Intermountain Health up to 40-Year Follow Up Study Shows People Live Longer After Weight-Loss Surgery Than Patients with Severe Obesity Who Did Not Have Surgery

A new Intermountain Health study that followed patients for up to 40 years after they had bariatric weight-loss surgery found significant reduction in death rates from heart disease, diabetes, and cancer compared to matched patients with severe obesity who did not have surgery.

Findings from the study, which were published in the medical journal, Obesity, found the overall cause of death for both men and women bariatric patients was 16% lower than matched patients who did not have surgery. For cardiovascular-related deaths, the rate was 29% lower, for cancer deaths it was 43% lower, and diabetes-related deaths were 72% lower.

“The duration of the study allowed us to get a unique, long-term understanding about the role weight-loss surgery plays in caring for people with obesity,” said Nathan Richards, MD, study author and associate medical director of general surgery for Intermountain Health. “It gives us perspective on what to expect down the road and is helpful to counsel patients about the benefits and risks of weight loss surgery other than what may happen just immediately after surgery.”

Dr. Richards says the study shows that people with severe obesity who undergo bariatric surgery are less likely to die early than those who do not have surgery. 

“This study not only shows that people who have weight-loss surgery have less chance of dying from heart-related disease, diabetes, and cancer, but that the benefits are durable and last for years – there is staying-power,” said Ted D. Adams, PhD, principal author of the study from the Intermountain Health surgical specialties/digestive health clinical program and adjunct associate professor in nutrition and physiology at the University of Utah School of Medicine. 

However, the study also found evidence suggesting increased risk of death from chronic liver disease and higher death rates from suicide in patients who underwent bariatric surgery at younger ages.

When it comes to liver disease, Dr. Adams notes it is possible these findings could be in part because weight-loss surgery changes how alcohol is absorbed by the body. However, he also notes the study did not test liver health before the patients had surgery or after surgery. 

“The increased risk of suicide in younger patients who undergo surgery is surprising and concerning,” said Dr. Richards. “It underscores the importance of caring for the whole patient during the weight loss journey and really focusing on mental health care pre- and post-operatively to make sure patients understand the changes associated with surgery, weight loss and have the behavioral skills necessary to handle these changes.”

The four procedures included in the study were Roux-en-Y gastric bypass, adjustable gastric banding, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch. 

Researchers used data from the Utah Population database that included nearly 22,000 participants with bariatric surgery and without in Utah between 1982 and 2018. 

“The time period that this study covers is unique. It is really hard to collect meaningful data for over 40 years,” said Dr. Richards. “Dr. Adams and the entire research group have managed to use these data to tell a meaningful story that underscores the durability of benefits of weight-loss surgery.”

Patients who had bariatric surgery were identified through bariatric surgery practices in Salt Lake City, and through Intermountain Health and the University of Utah medical records.

“This is impactful because it shows us that bariatric surgery is not a one-hit wonder, but is instead a gift that keeps on giving,” said Dr. Richards.

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