Weight loss surgery may raise life expectancy

For individuals with obesity, weight loss surgery may prevent premature death and improve chances of having a longer life.

In a large, 40-year retrospective study, people who underwent bariatric surgery were 16 percent less likely to die of any cause over 40 years of follow-up (mean 13.2 years) compared with those who did not undergo such procedures (hazard ratio [HR], 0.84, 95 percent confidence interval [CI], 0.79–0.90; p<0.001). [Obesity 2023;doi:10.1002/oby.23646]

There was a dramatic 72-percent drop in the number of deaths due to diabetes, reported lead study author Dr Ted Adams of the University of Utah School of Medicine in Salt Lake City, Utah, US.

Deaths attributed to cancer and cardiovascular disease were also down by 43 percent and 29 percent, respectively, he added.

Of note, Adams and his team estimated that individuals with obesity who undergo bariatric surgery could expect an increase in survival time for all-cause death of 1.3 years (95 percent CI, 0.93–1.67; p<0.001).

The study included 21,837 matched participants with obesity (mean age 42 years, 79 percent women, mean baseline body mass index 46 kg/m²) who did and did not receive bariatric surgery. The most common procedure was Roux-en-Y gastric bypass (n=15,110; 69.2 percent), followed by gastric sleeve (n=3,050; 14.0 percent), adjustable gastric banding (n=2,629; 12.0 percent), and duodenal switch (n=1,048; 4.8 percent).

Over 40 years of follow-up (median 10.8 years), 2,943 participants (13.5 percent) in the surgery group and 3,181 (14.6 percent) in the nonsurgery group died.

Minimal but meaningful gain

The findings of the present study were consistent with that of the Swedish Obesity Subjects (SOS) study, in which bariatric surgery was associated with a 23-percent lower mortality risk (HR, 0.77, 95 percent CI, 0.68–0.87; p<0.001) over a median follow-up of 20–24 years. This translated to a median increase of 2.4 years (95 percent CI, 1.2–3.5; p<0.001) in life expectancy. [N Engl J Med 2020;383:1535-1543; N Engl J Med 2007;357:741-752]

“This reduction in mortality was similar to our study,” Adams noted, adding that “when considering populations who are at increased clinical risk such as patients with severe obesity, minimal gains in mean life expectancy (ie, 1.3 years) are meaningful.

“Even with minimal benefits on overall mortality, studies have shown significantly increased quality of life after bariatric surgery,” he said. [N Engl J Med 2018;378:93-96]

Adams also pointed to other notable findings in their study. For the most part, the life expectancy advantage with bariatric surgery did not differ by procedure type. Total mortality risk relative to no surgery was halved with sleeve gastrectomy (HR, 0.49, 95 percent CI, 0.30–0.79; p=0.004) and cut by 28 percent and 15 percent with gastric banding (HR, 0.72, 95 percent CI, 0.55–0.94; p=0.017) and gastric bypass (HR, 0.85, 95 percent CI, 0.79–0.91; p<0.001), respectively.

Moreover, the benefit was significant for both women (HR, 0.86, 95 percent CI, 0.80–0.93; p<0.001) and men (HR, 0.79, 95 percent CI, 0.69–0.90; p<0.001), as well as for individuals across all age groups (35–44 years: HR, 0.83, 95 percent CI, 0.73–0.94; 45–54 years: HR, 0.67, 95 percent CI, 0.59–0.76; 55–80 years: HR, 0.75, 95 percent CI, 0.65–0.85), with the exception of those who were 18–34 years old.

A caveat

One downside to bariatric surgery is the risk of suicide, Adams acknowledged.

There was a 2.4-fold (95 percent CI, 1.57–3.68) higher hazard for suicide among participants who did vs did not undergo weight loss procedures (p<0.001), especially among those who were between 18 and 34 years old at the time of the surgical procedure.

Adams emphasized the need for more aggressive presurgical psychological screening and postsurgery follow-up, especially among bariatric surgical patients representing the 18–34-year age group.

“As a result of the decades-long durability of bariatric surgery in reducing death from all causes and reducing deaths related to cardiovascular disease, cancer, and diabetes [in] participants with severe obesity,” the present data may not only urge patients with severe obesity to go for bariatric surgery treatment but also further stimulate important research related to the discovery of physiologic and biomolecular mechanisms underlying weight loss and improved mortality with nonsurgical treatment that are similar to that achieved with bariatric surgery, according to the authors.