The obesity paradox in Japanese COVID-19 patients.

Purpose: To investigate the effect of obesity on mortality and invasive respiratory care (IRC) in patients with COVID-19. Methods: We studied 1,105 patients for 34 months and collected data. The primary outcome was all-cause death at 29 days. The secondary outcome was IRC indicated by a pulse oximetry rate below 93% at a mask oxygenation rate of 5 L/min or more. Results: Age- and sex-adjusted multivariate regression analysis for 29-day deaths showed the significance of body mass index (BMI) > 19.6 kg/m2 (odds ratio 0.117, 95% confidence interval 0.052-0.265, P<0.001). The graphs with BMI in the abscissa showed, within a BMI between 11 and 25 kg/m2, a decreasing pattern for mortality and IRC rate, and no increase in overweight. Conclusion: In Japanese COVID-19 patients, the risk of mortality and the IRC rate decreased in underweight patients and remained low in overweight patients, suggesting the importance of the obesity paradox.