A group of doctors and healthcare professionals perform surgery on a patient in an operating roomShare on Pinterest
A study with a 40-year follow-up found a link between bariatric surgery and a significant reduction in death rates. Harold M. Lambert/Getty Images
  • Bariatric surgery — also known as weight loss surgery — has been in practice since the 1950s.
  • Researchers from the University of Utah found people who received bariatric surgery showed significant reductions in death rates from all causes and cause-specific conditions up to 40 years later.
  • Scientists found an 83% increase in death rates from chronic liver disease in people who had bariatric surgery.
  • And researchers also found young people who received bariatric surgery had a higher suicide rate.

Bariatric surgery, which refers to different weight loss surgery techniques, has been in practice since the 1950s. Doctors conducted more than 198,000 bariatric surgery procedures in the United States in 2020.

While weight loss surgery can have life changing — and even life-saving — outcomes for patients, the procedures also have potential risks.

Now a new retrospective study from the University of Utah finds people who received bariatric surgery showed significant reductions in death rates from all causes and cause-specific conditions such as cardiovascular disease, diabetes, and cancer up to 40 years after surgery.

However, scientists found death rates from chronic liver disease in people who received weight loss surgery were 83% higher than in people who did not have the surgery. And young people ages 18 to 34 who received bariatric surgery had an increased suicide rate than those who did not have surgery.

The study appears in Obesity, the official journal of The Obesity Society.

Bariatric surgery is an umbrella term for different weight loss surgery procedures. These include:

Depending on the type of surgery, the body is changed to alter how much food a person can eat at one time and how the food is absorbed, aiding in weight loss.

Previous studies show bariatric surgery can have additional benefits, including a reduction in major adverse cardiovascular events, type 2 diabetes remission, and increased sex drive.

And weight loss surgery has been shown to positively impact sleep apnea, depression, and joint pain.

Potential downsides to bariatric surgery include surgery-related issues such as bleeding, infections, obstructions, leaking, or blood clots. Additionally, some people who have bariatric surgery experience acid reflux, nausea, vomiting, and the inability to eat certain foods.

For this study, researchers examined data from almost 22,000 people who received bariatric surgery in Utah between 1982 and 2018. Researchers compared this data to those who had not had bariatric surgery but were matched in terms of age, sex, and body mass index.

Upon analysis, scientists found that all-cause mortality was 16% lower in people who had undergone bariatric surgery than those who had not. Additionally, researchers reported the death rate for people who had weight loss surgery decreased by 29% for cardiovascular disease, 43% for cancer, and 72% for diabetes compared to people who had not had the surgery.

Medical News Today spoke with Dr. Ted D. Adams, adjunct professor in the Department of Internal Medicine and adjunct associate professor in the Department of Nutrition and Integrative Physiology at the University of Utah, and corresponding author of this study:

“We believe that the improved mortality in the bariatric surgery patients compared to the matched non-surgery subjects for cardiovascular disease, cancer, and diabetes further support improved comorbidities — heart disease, cancer, and diabetes — and reduced incidence of these illnesses following bariatric surgery.”

“That is, improved comorbidities and reduced incidence of these specific diseases following bariatric surgery appear to be linked with improved long-term mortality for these causes,” Dr. Adams added.

Also, during the study, Dr. Adams and his team found death rates from the chronic liver disease were 83% higher in people who had received bariatric surgery than those who had not.

Dr. Adams emphasized that researchers did not extract any clinical data related to the liver status or liver function of the subjects before surgery, nor did they extract any clinical data related to alcohol use.

“As a result, the reason for increased death from liver disease is not known and can only be speculated,” he explained. “There are some studies that suggest following certain types of bariatric surgery there is increased disinhibition and impulsivity and increased rates of absorption of alcohol after specific types of bariatric surgery.”

“The increased mortality of cirrhosis of the liver was primarily seen in the surgical patients who had surgery when they were ages 18 to 34 years, compared to the matched non-surgery patients,” Dr. Adams added. “This finding may promote increased research interest.”

And this new research also uncovered a higher death rate from suicide in younger people who had bariatric surgery. Dr. Adams and his team found that those aged 18 to 34 who had received bariatric surgery had a hazard ratio for suicide 2.4 times higher when compared to young people who had not had weight loss surgery.

“Unfortunately, this study did not extract any pre-surgical or post-surgical psychological-related data. The findings may further encourage the inclusion of psychological/behavioral screening prior to the surgery, especially in patients who are seeking surgery at younger ages.

“In addition, additional post-surgical follow-up of [the] psychological/behavioral nature of specific patients may be warranted,” he added. “There appears to be an important need for additional research directed at understanding why the increased rates of suicide occurred in the patients who had their surgery when in the younger age range.”

MNT also spoke about this study with Dr. Mir Ali, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA.

Dr. Ali said the reduced death rates for all causes and cause-specific conditions reaffirm the long-term benefits of weight loss surgery for people who meet the criteria.

“Obesity essentially affects every organ throughout the body and increases (the) risk for every type of complication, even cancer,” Dr. Ali explained. “And by losing weight, they’re able to reverse those changes that occur. And the most effective way is surgery for patients who meet the criteria for surgery.”

When asked about the increased death rate from chronic liver disease, Dr. Ali said sometimes the liver and other organs may become damaged before the patient receives weight loss surgery.

“Just losing the weight may not reverse the damage that (has) already been done, but it’s something that really needs to be studied further,’ he added.

And when asked about the higher suicide rate in younger people who received bariatric surgery, Dr. Ali said although most programs require surgical candidates to undergo psychological screening, the medical community needs to be more diligent in looking for subtle clues for those who may be at higher risk.

“It is something that has been known for some time,” he continued. “We have to do a better job of screening those people and finding a way to prevent that.”