Comparative Incidence of Diabetes Following Hospital Admission for COVID-19 and Pneumonia: A Cohort Study

Abstract

OBJECTIVE The incidence of diabetes may be elevated following coronavirus disease 2019 (COVID-19), but it is unclear whether this is specific to severe acute respiratory syndrome coronavirus 2 infection, associated with shared risk factors for severe COVID-19 and diabetes, and/or a generic risk following illness. RESEARCH DESIGN AND METHODS People admitted to the hospital for COVID-19 and/or pneumonia between 1 April 2020 and 31 August 2020 in England were linked with the National Diabetes Audit to identify incident diabetes after discharge up to 31 March 2021. Compar-ator cohorts admitted with pneumonia over the same dates in 2017, 2018, and 2019 were followed until 31 March 2018, 31 March 2019, and 31 March 2020, re-spectively. Poisson regression models were used to calculate adjusted diabetes incidence rates. RESULTS Using the cohort of people discharged from the hospital following a diagnosis of COVID-19 without pneumonia in 2020 as the standard population (incidence rate 16.4 [95% CI 12.8–20.7] per 1,000 person-years), adjusting for age, sex, ethnicity, and deprivation, gave incidence rates of 19.0 (95% CI 13.8–25.6) and 16.6 (95% CI 13.3–20.4) per 1,000 person-years for those admitted for COVID-19 with pneumonia and pneumonia without COVID-19, respectively, in 2020. These rates are not significantly different from those found after hospital admission for pneumonia in 2019, 2018, and 2017, at 13.7 (95% CI 10.8–17.3), 13.8 (95% CI 10.9–17.4), and 14.2 (95% CI 10.9–18.3) per 1,000 person-years, respectively. CONCLUSIONS Our data do not support a clear impact of COVID-19 on the incidence of diabetes compared with risks in several comparator groups, including contemporaneously assessed risks in people hospitalized with pneumonia.