Objective: Since its emergence in 2019, patients with pre-existing comorbidities such as diabetes mellitus (DM) have been reported to experience severe Coronavirus Disease (COVID-19). It has been associated with poorer outcomes among DM patients. This retrospective cross-sectional study aimed to determine the clinical-laboratory characteristics, glycemic events, and management among hospitalized patients with COVID-19 and DM.

Patients and Methods: We reviewed 244 medical records of patients with COVID-19 and DM admitted to Kenyatta National Hospital between March 2020 and March 2022. We extracted the patients’ demographics, clinical laboratory features, DM-related events, and management. Continuous variables were expressed as mean/standard deviation and categorical variables as numbers or percentages.

Results: The median age was 58 years, with males comprising 53% of the participants. Hypertension (61%) was the most common comorbidity. 78% had pre-existing DM, while 54 (22%) had newly diagnosed diabetes (NDDM). 82% of the patients had poor long-term glycemic control, with a mean glycated hemoglobin of 9%, and 65% had admission hyperglycemia. The most frequent symptoms were dyspnea (60%) and cough (62%), while the median admission SpO₂ was 84%. Elevated C-reactive protein (90%) and D-dimers (70%) with lymphopenia (32%) were among the laboratory observations. Diabetic ketoacidosis (DKA) occurred in 26% of patients, and 11% experienced hypoglycemia.

Conclusions: Hospitalized COVID-19 patients with DM had elevated random blood sugar (RBS) at admission, with poor overall glycemic control and elevated inflammatory markers. Glycemic events, including DKA/hyperosmolar hyperglycemic state (HHS), were common during hospitalization. Our findings underscore the importance of closely monitoring and managing glycemic control in patients with COVID-19 and diabetes.