Admission glucose level was associated with increased short-term mortality and length-of-stay irrespective of diagnosis, treating medical specialty or concomitant laboratory values

BACKGROUND: Glucose is a routine emergency sample. General guidelines for inpatient hyperglycemia are scarce, except in myocardial infarction, stroke, and perioperative/ICU. Previous studies found admission glucose associated with increased mortality in specific conditions. Scandinavian data, and for general patients, are scarcer. We investigated admission glucose levels, 30-day mortality, and length-of-stay (LoS), in a Swedish hospital. METHODS: From 8146 emergency visits data regarding age, gender, dates of admission, discharge and death, diagnoses, admission p-glucose, s-sodium, s-potassium, b-hemoglobin, b-WBC and s-CRP, was collected, and for 6283 information regarding diagnosis of diabetes the previous 5 years. Visits were grouped in hypoglycemia (≤4.0), normoglycemia (>4.0-≤7.0), modest (>7.0-≤11.1) and severe hyperglycemia (>11.1) mmol/l. RESULTS: Short-term mortality was 1.5% in the normoglycemic, 2.6% in the hypoglycemic, 4.0-4.5% in modest and severe hyperglycemia, p < 0.001; Cox proportional hazard ratios (HR) for groups of patients without/with diabetes were 6.8; 1; 3.4; 4.4/7.3; 3.9; 4.0; 2.1 compared to the normoglycemic without diabetes (p 0.0001-0.05); adjusted for age, and concurrent levels of sodium, potassium, Hb, WBC and CRP 1.51 (1.07-2.1, p 0.02) with modest hyperglycemia, and 1.08 (0.60-1.95, p 0.80) in severe hyperglycemia. Mean LoS was 1.2 and 1.7 days longer with modest and severe hyperglycemia. CONCLUSIONS: Short-term mortality increased substantially with admission hypo- and hyperglycemia for patients both with and without diabetes, irrespective of treating medical specialty, main discharge diagnosis, or concurrent laboratory values. Patients with diabetes (16%) were older, with higher glucose levels at admission, and with a different pattern of the association of admission glucose and mortality.