Genetic variant mimics effect of heart failure medications
A genetic variation, found predominantly in African Americans, protects some people with heart failure, enabling them to live longer than expected. That’s the conclusion of a research team led by investigators at the University of Maryland School of Medicine in Baltimore and the Washington University School of Medicine in St. Louis. The researchers found that the genetic variation acts just like beta-blockers, a class of drugs used to treat chronic heart failure. Study results will be available in the online version of Nature Medicine, on April 20, 2008.
In the study, the researchers found that African American heart failure patients with the genetic variation had a natural protection against death and the need for a heart transplant that is the same as the protection provided by beta-blocker therapy. Those patients who were given beta-blockers did not experience additional benefits from the medications because their own “genetic beta blockade” was already protecting them.
The researchers say their discovery adds to the accumulating evidence that genetic differences contribute to the way people respond to medications, and should encourage the use of genetic testing in clinical trials to identify people who can benefit from therapy tailored to their personal genetic makeup. “This is a significant development in our understanding of why some African American patients appear to not respond to beta-blockers in the same way as Caucasian patients,” says one of the study’s co-authors, Stephen B. Liggett, M.D., professor of medicine and physiology at the University of Maryland School of Medicine and director of its cardiopulmonary genomics program. “In this case, it seems that this genetic variation is a good thing, mimicking drugs that are frequently used to treat heart failure,” says Dr. Liggett.
Major discovery in the treatment of aortic valve stenosis
A team of scientists from the Université de Montréal and the Montreal Heart Institute Research Centre, led by Dr. Jean-Claude Tardif, has completed an important study that show how a new type of medication can lead to an improvement in the aortic valve narrowing.
This type of treatment based on raising high-density lipoproteins (HDL), the so-called good cholesterol level in patients suffering from aortic valve stenosis, could potentially transform the treatment approach of this disease, notably by avoiding open heart surgery. Study results have been published on-line in the British Journal of Pharmacology.
Aging Men Can Reduce Health Risks Through Physical Activity
Our results suggest that moderate to vigorous physical activity may reduce the risk of benign prostatic hyperplasia (BPH) or lower urinary tract symptoms (LUTS) by as much as 25% relative to a sedentary lifestyle. Although the strength of the association appears to be greater with higher levels of activity, there was a non-significant trend toward a protective effect with even light physical activity. Adjustment for multiple confounders in the studies included in this analysis underscores the independence of the protective effect of physical activity on the BPH/LUTS complex.
The notion that physical activity and other modifiable lifestyle factors may alter the risks and severity of BPH and LUTS challenges traditional etiological paradigms and intimates the need for the development of new pathogenic models for the BPH/LUTS disease complex. The assumption that BPH and LUTS are relatively immutable consequences of aging—driven by a combination of genetic predisposition, androgens, and estrogens—underpins prior models. While genotype and hormones are important components, the relationship of physical activity with BPH/LUTS demands consideration of additional modulators of these processes.
It is possible that physical activity influences prostate growth pathways through alterations in hormone levels. However, we believe a more likely explanation is that physical activity exerts beneficial effects through improved cardiovascular health.
