Researchers identify amino acids that may explain the benefits of gastric bypass surgery for type 2 diabetics

Lower levels of branched-chain amino acids (BCAAs) may explain why obese individuals with type 2 diabetes who opt for gastric bypass weight loss surgery are often able to improve their blood sugar control even before they lose any weight, according to a new study out of Duke University.

The phenomenon of improved blood sugar control that precedes weight loss in gastric bypass surgery patients had confounded researchers for several years. Given the fact that diabetic improvements often occur before individuals lose any fat, which is one of the main causes of diabetes, doctors knew that another mechanism must be behind the metabolic improvements.

The new findings, which were published in the journal Science Translational Medicine, suggest that BCAAs may be involved in the process. For the study, researchers analyzed one group of obese diabetics who underwent gastric bypass surgery and compared the resultant data to those from another group who did not undergo the operation.

The results showed that surgery patients tended to have significantly lower levels of BCAAs and the aromatic amino acids phenylalanine and tyrosine. Levels of these amino acids remained lower in the surgery group even when compared to participants in the non-surgery group.

Previous studies have associated BCAAs and their metabolites with insulin resistance. Given the growing evidence, the researchers said that more information needs to be gathered about the role of these amino acids in the development of type 2 diabetes.

"The evidence is mounting that BCAAs and related metabolites are linked with insulin resistance and diabetes, and that they can cause metabolic dysfunction," said Christopher Newgard, who led the study. "The current study shows that these metabolites are also highly responsive to a very efficacious diabetes intervention - gastric bypass surgery."

The team plans to continue their research into BCAAs and will soon look at whether genetic, dietary or other environmental factors lead to elevated levels in individuals at risk for type 2 diabetes.