Effect of Baseline HbA1c and Inpatient Glycemic Control on Mortality and Organ Dysfunction among Patients with Diabetes Mellitus Hospitalized for COVID-19: A Multicenter Retrospective Cohort Study

Background: Individuals with diabetes mellitus (DM) show increased susceptibility to COVID-19 infection with higher risk for severe disease and mortality. Objectives: We investigated whether glycemic-related factors may affect the outcomes of patients with DM hospitalized due to COVID-19. Methodology: This is a multicenter retrospective cohort study under the initiative of the Philippine College of Endocrinology, Diabetes, and Metabolism involving eight training hospitals in the Philippines from January 2021 to January 2022. Patients with DM hospitalized due to COVID-19 were included. Univariable and multivariable analyses were done to determine whether baseline glycemic control based on glycosylated hemoglobin (HbA1c) and inpatient glycemic control based on capillary blood glucose are associated with composite poor clinical outcome of mortality and end-organ dysfunction. Conclusion: COVID-19 severity had the greatest impact and is the only variable with a statistically significant association with composite poor clinical outcomes after adjusting for all other variables. Poor glycemic control on admission and during hospitalization were associated with more severe COVID-19, although they did not directly impact clinical outcomes. Measures to optimize glycemic control both in the long term and during hospitalization should be considered to prevent severe COVID-19, hence improving clinical outcomes and survival.