Prediction of 90-day mortality in patients without diabetes by severe hypoglycemia: blood glucose level as a novel marker of severity of underlying disease

Abstract

Aim: The present study examined the clinical conditions and predictors of death in non-diabetic patients with pre-hospital severe hypoglycemia. Materials and methods: From January 2006 to March 2012, we retrospectively reviewed the medical records to assess the patients with pre-hospital severe hypoglycemia at a national center in Japan. Severe hypoglycemia was defined as the presence of any hypoglycemic symptoms requiring the medical assistance of another person. The patients were followed up for 90 days after the severe hypoglycemia episode. Results: A total of 59,602 consecutive cases that visited the emergency room were screened, and 530 patients with severe hypoglycemia were included in the subsequent analysis. The mean blood glucose levels in the non-diabetes (non-DM, n = 163) and diabetes (DM, n = 367) groups were 42.9 and 33.7 mg/dL, respectively. The incidence of extremely abnormal QT prolongation (corrected QT interval ≥0.50 s) was high in both groups [22.1 vs. 14.7 % (P = 0.11)]. Mortalities within 90 days after severe hypoglycemia were significantly higher in the non-DM group than in the DM group [20.3 vs. 1.6 % (P < 0.001)]. In addition to patient age, preexisting advanced liver disease and cancer, and the coexistence of sepsis, a blood glucose level of <40 mg/dL was identified as a strong predictor of death in the non-DM group using multivariate Cox proportional hazards models (hazard ratio 3.75; 95 % confidence interval 1.52–9.27; P = 0.004). Conclusions: Death in non-diabetic patients with severe hypoglycemia was independently associated not only with age, advanced liver disease, cancer, and sepsis, but also with the blood glucose level upon arrival.