Hypoglycemia as a predictor of mortality in hospitalized elderly patients

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 I 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, sulfonyurea 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 ere 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, while hypoglyemia 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.