ABSTRACT
Recent studies suggest COVID-19 infection has a detrimental effect on glycemic control in patients with diabetes in the acute care setting. However, there is limited information about the impact of COVID-19 on glycemic control in the months following infection. In this retrospective observational study, we examined the correlation between COVID-19 infection and glycemic control in adult patients with elevated A1c in a single health system (n=3,295). Patients were selected from a cohort of those age 18 years or older who were tested for COVID-19 between 3/1/2020 and 11/1/2020. COVID positive patients were identified through positive SARS-CoV-2 PCR or a COVID flag in the EMR. COVID negative patients were randomly selected in a 3:1 ratio from all patients who had a negative COVID test in the same week as each positive patient. Patients from this cohort were included if they had a baseline A1c ≥ 5.7% measured in the preceding six months and at least two weeks prior to their COVID positive (n=670) or COVID negative (n=2,625) test date, as well as an endpoint A1c ≥ 5.7% at least three months after this date. The study population was 54% female, 60% White, 20% Hispanic, and 13% Black with a mean BMI 32 ± 7.3 kg/m2, age 64.1 ± 13.6 yrs, and baseline A1c of 7.7± 1.6 %;81% of patients had a diagnosis of type 2 diabetes. In a linear regression model, COVID-19 infection was significantly associated with increased endpoint A1c (coefficient = 0.14, 95% CI [0.03 - 0.25], p = 0.01). Baseline A1c, male sex, and Hispanic ethnicity were also significantly associated with increased A1c, while age and median income based on zip code were associated with decreased A1c. In conclusion, prior COVID-19 infection appears to be associated with worse glycemic control at least 3 months post-infection compared to patients who did not contract COVID-19. Additional research is needed to determine if this association is present in other patient populations as well as the physiologic and socio-demographic causes for this finding.