To explore the association between body mass index (BMI) and clinico-neurological outcomes in a large cohort of patients with coronavirus disease 2019 (COVID-19).

This is a secondary analysis of a 37-site, nationwide, multicenter, retrospective cohort study that investigated the clinical and neurological outcomes of adult patients with confirmed COVID-19 admitted from February to December 15, 2020. 

We analyzed 4,463 patients with BMI and outcome data. A total of 790 (17.7%) and 710 (15.9%) had the primary outcome of in-hospital mortality and need for invasive mechanical ventilation (IMV), respectively. There was no significant association between WHO BMI groups and these outcomes. Using Asia-Pacific cutoffs showed a significant association between obesity and in-hospital mortality risk (P = 0.012). Being underweight was an independent predictor of prolonged IMV requirement regardless of BMI criteria used (P < 0.01). Obesity correlated with the need for intensive care unit admission using Asia-Pacific cutoffs (P = 0.029). There was a significant association between any BMI abnormality and odds of severe/critical COVID-19 (P < 0.05). Obese patients with concomitant acute neurological presentation/diagnosis during their COVID-19 admission were shown to have lower odds of neurologic recovery (P < 0.05). 

We found BMI abnormalities to be associated with several adverse clinical and neurologic outcomes, although such associations may be more evident with the use of race-specific BMI criteria.