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

Thomas Yates,Vahé Nafilyan,Yogini Chudasama,Kamlesh Khunti,Evgeny Mirkes,Francesco Zaccardi,Clare Gillies,Annabel Summerfield,Melanie J Davies,Nazrul Islam,Claire Lawson,Amitava Banerjee,Cameron Razieh

doi:10.1038/s41467-022-28248-1

Abstract

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/m2 in white ethnicities was equivalent to the risk observed at a BMI of 30.1 kg/m2, 27.0 kg/m2, and 32.2 kg/m2 in Black, South Asian and other ethnic minority groups, respectively.

Highlights

Obesity and ethnicity are known risk factors for COVID-19 outcomes, but their combination has not been extensively examined
The full descriptive profile of the cohort stratified by ethnicity is displayed in Supplementary Table 1; characteristics further stratified by ethnicity and body mass index (BMI) category are presented in Supplementary Data 1 and 2
In 12.6 million adults with linked Census, electronic health care records and mortality data, BMI was associated with COVID-19 mortality amongst all ethnic groups, but with a stronger association in ethnic minority groups

Summary

Introduction

Obesity and ethnicity are known risk factors for COVID-19 outcomes, but their combination has not been extensively examined. An early analysis of 5,623 community and in-hospital test results suggested the potential importance of this by showing the risk of SARS-CoV-2 positivity was not different between ethnic groups at low BMI, but was over twofold higher in ethnic minority groups compared to white ethnicities at high BMI11. This has not been explored in larger representative community cohorts or with COVID-19 outcomes. The aim of this study was to use linked national Census, electronic health care records and mortality datasets to investigate the interaction between BMI and ethnicity in the risk of COVID19 mortality, quantify how the difference in risk between ethnic groups varies by BMI, and generate risk equivalency at established BMI thresholds for class I, II, and III obesity

Objectives

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Results

Conclusion