Glycosylated Hemoglobin as an Independent Prognostic Marker in COVID-19 Patients With Diabetes Mellitus

Objective The main objective of this study is to analyze the severity of coronavirus disease 2019 (COVID-19) among patients with diabetes mellitus using glycosylated hemoglobin (HbA1c) as a prognostic marker in predicting the outcome among these individuals. Methods This was a retrospective, observational study conducted in a tertiary care center during the first and second waves of COVID-19 in Salem, Tamil Nadu, for a period of one year (September 2020-September 2021). Numerous variables, including socio-demographic data, vitals, laboratory and radiological investigations, and end variables like mortality and morbidity due to COVID-19, were studied. Results Out of the 754 people admitted, 253 were diabetic, among which only 65 individuals fulfilled the criteria for participation. Among the 65 patients in the study, 21 had mild disease, 28 had moderate disease, among whom, two patients had HbA1c less than 7, 10 had between 7 and 8, 11 had between 8 and 10, and five had above 10, and 16 had severe disease, among whom one patient had HbA1c less than 7, 4 between 7 and 8, seven between 8 and 10, and four above 10. This was statistically significant (0.005). Conclusion The incidence of mortality was high among patients with prolonged uncontrolled diabetes mellitus with high HbA1c and among patients presenting diabetic complications like diabetic ketoacidosis (DKA), euglycemic ketoacidosis, and hyperglycemic hyperosmolar syndrome (HHS).