Glycemic Control and Clinical Outcomes in U.S. Patients With COVID-19: Data From the National COVID Cohort Collaborative (N3C) Database

Abstract

<i>Objective: </i>The purpose of the study is to evaluate the relationship between HbA1c and severity of COVID-19 outcomes in patients with type 2 diabetes mellitus (T2D) with acute COVID-19 infection. <p><i>Research Design and Methods: </i>We conducted a retrospective study using observational data from the National COVID Cohort Collaborative (N3C), a longitudinal, multicenter US cohort of patients with COVID-19 infection. Patients were ≥18 years old with T2D and confirmed COVID-19 infection by either laboratory testing or diagnosis code. The primary outcome was 30-day mortality following the date of COVID-19 diagnosis. Secondary outcomes included need for invasive ventilation or ECMO, hospitalization within 7 days prior to or 30 days after COVID-19 diagnosis, and length of stay (LOS) for patients who were hospitalized.</p> <p><i>Results: </i>The study included 39,616 patients (50.9% female, 55.4% White, 26.4% Black or African American and 16.1% Hispanic or Latino, with mean [SD] age 62.1 [13.9] years and mean [SD] HbA1c 7.6% [2.0]. There was an increasing risk of hospitalization with incrementally higher HbA1c levels, but risk of death plateaued at HbA1c above 8% and risk of invasive ventilation or ECMO plateaued above 9%. There was no significant difference in LOS across HbA1c levels. </p> <p><i>Conclusions: </i>In a large, multicenter cohort of patients in the US with T2D and COVID-19 infection, risk of hospitalization increased with incrementally higher HbA1c levels. Risk of death and invasive ventilation also increased but plateaued at different levels of glycemic control.</p>