Sex difference in the safety and efficacy of bariatric procedures: a systematic review and meta-analysis

With the prevalence of obesity alarmingly increasing, it is of primary interest to identify those factors predicting the success of anti-obesity therapeutic strategies currently adopted in clinical practice, and in particular, those of bariatric procedures showing the greatest success in terms of weight loss and maintenance in both the short and long term. Given sex-related differences in psychosocial status, hormonal homeostasis, and body fat distribution, it is likely that the response to different weight management strategies differs by sex. The objective was to elucidate the effect of sex on different bariatric procedures' efficacy and safety outcomes. Searches of PubMed, Cochrane, and Embase databases were performed, followed by hand-searching of reference lists from all relevant articles. We included all the studies evaluating the effect of bariatric procedures on body mass index loss (BMIL), and/or percentage excess weight loss (%EWL), and/or percentage excess body mass index loss, and/or percentage of responders, and/or short-/long-term complications and co-morbidity resolution, broken down by sex. Twenty-seven studies with a total of 114,919 patients were included. Men were more likely to achieve greater BMIL, consistent with higher male baseline BMI, and women were 2.87 times more likely to be classified as weight responders (95% confidence interval [CI]: 1.90-4.34), as well as to perform better in terms of %EWL (95% CI: .13-.54). Upon subgroup analysis based on bariatric procedure, women were more likely to be successful in terms of %EWL upon bioenteric intragastric balloon (BIB) placement (.72, 95% CI: .42-1.02). There was no sex difference regarding investigated co-morbidity resolution (hypertension, diabetes, and obstructive sleep apnea syndrome) or occurrence of short-term complications, whereas women were more likely to develop long-term complications, with an odds ratio of 1.97 (95% CI: 1.57-2.49). Sex does not have a clear effect on efficacy outcomes of bariatric procedures. Differentiating by procedure, BIB may be more effective in women, although results are discordant based on the weight loss outcome considered. If the short-term postoperative complication rate is similar across both sexes, long-term complications occur more frequently in women. To clarify the real effect of sex on bariatric procedure-derived health benefits, it is crucial to report sex-stratified results in future studies, as well as evaluate body composition changes that go beyond simple body weight reduction.