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Obesity during the COVID-19 pandemic: both cause of high risk and potential effect of lockdown? A population-based electronic health record study

Research output: Contribution to journalArticlepeer-review

M. Katsoulis, L. Pasea, A. G. Lai, R. J.B. Dobson, S. Denaxas, H. Hemingway, A. Banerjee

Original languageEnglish
Pages (from-to)41-47
Number of pages7
JournalPublic Health
PublishedFeb 2021

Bibliographical note

Publisher Copyright: © 2020 The Royal Society for Public Health Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors


Objectives: Obesity is a modifiable risk factor for coronavirus disease 2019 (COVID-19)–related mortality. We estimated excess mortality in obesity, both ‘direct’, through infection, and ‘indirect’, through changes in health care, and also due to potential increasing obesity during lockdown. Study design: The study design of this study is a retrospective cohort study and causal inference methods. Methods: In population-based electronic health records for 1,958,638 individuals in England, we estimated 1-year mortality risk (‘direct’ and ‘indirect’ effects) for obese individuals, incorporating (i) pre-COVID-19 risk by age, sex and comorbidities, (ii) population infection rate and (iii) relative impact on mortality (relative risk [RR]: 1.2, 1.5, 2.0 and 3.0). Using causal inference models, we estimated impact of change in body mass index (BMI) and physical activity during 3-month lockdown on 1-year incidence for high-risk conditions (cardiovascular diseases, diabetes, chronic obstructive pulmonary disease and chronic kidney disease), accounting for confounders. Results: For severely obese individuals (3.5% at baseline), at 10% population infection rate, we estimated direct impact of 240 and 479 excess deaths in England at RR 1.5 and 2.0, respectively, and indirect effect of 383–767 excess deaths, assuming 40% and 80% will be affected at RR = 1.2. Owing to BMI change during the lockdown, we estimated that 97,755 (5.4%: normal weight to overweight, 5.0%: overweight to obese and 1.3%: obese to severely obese) to 434,104 individuals (15%: normal weight to overweight, 15%: overweight to obese and 6%: obese to severely obese) would be at higher risk for COVID-19 over one year. Conclusions: Prevention of obesity and promotion of physical activity are at least as important as physical isolation of severely obese individuals during the pandemic.

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