The effect of diabetes mellitus on disease prognosis in COVID-19 patients

Background: In this study, we aimed to evaluate and compare the clinical characteristics, laboratory findings, and outcomes of hospitalized patients with and without diabetes along with poorly vs. well-controlled diabetes. Methods: A total of 341 hospitalized patients with COVID-19 confirmed by RT-PCR and/or chest imaging suggestive of COVID-19 infection were retrospectively included in this study. The patients were divided into 2 groups as diabetic (n = 120) and non-diabetic (n = 221). Demographic data, symptoms, comorbidities, and laboratory values were recorded. The patients were classified according to the clinical stages defined by guidance of the WHO for COVID-19. The percentage of patients with severe disease was higher in diabetic group (n = 57) 47.5% compared to non-diabetic group (n = 61) 27.8% (p = 0.001). The percentage of patients requiring oxygen therapy was significantly higher in 61 (51.2%) diabetic group than non-diabetic group 65 (29.4%) (p = 0.001). The median duration of hospitalization in the diabetic group was 8 days [IQR 6–11.5] that was significantly higher than the non-diabetic group as 7 days [IQR 5–10] (p = 0.009). The median duration of hospitalization in poorly controlled diabetic group was 9 days [IQR 6.00–16.00] that was significantly higher than well-controlled diabetic group 8 days [IQR 6.00–11.00] (p = 0.006). Results: Patients with diabetes were more susceptible to COVID-19 infection and the infection was more severe in patients with diabetes compared to patients without diabetes. However, the mortality rate was similar between diabetic and non-diabetic group. Diabetic COVID-19 patients without other comorbidities were not prone to severe infection. Conclusion: Patients with diabetes and comorbidities, apart from the glycemic control, should receive intensive monitoring and disease management.