Is BMI higher in younger patients with COVID-19? Association between BMI and COVID-19 hospitalization by age.

OBJECTIVE: Obesity has been found to be a risk factor for hospitalization with COVID-19. We were interested in understanding whether patients hospitalized with COVID-19 differed in BMI at older versus younger ages, and if trends were independent of diabetes and hypertension.

METHODS: We performed a cross-sectional analysis of patients hospitalized with moderate to severe COVID-19 at Northwestern Memorial Hospital from March 19th , 2020 until April 4th , 2020. We compared patients hospitalized with COVID-19 above and below the age of 50, and to those hospitalized without COVID-19.

RESULTS: We found patients younger than 50 years of age hospitalized with COVID-19 without diabetes or hypertension had mean BMI greater than those older than 50 years of age, with BMI 43.1 (95%CI 34.5 - 51.7) kg/m2 vs 30.1 (95%CI 27.7 - 32.5) kg/m2 (p=0.02). Furthermore, BMI appears to inversely correlate with increasing age amongst patients hospitalized with COVID-19. We did not detect the same difference or trend for patients hospitalized without COVID-19.

CONCLUSION: We found younger patients (age <50 years) with COVID-19 had higher mean BMI than older patients with COVID-19, with and without diabetes and hypertension. This trend did not exist in patients without COVID-19 hospitalized during the same time-period.