Intermountain’s 40-year study provides insight into weight-loss surgery

Digital Content Producer

SALT LAKE CITY — Researchers with Intermountain Health have published the findings of a 40-year follow-up study involving weight-loss surgery.

In some cases, the findings are not surprising. For example, patients that had the surgery saw a significant reduction in their risk of dying from heart disease, diabetes, and cancer when compared to people who were severely obese that did not have the surgery.

(A person is “severely obese,” says the Centers for Disease Control and Prevention, if their body mass index is 40, or higher.)

But the study also revealed a surprising link between young people who received the surgery, and suicide.

Findings from the weight-loss surgery study

The research was published in the journal Obesity. It is characterized as a retrospective study, matching people who had bariatric surgery with others of the same age and BMI who did not have the surgery.

The researchers said the benefit of reduced mortality was present in patients across the 40 years of the defined study period, in multiple categories of bariatric surgery, in males as well as females, and in those patients older than age 34 at the time of their surgery.

Specifically, those who had the surgery were 16% less likely to die early, and 29%, 43% and 72% less likely to die from cardiovascular disease, cancer, and diabetes, respectively.

“It gives us perspective on what to expect down the road,” said Nathan Richards, MD, study author and associate medical director of general surgery for Intermountain Health, “and is helpful to counsel patients about the benefits and risks of weight loss surgery other than what may happen just immediately after surgery.”

“The benefits are durable and last for years, there is staying power,” said Ted D. Adams, PhD, principal author of the study and adjunct associate professor in nutrition and physiology at the University of Utah School of Medicine.

The potential downsides of weight-loss surgery

Finally, the research reveals two potential hazards. One is the increased risk of death from chronic liver disease. This could be due in part, Dr. Adams said, because the weight-loss surgery changes how alcohol is absorbed by the body.

The other hazard involves suicide. Researchers said the potential for suicide was 2.4 times higher in the group who’d had bariatric surgery. This was seen “primarily in participants with ages at surgery between 18 and 34 years,” according to an abstract of the study. 

Richards called this finding surprising and concerning. 

“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,” Richards said.

This recommendation is notable in the wake of a recent announcement from the American Academy of Pediatrics, which noted that since the 1980s, the obesity rate among American children had tripled. 

In early January 2023, this organization announced that, for the first time, it recommended stronger treatment for obesity in young people, including medication and bariatric surgery.

Related reading: