Genes linked to obesity may also cause poor weight loss outcomes after gastric bypass surgery

Researchers at Geisinger Health System are studying how genes may affect a patient's ability to lose weight following bariatric surgery. Highlighted in the journal Obesity, the study found that several genes that promote obesity may also result in inferior weight loss outcomes after gastric bypass surgery.

In a study of more than 1,000 individuals with extreme obesity (a body mass index over 35), those who had the highest BMI pre-surgery also fared the poorest after surgery. Of those individuals who fared the poorest after surgery, all where shown to have four key genes in common.

"Predicting which patients will have successful outcomes after surgery and those who won't not only has tremendous benefits for patients, since treatment will be better tailored to improve the quality of life for the growing number of patients in need of significant weight loss, but may also save money," said Christopher Still, D.O., director of the Geisinger Center for Nutrition and Weight Management, who led the study. Though bariatric surgery can lead to significant weight loss, gastric bypass procedures can cost up to $20,000 and involve significant lifestyle changes.

Dr. Still and Glenn S, Gerhard, M.D., director of the Geisinger Clinic Genomics Core and staff scientist at the Weis Center for Research, also have secured a five-year NIH grant to investigate the impact of genetics on weight loss and the genetic factors behind obesity-related diseases such as diabetes, high blood pressure and high cholesterol.

The study, conducted in conjunction with researchers from the Mid-Atlantic Nutrition Obesity Research Center at the University of Maryland, will identify molecular and genetic factors that play roles in obesity and related conditions like diabetes and non-alcoholic fatty liver disease.

"Little is known about why some people are more successful than others at losing weight and maintaining the weight loss," said Dr. Gerhard. "This study will determine whether certain genes affect how people lose weight and whether their medical problems improve. Identifying these factors may help guide which types of weight loss therapies should be performed for extremely obese individuals."

The NIH awarded more than $2 million for the five-year study, which began in March. Roughly one-third of the U.S. population is considered obese.