Outcomes of hospitalized patients with type 2 diabetes and COVID-19: the impact of glycaemic control

Introduction: Diabetes mellitus is associated with poorer outcomes in patients with coronavirus disease (COVID-19). The mechanisms for this association are not fully elucidated. We aimed to evaluate the clinical characteristics and outcomes of hospitalized patients with type 2 diabetes (T2DM) and COVID-19, as well as the impact of blood glucose control on mortality. Material and Methods: In this retrospective study, we included 97 patients (38 with T2DM, 59 without diabetes). We compared demographic characteristics, comorbidities, admission findings and outcomes between patients with and without diabetes. To assess glycaemic control, individual derived time in range (70-180 mg/dL) was derived as the proportion of values within range. Derived time above range was calculated as the proportion of values above range. Results: The fatality rate of patients with diabetes was 36.8%. Among these patients, nonsurvivors presented with higher Pneumonia Severity Index score (159 +/- 36 vs 109 +/- 30, p=0.001), a higher N-terminal brain natriuretic peptide (5521 [4256-15280] vs 1541 [288-2349] pg/mL, p=0.047), a lower PaO2/FiO2 ratio (214 [181-259] vs 300 [248-347], p=0.033) and were more likely to have bilateral lung involvement at admission (78.6% vs 29.2%, p=0.013). Rates of acute kidney injury (85.7% vs 33.3%, p=0.003), acute heart failure (57.1% vs 25.0%, p=0.048) and secondary bacterial infection (64.3 vs 26.1%, p=0.022) were higher in deceased patients. Nonsurvivors had a lower derived time in range (38% vs 73%, p=0.020) and a higher derived time above range (62% vs 27%, p=0.020). Conclusion: A poorer glucose control assessed by lower derived time in range during hospitalization was associated with in-hospital death.