminate Methicillin-resistant Staphylococcus aureus and Escherichia coli.

As well as being fast acting, Akwaton is non-toxic to humans at the tested concentrations and has been shown to be environmentally safe.

"All these properties make it an ideal disinfectant for hospitals and laboratories. It may also have great value in the food industry to tackle spore-forming food pathogens such as Bacillus cereus and Clostridium perfringens," explained study author Mathias Oulé (Université de Saint-Boniface, Winnipeg, Manitoba, Canada) in a press statement.

Oulé and team tested the sporicidal properties of Akwaton against B. subtilis spores suspended in water and attached to surfaces such as stainless steel or glass.

They found that the minimum sporostatic concentration, the minimum sporicidal concentration, and the time required for sporicidal activity were 0.06% (w/v), 0.08% (w/v), and 8.5 minutes, respectively.

A disinfectant concentration of 0.44% (w/v) killed all spores in a water suspension within 90 seconds and a concentration of 0.24% (w/v) killed all spores within 3 minutes, with equal efficacy seen at concentrations below 0.10% (w/v) if left for longer periods of time.

A higher concentration of Akwaton was needed to kill all spores on glass or stainless steel surfaces within the same time periods, with minimum concentrations of 0.52% (w/v) and 0.36% (w/v) for 90-second and 3-minute exposures, respectively.

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Digital rectal exams on the wane?

Rates of digital rectal examination (DRE) are low in clinical practice and levels of sufficient training in the technique may be in decline, the results of a US study suggest.

When asked, physicians had performed an average of only 41 DREs in the preceding year, which ranged from a mean of 29 per year for those with less than 4 years' postgraduate experience, to 123 in those practicing for over 20 years. Only three in 10 physicians stated they were completely comfortable performing a DRE.

"The findings suggest that a simple yet effective diagnostic bedside examination technique is underutilized, and, for those with recent training, is becoming inadequately taught," say Reuben Wong (University of North Carolina, Chapel Hill, USA) and colleagues, writing in the American Journal of Gastroenterology.

The study included 196 final-year medical students and 436 clinicians, specializing in gastroenterology, internal, and primary medicine. The researchers found a wide variation in the number of DREs performed in the past year by participants, ranging from seven in students to 173 in practicing gastroenterologists.

Senior physicians were more likely to perform DREs than their less experienced colleagues and were also more likely to say that they had received adequate training. For example, those who described their training as "a little" were on average 5.5 years out of medical school compared with 11.5 years for those who described their training as "completely sufficient."

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Yes, junk food makes you dumber

Researchers from down under say that a junk food diet early in childhood appears to be bad for mental development.

Lisa Smithers (University of Adelaide, Australia) and colleagues assessed data on 7097 children from the Avon Longitudinal Study of Parents and Children (ALSPAC), and examined dietary patterns for the children using parental questionnaires completed at 6, 15, and 24 months of age.

When the children were aged 8 years, the Wechsler Intelligence Scale for Children was used to measure IQ.

The team found that children who were breastfed at 6 months and who had a healthy diet including foods such as fruit and vegetables, legumes, and cheese at age 15 and 24 months had an IQ that was up to two points higher at 8 years of age than those who had a diet high in junk foods such as biscuits, chocolate, sweets, soft drinks and chips during the same period.

There was some indication that ready-prepared baby foods might have a negative effect on later IQ when given at 6 months of age, but not at 15 or 24 months.

"While the differences in IQ are not huge, this study provides some of the strongest evidence to date that dietary patterns from 6 to 24 months have a small but significant effect on IQ at 8 years of age," said Smithers.

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Weight training boosts power of exercise to reduce diabetes risk

Men who engage in weight training are at a reduced risk for Type 2 diabetes, especially if they combine this with aerobic exercise, show study findings.

A reduction in risk was achieved even with modest amounts of weight training, and adding weight training to aerobic exercise conferred an even greater benefit, say Frank Hu (Harvard School of Public Health, Boston, Massachusetts) and colleagues.

In an analysis of self-reported data obtained over 18 years as part of the Health Professionals Follow-up Study, Hu et al found that 2278 of 32,002 men developed diabetes.

As reported in the Archives of Internal Medicine, multivariate analysis that included adjustment for aerobic exercise revealed a dose-response relationship between the amount of time spent weight training and the decrease in risk for diabetes.

Men who weight trained for 1 to 59, 60 to 149, and at least 150 minutes were 12%, 25%, and 34% less likely, respectively, to develop diabetes compared with men who did not weight train at all.

The respective risk reductions for men who performed aerobic exercise for these amounts of time were 7%, 31%, and 52%.

However, men who adhered to at least 150 minutes or more per week of both aerobic exercise and weight training had an even greater diabetes risk reduction, of 59%.

The researchers also found that the association between weight training and diabetes was stronger in men aged under 65 years, which may be because the intensity of weight training decreases at older ages, they suggest.

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By Neil Osterweil, MedWire Reporter