Men had a much higher rate of death following bariatric surgery performed in Austria during 2010-2018, compared with women in a retrospective analysis of nearly 20,000 patients based on health insurance records.
The reason may be that men undergoing bariatric surgery have “worse overall health at the time of surgery” than women, Hannes Beiglböck, MD, suggested at the annual meeting of the European Association for the Study of Diabetes.
The results also showed that “men tend to be older [at time of surgery] and that might have the biggest impact on outcomes after bariatric surgery,” said Dr. Beiglböck, a researcher in the division of endocrinology and metabolism at the Medical University of Vienna.
The findings confirm those of prior studies in various worldwide locations, he noted; that is, men undergoing bariatric surgery tend to be older than women and have more comorbidities and perioperative mortality.
Dr. Beiglböck also highlighted earlier reports that indicate “profound” sex-specific differences in why patients undergo bariatric surgery, with men often driven by a medical condition and women motivated by appearance.
Hence, for men, it may be important to focus on preoperative counseling to try to get them to think about bariatric surgery earlier, “which may improve their postsurgical mortality rate,” he observed.
Nearly threefold higher mortality among men
Dr. Beiglböck and associates used medical claims data filed with the Austrian health system, which includes nearly all residents. In 2010-2018, 19,901 Austrian patients underwent bariatric surgery, and researchers tracked their outcomes for a median of 5.4 years, through April 2020.
During the 9-year period, 74% of patients who underwent bariatric surgery were women, again, a finding consistent with prior reports from other countries.
The 5,220 men were an average of 41.8 years old, with 65% undergoing gastric bypass and 30% gastric banding. The 14,681 women were an average of 40.1 years old, with 70% undergoing gastric bypass and 22% gastric banding.
During follow-up, 367 patients (1.8%) died. Among men, the overall mortality rate was 2.6-fold higher, compared with women (1.3% vs. 3.4%) and average mortality per year was 2.8-fold higher (0.64% vs. 0.24%).
The rate of death on the day of surgery among men also substantially exceeded that of women (0.29% vs. 0.05%), as did death within 30 days of surgery (0.48% vs. 0.08%). All of these between-sex differences were significant.
Baseline prevalence of four categories of comorbidities and how these differed by sex among patients who died during follow-up was also examined. Underlying cardiovascular disease was prevalent in 299 patients (81% of the deceased group), 200 (54%) had a psychiatric disorder, 138 (38%) had diabetes, and 132 (36%) had a malignancy.
The prevalence of cardiovascular disease and psychiatric disorders was roughly the same in men and women. Men had a significantly higher prevalence of diabetes, and a higher proportion of women had a malignancy.
Consistent with U.S. studies
A U.S. report in 2015 documented a higher prevalence of comorbidities and more severe illness among men undergoing bariatric surgery, compared with women, noted session chair Zhila Semnani-Azad, PhD, a researcher in the department of nutrition at Harvard School of Public Health in Boston.
“I think the [Austrian] data presented have relevance to the U.S. population,” Dr. Semnani-Azad said in an interview.
“The main limitation of these univariate analyses is they don’t account for potential confounding variables that could affect the association, such as lifestyle variables, age, and family history. There is always potential for other variables” to influence apparent sex-specific associations, she commented. Another limitation is the small total number of deaths analyzed, at 367.
“These results are a good starting point for future studies. More work is needed to better understand the impact of comorbidities and sex on postsurgical mortality,” Dr. Semnani-Azad concluded.
Dr. Beiglböck and Dr. Semnani-Azad have reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.