Obesity or increased body mass index and the risk of severe outcomes in patients with COVID-19

To assess the effect of obesity or a high body mass index (BMI) on the risk of severe outcomes in patients with coronavirus disease 2019 (COVID-19).Studies on the relationship between BMI or obesity and COVID-19 since December 2019. The odds ratio (OR) and weighted mean difference (WMD) with their 95% confidence intervals (CIs) were used to assess the effect size.BMI was significantly increased in COVID-19 patients with severe illness (WMD: 1.18; 95% CI: 0.42-1.93), who were admitted to an intensive care unit (ICU) (WMD: 1.46; 95% CI: 0.96-1.97), who required invasive mechanical ventilation (IMV) (WMD: 2.70, 95% CI: 1.05-4.35) and who died (WMD: 0.91, 95% CI: 0.02-1.80). In Western countries, obesity (BMI of ≥30 kg/m2) increased the risk of hospitalization (OR: 2.08; 95% CI: 1.22-3.54), admission to an ICU (OR: 1.54; 95% CI: 1.29-1.84), need for IMV (OR: 1.73, 95% CI: 1.38-2.17), and mortality (OR: 1.43; 95% CI: 1.17-1.74) of patients with COVID-19. In the Asian population, obesity (BMI of ≥28 kg/m2) increased the risk of severe illness (OR: 3.14; 95% CI: 1.83-5.38). Compared with patients with COVID-19 and a BMI of <25 kg/m2, those with a BMI of 25-30 kg/m2 and ≥30 kg/m2 had a higher risk of need for IMV (OR: 2.19, 95% CI: 1.30-3.69 and OR: 3.04; 95% CI: 1.76-5.28, respectively). The risk of ICU admission in patients with COVID-19 and a BMI of ≥30 kg/m2 was significantly higher than in those with a BMI of 25-30 kg/m2 (OR: 1.49; 95% CI: 1.00-2.21).As BMI increased, the risks of hospitalization, ICU admission, and need for IMV increased, especially in COVID-19 patients with obesity.This systematic review and meta-analysis does not require an ethics approval as it does not collect any primary data from patients.