Abstract
BACKGROUND: Type 2 diabetes mellitus (T2DM) patients infected with coronavirus disease 2019 (COVID-19) are at a higher risk of experiencing poorer prognoses and increased mortality. Glucocorticoids are recommended for the treatment of COVID-19, especially in patients with severe disease. However, the efficacy and safety of glucocorticoids in COVID-19 patients with T2DM remain a subject of debate. METHODS: We conducted a multicenter, retrospective cohort study of hospitalized patients with T2DM and confirmed COVID-19 admitted between November 1, 2022 and January 31, 2023. Data on clinical manifestations, treatment strategies, and clinical outcomes were systematically collected and rigorously evaluated. RESULTS: A total of 624 COVID-19 patients with T2DM were enrolled, comprising 259 patients with severe disease and 365 with non-severe disease. Compared with the non-severe group, the severe group demonstrated significantly elevated levels of inflammatory markers and more extensive multi-organ dysfunction. Multivariate logistic regression identified advanced age, male sex, cerebrovascular disease history, and poor fasting glucose control as independent predictors of progression to severe illness. Among patients with severe disease, glucocorticoid therapy was significantly associated with reduced in-hospital mortality and a shorter median length of stay; this association remained robust after adjustment for baseline glycemic status. Six-month post-discharge follow-up revealed no significant between-group differences in the incidence of long COVID-19 or interstitial pneumonia; however, among patients in non-severe group, those who received glucocorticoids exhibited a higher incidence of long COVID-19. CONCLUSION: Glucose control is of particular importance for COVID-19 patients with T2DM. In mild or moderate cases, systemic use of glucocorticoid therapy should be strictly evaluated. In severe or critical cases, cautious, appropriate use of glucocorticoids may be associated with improved short-term prognosis and reduced mortality.