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

OBJECTIVE The purpose of the study is to evaluate the relationship between HbA(1c) and severity of coronavirus disease 2019 (COVID-19) outcomes in patients with type 2 diabetes (T2D) with acute COVID-19 infection. RESEARCH DESIGN AND METHODS We conducted a retrospective study using observational data from the National COVID Cohort Collaborative (N3C), a longitudinal, multicenter U.S. cohort of patients with COVID-19 infection. Patients were >= 18 years old with T2D and confirmed COVID-19 infection by 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 extracorporeal membrane oxygenation (ECMO), hospitalization within 7 days before or 30 days after COVID-19 diagnosis, and length of stay (LOS) for patients who were hospitalized. RESULTS 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 HbA(1c) 7.6% +/- 2.0). There was an increasing risk of hospitalization with incrementally higher HbA(1c) levels, but risk of death plateaued at HbA(1c) >8%, and risk of invasive ventilation or ECMO plateaued >9%. There was no significant difference in LOS across HbA(1c) levels. CONCLUSIONS In a large, multicenter cohort of patients in the U.S. with T2D and COVID-19 infection, risk of hospitalization increased with incrementally higher HbA(1c) levels. Risk of death and invasive ventilation also increased but plateaued at different levels of glycemic control.

Automated summary

In a large multicenter cohort of T2D patients with COVID-19 infection in the US, a higher HbA(1c) level was found to be associated with an increased risk of hospitalization. The risk of death and invasive ventilation also increased but plateaued at different levels of glycemic control. There was no significant difference in length of stay across different HbA(1c) levels.