Background: Evidence from real-world studies have suggested a reduced rate of macrovascular complications following bariatric surgery. We undertook this meta-analysis to investigate the impact of bariatric surgery on macrovascular disease outcomes in severely obese type 2 diabetes mellitus (T2DM) patients.
Methods: An extensive literature search was performed in PubMed from inception until March 2020. All cohort studies assessing the association between bariatric surgery and macrovascular complications in severely obese T2DM patients were included. Two independent reviewers screened the articles, extracted data, and assessed the quality using the Newcastle-Ottawa Scale. The primary outcome was to assess the impact of bariatric surgery and the risk of macrovascular complications. Statistical analysis was performed using Review Manager 5.3.
Results: This meta-analysis comprised of five studies including 49,211 participants (75% female), of which 14,434 underwent bariatric surgery and 34,777 underwent usual care. Participants who underwent bariatric surgery had a significantly lower risk of macrovascular complications as compared to those with non-surgical interventions (RR: 0.50 [95% CI: 0.35-0.73], p = 0.0003). In the subgroup analysis, based on the geographical regions, studies conducted in the USA showed a higher reduction (RR: 0.41 [95% CI: 0.32-0.53], p < 0.00001) in macrovascular complications as compared to other parts of the world. The risk of all-cause mortality was also significantly lower in patients with bariatric surgery (RR 0.39 [95% CI: 0.30-0.50], p < 0.00001).
Conclusion: Bariatric surgery was associated with a 50% reduction in macrovascular complications along with 61% reduction in risk of all-cause mortality in morbidly obese T2DM patients.
Keywords: Bariatric surgery; Diabetes complications; Macrovascular complications; Meta-analysis; Obesity; T2DM.