Glucose-lowering drugs and outcome from COVID-19 among patients with type 2 diabetes mellitus: a population-wide analysis in Hong Kong

ObjectivesTo investigate the association between baseline use of glucose-lowering drugs and serious clinical outcome among patients with type 2 diabetes.DesignTerritory-wide retrospective cohort of confirmed cases of COVID-19 between January 2020 and February 2021.SettingAll public health facilities in Hong Kong.Participants1220 patients with diabetes who were admitted for confirmed COVID-19.Primary and secondary outcome measuresComposite clinical endpoint of intensive care unit admission, requirement of invasive mechanical ventilation and/or in-hospital death.ResultsIn this cohort (median age 65.3 years, 54.3% men), 737 (60.4%) patients were treated with metformin, 385 (31.6%) with sulphonylureas, 199 (16.3%) with dipeptidyl peptidase-4 (DPP-4) inhibitors and 273 (22.4%) with insulin prior to admission. In multivariate Cox regression, use of metformin and DPP-4 inhibitors was associated with reduced incidence of the composite endpoint relative to non-use, with respective HRs of 0.51 (95% CI 0.34 to 0.77, p=0.001) and 0.46 (95% CI 0.29 to 0.71, p