Bariatric surgery associated with decreased all-cause mortality and lower rates of other obesity-related events

Référence

Wiggins T, Guidozzi N, Welbourn R, Ahmed AR, Markar SR. Association of bariatric surgery with all-cause mortality and incidence of obesity-related disease at a population level: A systematic review and meta-analysis. PLoS Med 2020;17(7):e1003206.

Sommaire

These authors searched PubMed, EMBASE, and the Web of Science for national or regional administrative database studies that evaluated mortality or incident obesity-related diseases for patients who have undergone any form of bariatric surgery. They defined obesity-related illnesses as type 2 diabetes, hypertension, obstructive sleep apnea, ischemic heart disease, cardiac failure, dyslipidemia, and venous thromboembolism. The authors excluded randomized trials, but the included studies had to have a control group and a minimum of 18 months of follow-up. Two authors independently evaluated studies for inclusion. The authors don't describe searching for unpublished studies. Ultimately, they included 18 studies with 1,539,904 patients, of whom 269,818 received some form of bariatric surgery: gastric bypass (n = 137,578, 51%), sleeve gastrectomy (n = 58,916, 22%), adjustable gastric band (n = 52,973, 20%), vertical banded gastroplasty (n = 6397, 2%), biliopancreatic diversion (n = 1002, 0.4%), or an alternative procedure or unspecified operation (n = 12,952, 5%). The median follow-up period was 59 months. The authors report that, overall, the quality of the studies was high. Eleven studies found a decreased association between surgery and all-cause mortality (odds ratio [OR] 0.62; 95% CI 0.55 - 0.69) with heterogeneity but no evidence for publication bias. Six studies found a decreased association between surgery and the subsequent development of type 2 diabetes (OR 0.39; 0.18 - 0.83), but also with statistical heterogeneity and no evidence for publication bias. Five studies found a lower risk of incident hypertension after surgery (0.36; 0.32 - 0.40) with no evidence for heterogeneity or publication bias. Only one study reported incident sleep apnea, which occurred in 1.1% of patients undergoing surgery compared with 2% of control patients. Five studies reported that incident ischemic heart disease was lower after surgery (0.46; 0.29 - 0.73), but with statistical heterogeneity and no evidence for publication bias. Two studies found no association between surgery and incident heart failure. Only one study reported venous thromboembolism, which occurred in 1.7% of patients undergoing surgery compared with 4.4% of control patients (hazard ratio 0.60; 0.43 - 0.84). Since this analysis excluded randomized trials, it is possible the magnitude of the lower risks of bad outcomes associated with bariatric surgery is inflated.