Impact of glycemic variability and hypoglycemia on adverse hospital outcomes in non-critically ill patients

Aims: To determine if glycemic variability is associated with hospitalization outcomes in non-critically ill patients, and if this association remains after controlling for hypoglycemia. Methods: A retrospective review was performed on 1276 medical admissions (801 patients) in which insulin was given, >= 6 point of care glucose (POCG) measurements and length of stay (LOS) 2-30 days. Coefficient of variation (%CV) was used to measure glycemic variability. Outcomes included LOS and a composite outcome based on ICU transfer, hospital acquired infections, and acute renal failure (ARF). Results: There were a median of 18.5 POCG measurements per admission with a mean %CV 34.2 +/- 11.1. Hypoglycemia (POCG <= 70 mg/dl [3.9 mmol/l]) occurred in 35.0% of admissions. ICU transfer occurred in 3.3%, hospital acquired infections 4.8%, ARF 8.3%, and composite outcome 13.5%. Adjusting for age, sex, race and Charlson score, every 10 unit increase in %CV was associated with an increase in LOS of 0.27 days (p = 0.004), while there was no association between %CV and the composite outcome. For LOS, there was a significant interaction between %CV and hypoglycemia (p = 0.07). While there was a non-significant correlation in patients without hypoglycemia, LOS correlated negatively with %CV in patients with hypoglycemia. When considered simultaneously with %CV, hypoglycemia was associated with increased odds of the composite outcome [OR 2.03 (95% CI 1.36-3.01), p = <0.001] and an increase of 2 days in LOS for those with average %CV. Conclusions: Hypoglycemia, compared to glycemic variability, is more strongly associated with adverse outcomes in hospitalized, non-critically ill patients. (C) 2014 Elsevier Ireland Ltd. All rights reserved.