Documented hypoglycemia is associated with poor short and long term prognosis among patients admitted to general internal medicine departments

Aim: To study the association of documented hypoglycemia with length of stay, 30-day mortality, and 1-year mortality, among patients with and without diabetes admitted to internal medicine units.

Methods: The electronic medical records of all patients hospitalized in internal medicine departments at E. Wolfson Medical Center, Holon, Israel, between 1/1/2010 and 31/12/2013, were reviewed. Data extracted included all glucose measurements (performed using an institutional blood glucose monitoring system). Patients were considered hypoglycemic if at least one hypoglycemic event was recorded. Regression analysis was used to assess the association between documented hypoglycemia and length of stay, 30-day and one-year mortality. Age, sex, reason for admission, and the Charlson comorbidity index were entered as covariates, and the most conservative model was developed.

Results: The study population included 45,272 patients (mean age 68.9 ± 17.8 years, 49.4% males, 21.0% had diabetes mellitus). The rate of hypoglycemia in the total study population was 7.5% (16.8% among DM patients, 6.0% among patients without diabetes, p < 0.001). Patients with documented hypoglycemia had a longer length of hospital stay (9.3 ± 18.7 vs. 3.1 ± 6.4 days, p < 0.001), as well as higher risk for both 30-day (23.7% vs. 7.0%, p < 0.001) and 1-year mortality (41.6% vs. 15.3%, p < 0.001). Cox regression analysis showed that hypoglycemia significantly increased risk death at one year (HR 2.436, 95% CI 2.298-2.582, p < 0.001) independent of age, sex, the Charlson comorbidity index, DM status and reason for admission.

Conclusion: Documented hypoglycemia is associated with prolonged length of hospital stay and increased risk for both 30-day and 1-year mortality, regardless of diabetes mellitus status.