Effect of SARS-CoV-2 Infection and Infection Severity on Longer-Term Glycemic Control and Weight in People With Type 2 Diabetes

Objective: To evaluate the association between COVID-19 infection and severity of infection on longer-term glycemic control and weight in persons with type 2 diabetes mellitus (T2D) in the U.S. Research Design and Methods: We conducted a retrospective cohort study using longitudinal electronic health record data of patients with COVID-19 infection from the National COVID Cohort Collaborative (N3C). Patients were ≥18 years old with an ICD-10 diagnosis of T2D and at least 1 HbA1c and weight measurement prior to and after an index date of their first COVID-19 diagnosis or negative SARS-CoV-2 test. We used propensity scores to identify a matched cohort balanced on demographic characteristics, comorbidities, and medications used to treat diabetes. The primary outcome was the post-index average hemoglobin A1c (HbA1c) and post-index average weight over a 1-year time period beginning 90 days after the index date among patients who did and did not have COVID-19 infection. Secondary outcomes were post-index average HbA1c and weight in patients who required hospitalization or mechanical ventilation. Results: There was no significant difference in the post-index average HbA1c or weight in patients who had COVID-19 infection compared to controls. Mechanical ventilation was associated with a decrease in average HbA1c after COVID-19 infection. Conclusions: In a multicenter cohort of patients in the U.S. with pre-existing T2D, there was no significant change in longer-term average HbA1c or weight among patients who had COVID-19 infection. For patients with COVID-19 infection, mechanical ventilation was associated with a decrease in HbA1c after infection.