Glycemic Variability and Hospital Outcomes in Diabetic Patients: A Prospective Observational Study

Abstract

Background: Glycemic variability (GV), reflecting the magnitude and frequency of fluctuations in blood glucose levels, has emerged as a clinically significant dimension of glycemic control beyond static measures such as glycated hemoglobin (HbA1c). In hospitalized diabetic patients, dysregulation of glucose homeostasis is associated with heightened oxidative stress, endothelial dysfunction, and impaired immune responses, all of which may adversely influence clinical outcomes.

Aim: This study aimed to evaluate the association between GV and hospital outcomes including length of stay (LOS), intensive care unit (ICU) admission, 30-day readmission rates, and in-hospital mortality among diabetic patients admitted to a tertiary care center.

Methods: A prospective observational cohort study was conducted across three hospital wards over 12 months. A total of 320 diabetic patients were enrolled and stratified into three tertiles based on the coefficient of variation of blood glucose (CV-BG). GV indices including mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), and J-index were computed. Multivariate logistic regression was performed to identify independent predictors of adverse outcomes.

Results: Patients in the highest GV tertile (CV-BG >36%) demonstrated significantly prolonged LOS (9.6 ± 4.9 vs. 4.1 ± 2.3 days; p<0.001), higher ICU admission rates (31.1% vs. 9.3%; p<0.001), greater 30-day readmission (35.8% vs. 12.1%; p<0.001), and elevated in-hospital mortality (11.3% vs. 2.8%; p=0.012) compared to the lowest GV tertile. On multivariate regression, high GV independently predicted prolonged LOS (OR 3.82; 95% CI 2.41–6.04), ICU admission (OR 3.14; 95% CI 1.74–5.66), and inhospital mortality (OR 4.21; 95% CI 1.79–9.87).

Conclusion: Elevated glycemic variability is independently associated with worse hospital outcomes in diabetic patients. Routine assessment and active management of GV during hospitalization should be incorporated into standardized inpatient diabetic care protocols to improve clinical outcomes.