A population-based cohort study of obesity, ethnicity and COVID-19 mortality in 12.6 million adults in England

Obesity and ethnicity are known risk factors for COVID-19 outcomes, but their combination has not been extensively examined. We investigate the association between body mass index (BMI) and COVID-19 mortality across different ethnic groups using linked national Census, electronic health records and mortality data for adults in England from the start of pandemic (January 2020) to December 2020. There were 30,067 (0.27%), 1,208 (0.29%), 1,831 (0.29%), 845 (0.18%) COVID-19 deaths in white, Black, South Asian and other ethnic minority groups, respectively. Here we show that BMI was more strongly associated with COVID-19 mortality in ethnic minority groups, resulting in an ethnic risk of COVID-19 mortality that was dependant on BMI. The estimated risk of COVID-19 mortality at a BMI of 40 kg/m(2) in white ethnicities was equivalent to the risk observed at a BMI of 30.1 kg/m(2), 27.0 kg/m(2), and 32.2 kg/m(2) in Black, South Asian and other ethnic minority groups, respectively. Obesity is a known risk factor for severe COVID-19 disease. Here, the authors use linked Census, electronic health records, and mortality data for 12.6 million adults in England and show that the association between COVID-19 mortality and body mass index is stronger in ethnic minority groups.

Automated summary

Obesity and ethnicity have been found to be risk factors for COVID-19 outcomes. This study reveals that the association between body mass index (BMI) and COVID-19 mortality is stronger in ethnic minority groups, suggesting that the ethnic risk of COVID-19 mortality depends on BMI.