ABSTRACT
Background and Aims: Obesity is an established risk factor for severe coronavirus disease 2019 (COVID-19) but the contribution of overweight and/or diabetes remain unclear. In a multi-center international study, we investigated if overweight, obesity and diabetes were independently associated with COVID-19 severity, and whether the body mass index (BMI)-associated risk was increased among those with diabetes. Methods: We retrospectively extracted data from health care records and regional databases of hospitalized adult patients with COVID-19 from 18 sites in 11 countries. We used standardized definitions and analyses to generate site-specific estimates, modelling the odds of each outcome (supplemental oxygen/non-invasive ventilation, invasive mechanical ventilation, and in-hospital mortality) by BMI category (reference, overweight, obese) adjusting for age, sex, and pre-specified co-morbidities. Subgroup analysis was performed on patients with pre-existing diabetes. Site-specific estimates were combined in a meta-analysis. Results: Among 7244 patients (65·6% overweight/obese), those with overweight were more likely to require oxygen/non-invasive ventilation (random effects adjusted odds ratio [aOR] 1.44 [95% CI 1·15-1.80]) and invasive mechanical ventilation (aOR 1.22 [CI 1.03-1.46]). There was no association between overweight and in-hospital mortality (aOR 0.88 [CI 0.74-1.04]). Similar effects were observed in patients with obesity or diabetes. In the subgroup analysis, the aOR for any outcome was not additionally increased in those with diabetes and overweight or obesity. Conclusions: In adults hospitalized with COVID-19, overweight as well as obesity and diabetes increased the odds of respiratory support but not mortality. In patients with diabetes, the odds of severe COVID-19 were not increased above the BMI-associated risk.