Why Bariatric Surgery's Mortality Risk Is Higher in Men

Men and women might see vastly different risks for death following bariatric surgery, a new study suggested.

In nearly 20,000 bariatric surgery patients, men saw a five-fold higher rate of death within 30 days of undergoing weight loss surgery compared with women (0.48% vs 0.08%, P<0.001), representing 25 deaths among male patients and 12 deaths among female patients, reported Hannes Beiglböck, MD, of the Medical University of Vienna in Austria, during the virtual European Association for the Study of Diabetes (EASD) meeting.

Of the men who underwent bariatric surgery, 3.4% (176) died during follow-up in comparison with 1.3% (191) of women.

Overall, men saw a 2.7-fold higher risk for mortality after bariatric surgery compared with women during a mean 5.4-year follow-up period (0.64% vs 0.24%).

Men also saw a significantly higher rate of death on the day of the bariatric surgery: 0.29% vs 0.05%, representing 15 men and eight women who died on surgery day.

"[Both] short-term mortality and long-term mortality was higher in men compared to women," Beiglböck said. "We think that it's because of the worse overall health at the time of the operation because men tend to be older at the operation and maybe that's the biggest influence on the mortality outcome after bariatric surgery."

However, women did see a slightly higher rate of revision operations after the initial operation, which occurred in 3.4% of women versus 2.8% of men.

"I think it's important to focus on preoperative counseling, especially for men, to empower them to undergo [surgery] earlier and maybe this will improve mortality," he added.

According to the 2018 International Federation for the Surgery of Obesity and Metabolic Disorders Global Registry Report, 74% of all bariatric surgery candidates are women. Beiglböck also pointed out that the sexes tend to have different motivations for opting to undergo such surgery. While women tended to report appearance as a main motivator for surgery, men were largely concerned with resolving medical conditions. That being said, men tend to be older, have more comorbidities, and have worse overall health when they do decide to undergo surgery compared with women.

The retrospective registry analysis was conducted in Austria and included a total of 19,901 patients who underwent bariatric surgery from January 2010 to December 2018. Of these patients, 74% were women and 26% were men, which reflects the traditional composition of bariatric surgery patients, skewing more female. At the time of operation, the mean patient age was 41.

Types of surgeries performed included open and laparoscopic sleeve gastrectomy, gastric bypass, biliopancreatic diversion, and gastric banding.

The most common procedure by far for both sexes was gastric bypass, chosen by 69% of patients, followed by sleeve gastrectomy (24%), gastric banding (6%), and biliopancreatic diversion (0.4%).

From January 2010 to April 2020, 367 (1.8%) patients died, which included 197 in-hospital deaths, 23 of which occurred on the day of the operation.

About half of the patients had cardiovascular comorbidities prior to surgery, including in 53% of men and 44% of women. Other common comorbidities included psychiatric disorders, afflicting 47% and 44%, respectively, and diabetes, seen in 41% and 32%, respectively. Malignant diseases were identified in 29% of men and 36% of women.

Beiglböck's group also found a few differences in types of medications that patients were taking in the year prior to surgery.

While more women were taking antidepressants and anxiolytics prior to surgery, more men were taking antidiabetic agents, antihypertensives, diuretics, vasodilators, beta blockers, calcium channel blockers, RAAS inhibitors, lipid-lowering agents, statins, and fibrates.

Men who died after bariatric surgery were more likely to have diabetes compared with women who died, while malignant diseases were more common in deceased women than men.

Beiglböck and colleagues pointed out that one major limitation to the analysis was an inability to include data on smoking and alcohol use; it has been established that the bariatric surgery patient population has high rates of alcohol abuse.

Comment