Predictive Value of the CURB-65, MuLBSTA, Pneumonia Severity Index Scores and Laboratory Parameters for In-Hospital Mortality in Patients with Diabetes Mellitus and COVID-19 Infection

Background/Objectives: Several risk factors have been identified as being involved in the progression of COVID-19 over time. Among these, age, comorbidities, and various laboratory parameters have been reported. Diabetes mellitus is one of the most common comorbidities found among patients diagnosed with SARS-CoV-2 infection. Glucose metabolism dysfunction can exacerbate pre-existing diabetes or even induce diabetes mellitus. The purpose of this study is to assess the accuracy of the CURB-65, PSI, MuLBSTA severity scores and laboratory parameters in patients with diabetes mellitus diagnosed with COVID-19. Methods: We conducted a retrospective study involving patients with diabetes mellitus diagnosed with SARS-CoV-2 infection, performed between June 2023 and December 2024. Results: We analyzed 73 patients with pre-existing diabetes who were diagnosed with COVID-19. There were 56.16% men, living mostly in urban areas, with a median hospital stay of 9.38 days. Elevated levels of LDH (367.50, p = 0.002), CRP (133.90, p = 0.012), ferritin (724.25, p = 0.012), ESR (55.00, p = 0.014), D-dimers (2455.04, p = 0.004), white blood cells (12.76, p = 0.007) and the neutrophil-to-lymphocyte ratio (15.86, p = 0.021) were recorded in the group of deceased patients. Significantly elevated values were recorded for all three severity scores, the AUC for CURB-65 was 0.69, PSI 0.81 and MuLBSTA 0.86. Conclusions: Severity scores showed robust prognostic value in predicting mortality among patients with diabetes mellitus and COVID-19, emphasizing their relevance as clinically applicable tools for risk stratification and outcome assessment.