ShortCuts- This Week in the Journals

November 10, 2008

picture-019.jpgCommentary by Erin E. Ducharme MD, PGY-1

Faculty Peer Reviewed

Daylight Saving time Saving Nobody: In addition to long known effects including confusion and annoyance, new research suggests turning the clock back an hour may actually be bad for your health. Swedish researchers sifting through 20 years of data found a significantly higher incidence of acute myocardial infarction occurring during the first three weekdays following the spring time change. The authors, appearing in the New England Journal of Medicine, blame sleep deprivation which has been shown to increase sympathetic activity and levels of proinflammatory cytokines. If the reverse holds true, and an extra hour of sleep is heart healthy perhaps residents can use this to argue for pushing back morning rounds.

Bariatric Surgery-benefits beyond fitting into those jeans: A nine-month prospective study of 43 severely obese patients who underwent bariatric surgery found restoration of insulin sensitivity and decreases in plasma leptin which mirrored decreases in body mass index. Pre-operatively 42% of the cohort demonstrated impaired left ventricular relaxation on Doppler imaging, a finding which was reversed with weight loss. Shedding pounds also led to a reversal of systemic and skeletal muscle metabolic dysregulation.

Antioxi-NOT: The Journal of the American Medical Association published disappointing results from the Women’s Antioxidant and Folic Acid Cardiovascular Study, in which 5442 US female health professionals (>= 42 years old) with preexisting or high risk of cardiovascular disease were prescribed either combination folic acid, vitamin B(6), and vitamin B(12) or a placebo for nearly 7.5 years. Daily supplementation with this presumed cancer-busting power trio did not alter overall risk of breast cancer, total invasive cancer, or deaths from cancer.

Gene Expression, Fixed Tissue and predicting HCC recurrence: Research published last week in the New England Journal of Medicine outlines a method for using formalin-fixed, paraffin-embedded tissue (a much more readily available substrate than currently required frozen specimens) as the medium for gene-expression profiling. Through this technique the authors were able to predict HCC recurrence in affected patients based on a reproducible gene-expression survival signature found in liver tissue surrounding the cancer (as opposed to tumor tissue itself). Older data combined with these findings support a new theory that previously presumed late-recurring HCC may actually represent new primary tumors in at-risk patients.

Anti-Climactic: A two-year double-blind, placebo-controlled study (n=814) found that postmenopausal women with low libido treated daily with a 300 µg testosterone patch experienced a significant but small increase in satisfying sexual encounters (an increase from baseline of 2.1 episode per 4/weeks vs 0.7 in the placebo at 24 weeks). The study, appearing in the New England Journal of Medicine, also reported increased desire and decreased distress but higher incidence of adverse androgenic effects in this treatment group. Long-term implications, including risk of breast cancer, require further study.

Women: the dirtier gender?: A typical hand harbors roughly 150 different bacterial species, according to a new University of Colorado at Boulder study appearing online in the Proceedings of the National Academy of Sciences. 51 participants, 102 human hands, more than 4700 different microbes. A mere five species were common to all study participants. Women’s palms were found to host significantly greater microbial diversity than men’s. The author’s postulate that the more acidic skin of men, altered sebaceous and eccrine gland production, different usage patterns of topical products, or hormone production may account for the gender difference.

The M.D. and D.O. that O.D.: A five year, longitudinal cohort study appearing in the British Medical Journal reports on the effectiveness of U.S. health programs designed to rehabilitate substance-abusing physicians. Roughly 100 of the 900 participants were lost to follow up, and 20% of those remaining failed treatment, typically early on. Of the 80% who successfully graduated from the rehabilitation program and returned to work, 19% relapsed over the ensuing five years. By the studies end, however, nearly three quarters were still licensed and working, suggesting effectiveness of these addiction management programs.

Take B3 B4 it’s too late?: In an effort to discover a preventive treatment for memory loss associated with Alzheimer’s, researchers studied the effects of large-dosage nicotinamide (NAD) injestion on mice with the rodent-version of this devastating human disease. Mice in the NAD arm exhibited restored cognition compared to their untreated counterparts. The compound (a derivative of the inexpensive, widely-available Vitamin B3) appears to work by reducing concentrations of tau protein thought to cause microtubule depolymerization, and increasing a particular tubulin associated with microtubule stability. A new trial to determine if these results can be repeated in humans is enrolling Alzheimer’s patients now.

Reviewed by Neil Shapiro MD, Editor in Chief, Clinical Correlations