Mortality in hospitalized patients with hypoglycemia and severe hyperglycemia.

BACKGROUND: We designed a study to determine the incidence, cause, and implications of hypoglycemia (< or = 2.7 mmol/L, 49 mg/dL) and severe hyperglycemia (> or = 22.2 mmol/L, 400 mg/dL) in in-patients at an urban tertiary medical center. METHODS: A daily computer search of the Laboratory Information System identified all hospitalized patients with hypoglycemia and severe hyperglycemia during a 49-day period. Chart review was used to assess demographic information, risk factors, and epidemiologic variables. The eventual outcome of the hospitalization was obtained by follow-up. RESULTS: The incidence of hypoglycemia was 1.5%, and of hyperglycemia, 1.9%. Seventy-six percent of the hypoglycemic patients and 16% of the hyperglycemic patients had no prior history of diabetes. The mortality rate for hypoglycemic patients was 22.2%; for hyperglycemic patients it was 11.1%. For all other hospitalized patients it was 2.3% (p < 0.0001). Mortality rates for the black and Hispanic patients who were hypoglycemic (30% and 46%) were significantly higher than for white patients (6%, p < 0.01). CONCLUSIONS: Hypoglycemia and severe hyperglycemia are not uncommon in hospitalized patients and serve as metabolic markers for patients at increased risk for inhospital mortality. Early identification of at-risk patients and the impact of aggressive treatment of their underlying disease processes should be evaluated in future studies.