Association of Obesity with COVID-19 Severity and Mortality: A Systemic Review and Meta-Regression

Objective: To estimate the association of obesity with severity (defined as use of invasive mechanical ventilation or intensive care unit admission) and all-cause mortality in coronavirus disease 2019 (COVID-19) patients. Patients and Methods: A systematic search was conducted from inception of COVID-19 pandemic through January 31st, 2021 for full-length articles focusing on the association of increased BMI/ Obesity and outcome in COVID-19 patients with help of various databases including Medline (PubMed), Embase, Science Web, and Cochrane Central Controlled Trials Registry. Preprint servers such as BioRxiv, MedRxiv, ChemRxiv, and SSRN were also scanned. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used for study selection and data extraction. The severity in hospitalized COVID-19 patients, such as requirement of invasive mechanical ventilation and intensive care unit admission with high BMI/ Obesity was the chief outcome. While all-cause mortality in COVID-19 hospitalized patients with high BMI/ Obesity was the secondary outcome. Results: A total of 576,784 patients from 100 studies were included in this meta-analysis. Being obese was associated with increased risk of severe disease (RR=1.46, 95% CI 1.34-1.60, p<0.001, I2 = 92 %). Similarly, high mortality was observed in obese patients with COVID-19 disease (RR=1.12, 95% CI 1.06-1.19, p<0.001, I2 = 88%). In a multivariate meta-regression on severity outcome, the covariate of female gender, pulmonary disease, diabetes, older age, cardiovascular diseases, and hypertension was found to be significant and explained R2= 50% of the between-study heterogeneity for severity. Similarly, for mortality outcome, covariate of female gender, proportion of pulmonary disease, diabetes, hypertension, and cardiovascular diseases were significant, these covariates collectively explained R2=53% of the between-study variability for mortality. Conclusions: Our findings suggest that obesity is significantly associated with increased severity and higher mortality among COVID-19 patients. Therefore, the inclusion of obesity or its surrogate body mass index in prognostic scores and streamlining the management strategy and treatment guidelines to account for the impact of obesity in patient care management is recommended.