Risk of stroke after bariatric surgery: a systematic review, meta-analysis and meta-regression

Abstract Background Obesity is a major global health challenge, strongly associated with diabetes, hypertension, and cardiovascular disease, all of which increase stroke risk. Bariatric surgery is among the most effective treatments for severe obesity, leading to significant and sustained weight loss and improvements in metabolic health. However, its long-term impact on cerebrovascular outcomes remains unclear. Methods We searched multiple databases for cohort studies that compared stroke incidence in patients undergoing bariatric surgery. Hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled using a random-effects model. Heterogeneity was quantified using the I 2 statistic. Meta-regression was performed to explore the effects of age, BMI and follow-up duration. Results Eighteen studies comprising 2,125,741 patients were included. Pooled analysis of 16 studies (975,351 patients) showed that bariatric surgery was associated with a 29% lower risk of stroke compared with non-surgical care (HR = 0.71, 95% CI 0.65–0.77, p < 0.0001). Heterogeneity was moderate (I 2 = 60.6%) but resolved in sensitivity analyses. No significant publication bias was detected and meta-regression showed no effect modification by age, BMI or follow-up duration. Conclusion This meta-analysis provided a robust evidence that bariatric surgery is associated with a significantly reduced risk of stroke in patients with obesity. The findings highlight bariatric surgery not only as an effective intervention for weight loss and metabolic improvement but also as a meaningful strategy for long-term cerebrovascular risk reduction. Incorporating bariatric surgery into comprehensive cardiovascular and stroke prevention strategies could have substantial public health impact.