Genes affect weight loss drug effectiveness

What: A study conducted by researchers at Mayo Clinic shows that obese patients with specific genetic makeup had enhanced response to the weight loss drug sibutramine, while others who lack these genetic factors lost little or no weight.

The findings are published in the October issue of Gastroenterology (www.gastrojournal.org).

In this randomized, double-blind, placebo-controlled study, Mayo researchers measured the impact of two different dosage levels of sibutramine (10 or 15 mg daily) combined with behavioral therapy for 12 weeks in 181 overweight or obese participants. Participants received structured behavioral therapy for weight management at four, eight and 12 weeks.

As has been previously shown in trials with this approved medication, patients who received sibutramine and behavioral therapy lost significantly more weight than those who received placebo and the same behavioral therapy. Researchers also confirmed that weight loss at four weeks was a significant predictor of weight at 12 weeks, even after adjusting for baseline weight, gender, BMI and treatment.

Researchers explored the influence on weight and body composition of specific genetic markers indicative of variation in the function of two hormones/transmitters and an intracellular protein that mediates the function of those hormones. Patients with a certain pattern of variations of the genes lost an average of 10-12 pounds over the 12-week study, and those with unfavorable variations did worse.

Who:

Dr. Michael Camilleri, a Mayo Clinic gastroenterologist and the lead author of the study, is available for interviews. Please call Amy Tieder, Mayo Clinic Public Affairs, 507-284-5005, to make arrangements.

For audio and video:

Please also see Mayo Clinic news blog (http://newsblog.mayoclinic.org/2008/09/17/genes-weight-loss-drug-effectiveness/), password, e546f1 for audio and web video from Dr. Camilleri.

Source: Mayo Clinic