It’s no secret that gastric bypass surgery is one of the most effective treatments for obesity. Studies have reported how it improves Type II Diabetes almost immediately after surgery and long before any significant weight loss occurs. This phenomenon is attributed to the earlier and larger insulin response to meal ingestion. If the body ingests less, then insulin changes occur.
Obesity and Insulin Resistance
When we eat food, the digestive system breaks down carbohydrates into sugar. As sugar enters the bloodstream, the pancreas produces insulin hormones for cells to be able to absorb the glucose (sugar). Fat cells structure in obese individuals gets altered, causing insensitivity to insulin.
Increased secretion of Glucagon-Like Peptide-1 (GLP-1) gut hormone in gastric bypass patients is contributed to the remission of type 2 diabetes mellitus.
Bariatric surgeries like gastric sleeve and gastric bypass restore the body’s sensitivity to insulin and remission of diabetes type 2.
The Study of Gastric Bypass Reversal
The University of Cincinnati’s researchers wanted to understand how and why these changes occur in the body after gastric bypass surgery.
The study was led by Marzieh Salehi, MD, an associate professor in the Endocrinology, Metabolism, and Diabetes division. Salehi and the study’s researchers looked at glucose metabolism in an eight-year post-surgery gastric bypass patient compared to a group of healthy controls. The study appeared in the May online edition of the Diabetologia journal.
Dr. Salehi reports that this study is so significant because the participant could ingest nutrients both through a gastric feed tube that goes through or bypasses the foregut, a re-routed stomach pouch that is attached to the small intestine or orally. This allowed researchers to test whether the route of the meal ingestion affected when the body metabolized the glucose itself.
Many experts agree that weight loss effects of gastric bypass in regards to glucose metabolism occur because of enhanced secretion and action of GLP-1. The central question remains whether this increase happens because of the rapid movement of nutrition through the reconfigured gastrointestinal tract or not.
Rapid Passage of Nutrients
The study’s main finding shows that the gastric bypass patient had increased GLP-1 action independent of the route of feed compared to healthy controls as well as increased plasma GLP-1 concentrations. The study’s researchers believe that this is most likely because of increased secretion and GLP-1 action after gastric bypass surgery and is not because of the rapid passage of nutrients into the lower gut.
Salehi does recognize that these findings do pertain to just a single-person case study. However, she believes that their findings of the increased role of GLP-1 in the insulin response are significant. Understanding the underlying reasons why gastric bypass surgery improves blood sugar levels will help develop various treatment options.
Severe Hypoglycemia and RNY Reversal
Salehi believes that in patients who have severe hypoglycemia, gastric bypass reversal is a possibility. However, with their new findings, they found that just reversing gastric bypass years after surgery may not reverse the hormone changes in the body after all. This study was performed on grants from the National Institutes of Health’s National Institute of Diabetes and Digestive and Kidney Diseases. It also is associated with the NIH National Center for Advancing Translational Sciences and the Medical Research Service of the Department of Veteran Affairs.