Independent Role of Severe Obesity as a Risk Factor for COVID-19 Hospitalization: A Spanish Population-Based Cohort Study.

OBJECTIVES: This study analyzed the association between severe obesity and coronavirus disease 2019 (COVID-19) hospitalization and severe disease. METHODS: The incidence of hospitalization for laboratory-confirmed COVID-19 was evaluated in a prospective population-based cohort of 433,995 persons aged 25 to 79 years in Spain during March and April of 2020. Persons with and without class 3 obesity were compared using Poisson regression to estimate the adjusted relative risk (aRR) from class 3 obesity of COVID-19 hospitalization and of severe disease (intensive care unit admission or death). Differences in the effect by age, sex, and chronic conditions were evaluated. RESULTS: Individuals with class 3 obesity had a higher risk of hospitalization (aRR = 2.20, 95% CI: 1.66-2.93) and developing severe COVID-19 (aRR = 2.30, 95% CI: 1.20-4.40). In people younger than 50 years, these effects were more pronounced (aRR = 5.02, 95% CI: 3.19-7.90 and aRR = 13.80, 95% CI: 3.11-61.17, respectively), whereas no significant effects were observed in those aged 65 to 79 years (aRR = 1.22, 95% CI: 0.70-2.12 and aRR = 1.42, 95% CI: 0.52-3.88, respectively). Sex and chronic conditions did not modify the effect of class 3 obesity in any of the outcomes. CONCLUSIONS: Severe obesity is a relevant risk factor for COVID-19 hospitalization and severity in young adults, having a magnitude similar to that of aging. Tackling the current obesity pandemic could alleviate the impact of chronic and infectious diseases.