Impact of Prior Bariatric Surgery on Mortality in COVID-19 Patients: a Comprehensive Meta-analysis

Obesity has been linked to immunosuppressive effects and increased susceptibility to respiratory infections, including COVID-19. Bariatric surgery (BS) has demonstrated promising results in enhancing a variety of clinical outcomes in obese patients. The purpose of this meta-analysis is to evaluate the effect of BS on COVID-19 outcomes, specifically all-cause mortality. A thorough literature search was conducted in electronic databases to identify pertinent studies through November 2022. Inclusion criteria included retrospective cohort studies that investigated the association between BS and COVID-19 mortality. Data extraction and quality assessment were carried out in accordance with established protocols. A random-effects model was used to calculate the odds ratio (OR) and 95% confidence intervals (CIs). Using I 2 statistics, heterogeneity was evaluated, and publication bias was assessed using funnel plots. Eight retrospective studies involving a total cohort of 409,665 patients met the quantitative analysis eligibility criteria. In the crude unmatched analysis, the overall mortality rate among patients with prior BS was significantly lower than among those without BS (OR 0.52; 95% CI [0.43, 0.62]; p = 0.03; I 2 = 53.66%). After adjusting for comorbidities, the matched analysis yielded comparable results (OR 0.42, 95% CI [0.25, 0.72], p = 0.14, I 2 = 41.88%). Comparing the BS group to the non-BS group, subgroup analyses by country (the USA and Europe) showed that the BS group had a mortality risk that was nearly 50% lower. The funnel plot indicated that there was no publication bias, and the sensitivity analysis revealed balanced results when each study was excluded. This meta-analysis suggests that a history of BS is associated with a decreased risk of deaths from all causes in COVID-19 patients. These results highlight the prospective benefits of BS in mitigating adverse outcomes in obese COVID-19 patients. To investigate the underlying mechanisms and potential confounders of this association, additional research is required.