Hypoglycemia Following Weight-Loss Surgery

By Marzieh Salehi, MD, MS, Associate professor, Division of Diabetes, UT Health San Antonio
Tuesday, July 30, 2019

Diabetes remission after weight-loss surgery is well recognized, but for a few, low blood sugars develop years afterward.

Bariatric surgery is a vital weight-loss treatment for people who have a body mass index consistently over 40, or have a BMI over 35 joined by Type 2 diabetes or other risk factors. Gastric bypass and sleeve gastrectomy are the two most commonly performed and most effective bariatric procedures to treat these patients.


By Marzieh Salehi, MD, MS
Associate professor, Division of Diabetes
UT Health San Antonio

Most patients fare well with surgical weight loss. UT Health San Antonio physicians have performed these surgeries since the 1980s. The university’s board-certified, fellowship-trained bariatric surgeons help patients reach their weight-loss goals through minimally invasive laparoscopic procedures that cause less scarring and accelerate recovery.

Gastric bypass and sleeve gastrectomy have an immediate and robust effect on glucose control in patients with Type 2 diabetes. In fact, one in three people taking diabetes medication prior to these surgeries finds they no longer need medication to control their diabetes — even before weight loss occurs.

But there is a small group of individuals who develop low glucose levels several years after bariatric surgery, particularly gastric bypass.

Estimates of prevalence vary, but reports show about 10% of bariatric surgery patients have clinically recognized hypoglycemia. A much smaller group of patients, less than 1%, have episodes severe enough to require hospitalization.

Because of low awareness about this condition, patients can spend years working with multiple providers who perform various tests, seeking the causes for their symptoms — without gaining an understanding of their condition. There have even been cases where the symptoms of hypoglycemia were labeled as mental health problems.

It is imperative that the medical community has a better understanding of this complication and is able to refer patients properly. To answer this need, we are providing this expertise in our comprehensive diabetes treatment center at UT Health San Antonio.

Hypoglycemia related to bariatric surgery typically manifests beyond the first year after surgery. Symptoms generally occur one to three hours after eating and range widely in severity, from palpitations and sweating to confusion, difficulty in speaking and thinking, and, rarely, loss of consciousness and seizures. Some people no longer can drive and have problems keeping their jobs.

Recommendations in general include dietary modification and medications that interfere with carbohydrate absorption or suppress insulin secretion. Thorough evaluation of each patient is required for proper diagnosis and individualized treatment.


Marzieh Salehi, MD, MS, is a physician specializing in endocrinology and internal medicine for UT Health Physicians, the medical practice of the Long School of Medicine at UT Health San Antonio. She is also an Associate Professor. She can be reached at salehi@uthscsa.edu.