Body mass index-mortality relationship in severe hypoglycemic patients with type 2 diabetes.

BACKGROUND: Hypoglycemia is associated with a higher risk of death. This study analyzed various body mass index (BMI) categories and mortalities of severe hypoglycemic patients with type 2 diabetes mellitus (DM) in a hospital emergency department.

METHODS: The study included 566 adults with type 2 diabetes who were admitted to 1 medical center in Taiwan between 2008 and 2009 with a diagnosis of severe hypoglycemia. Mortality data, demographics, clinical characteristics and the Charlson's Comorbidity Index were obtained from the electronic medical records. Patients were stratified into 4 study groups as determined by the National Institute of Health (NIH) and World Health Organization classification for BMI, and the demographics were compared using the analysis of variance and χ² test. Kaplan-Meier's analysis and the Cox proportional-hazards regression model were used for mortality, and adjusted hazard ratios were adjusted for each BMI category among participants.

RESULTS: After controlling for other possible confounding variables, BMI <18.5 kg/m² was independently associated with low survival rates in the Cox regression analysis of the entire cohort of type 2 DM patients who encountered a hypoglycemic event. Compared to patients with normal BMI, the mortality risk was higher (adjusted hazard ratios = 4.9; 95% confidence interval [CI] = 2.4-9.9) in underweight patients. Infection-related causes of death were observed in 101 cases (69.2%) and were the leading cause of death.

CONCLUSIONS: An independent association was observed between BMI less than 18.5 kg/m² and mortality among type 2 DM patient with severe hypoglycemic episode. Deaths were predominantly infection related.