Prognostic Value of Stress Hyperglycemia in Patients Admitted to Medical/Geriatric Departments for Acute Medical Illness

Introduction Hyperglycemia is common in patients admitted to Italian medical/geriatric units and is associated with a poorer outcome. We tested the significance of diabetes and stress-induced hyperglycemia in clinical outcome. Materials and Methods Three hundred seventy-eight consecutive patients with hyperglycemia at entry (≥ 126 mg/dl) (206 without known diabetes) were included, with a wide range of underlying diseases requiring hospital admission and independent of the presence of diabetes. Relative hyperglycemia was calculated as admission glucose divided by average glucose, estimated based of glycosylated hemoglobin. Values ≥ 1.20 were considered indicative of stress hyperglycemia (SHR). The association of SHR with outcome variables (all-cause complications, infections, non-infectious events, deaths) was tested by logistic regression analysis, adjusted for sex, BMI, age-adjusted comorbidities (Charlson index) and known diabetes. Results During hospital stay, one or more events were registered in 96 patients (25.4%); 44 patients died in hospital, and fatality rate was borderline higher in patients without diabetes (14.6% vs. 8.1% in diabetes; P = 0.052) and nearly three times higher in patients with stress hyperglycemia (15.0%) vs. those with SHR < 1.2 ( P = 0.005). Stress hyperglycemia—more common in the absence of diabetes (71% vs. 58%)—and age were the only independent prognostic factors for death. At multivariable analysis, the risks of death (OR 4.31, 95% CI 1.25–14.81), of all complications (OR 5.90, 95% CI 2.22–15.71) and of newly developed systemic infections (OR 5.67, 95% CI 1.61–19.92) were associated with stress hyperglycemia in subjects without diabetes, as was the risk in non-insulin-treated cases (OR 4.02, 95% CI 1.16–13.92; OR 5.47, 95% CI 2.21–13.52; OR 5.15, 95% CI 1.70–15.62, respectively). Conclusion The study confirms the prognostic value of stress-related hyperglycemia in patients requiring hospital admission to a geriatric/medical unit for a variety of acute medical conditions, contributing to adverse outcomes not limited to events commonly associated with hyperglycemia (e.g., infections).