OBJECTIVE: Obesity has been shown to be associated with adverse outcomes in viral infections such as influenza, but previous studies on coronavirus disease 2019 (COVID-19) had mixed results. The aim of this systematic review is to investigate the relationship between COVID-19 and obesity. METHODS: We performed a systematic review and meta-analysis. A literature search of MEDLINE, EMBASE, Scopus, Web of Science, CENTRAL, OpenGrey and preprint servers medRxiv and bioRxiv was performed, with no restriction on language or date of publication. Primary outcomes of this study were intensive care unit (ICU) admission or critical disease, severe disease and mortality. Secondary outcome was a positive COVID-19 test. Meta-analysis was performed using OpenMeta-Analyst software, and heterogeneity was tested using Cochran's Q test and I2 statistic. The study protocol was registered on PROSPERO (CRD42020184953). RESULTS: A total of 1,493 articles were identified and 61 studies on 270,241 patients were included. The pooled prevalence of obesity was 27.6% (95% confidence interval [CI] 22.0-33.2) in hospitalised patients. Obesity was not significantly associated with increased ICU admission or critical illness (odds ratio [OR] 1.25, 95% CI 0.99-1.58, P=0.062, I(2) =31.0) but was significantly associated with more severe disease (OR 3.13, 95% CI 1.41-6.92, P=0.005, I(2) =82.6), mortality (OR 1.36, 95% CI 1.09-1.69, P=0.006, I(2)=88.5) and a positive COVID-19 test (OR 1.50, 95% CI 1.25-1.81, P<0.001). CONCLUSION: Obesity increased the risk of severe disease, mortality and infection with COVID-19. Higher body mass index was associated with ICU admission and critical disease. Patients who are obese may be more susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and infected patients should be monitored closely for adverse outcomes.
All age groups Risk group Risk factor COVID-19