Hypoglycemia as a Predictor of Mortality in Hospitalized Elderly Patients

Abstract

Background: Hypoglycemia during hospitalization occurs in patients with and without diabetes. The aims of this study were to determine the incidence, associated risk factors, and short- and long-term outcome of hypoglycemia among hospitalized elderly patients. Methods: This is a case-control study conducted at geriatric and medicine departments. All patients 70 years or older with documented hypoglycemia hospitalized within 1 year (n = 281) were compared with a nonhypoglycemic group of 281 elderly, randomly selected patients from the same hospitalized population. Results: Among 5404 patients 70 years or older, 281 (5.2%) had documented hypoglycemia. Compared with the nonhypoglycemic group, we found the following characteristics to be true in the hypoglycemic group: there were more women than men (58% vs 44%; p = .001); sepsis was 10 times more common (p < .001); malignancy was 2.8 times more common (p = .04); the mean serum albumin level was lower (2.8 g/dL vs 3.4 g/dL, p < .001); and the mean serum creatinine and alkaline phosphatase levels were higher (p < .001 for both). Diabetes was known in 42% of the hypoglycemic group and in 31% of the nonhypoglycemic group (p = .03); 70 patients in the hypoglycemic group were taking sulfonylureas or insulin. Multivariate logistic analysis showed that sepsis, albumin level, malignancy, sulfonylurea and insulin treatment, alkaline phosphatase level, female sex, and creatinine level were all independent predictors of developing hypoglycemia. In-hospital mortality and 3-month mortality were about twice as high in the hypoglycemic group (p < .001). Multivariate analysis of mortality found that sepsis, low albumin level, and malignancy were independent predictors, whereas hypoglycemia was not. Conclusions: Hypoglycemia was common in elderly hospitalized patients and predicted increased in-hospital 3- and 6-month cumulative mortality. However, in a multivariate analysis, hypoglycemia was not an independent predictor for mortality, implying that it is only a marker.