Assessment of Correlation Between Glycaemic Variability Indices and Measures of Hypoglycaemia in Patients with Type 2 Diabetes Mellitus

Introduction: Diabetes mellitus is a global health burden, and India is regarded as the diabetes capital of the world. Glycaemic variability (GV) is an established risk factor for hypoglycaemia (plasma glucose concentration <70 mg/dL) and a notorious risk factor for diabetes complications. The primary aim of the study was to assess the correlation between the GV indices, HbA1c levels, and measures of hypoglycaemia in patients with type 2 DM (T2DM).

Methods: In this cross-sectional study, continuous glucose monitoring (CGM) was done for a period of 14 days in T2DM patients (n = 50). The GV indices were determined from the readings obtained from the CGM monitor. Spearman's rank correlation coefficient was used for correlation analyses. The area under the receiver operating characteristics (ROC) curve was used to assess the effectiveness of the various GV indices in predicting hypoglycaemia.

Results: A total of 50 T2DM patients had a mean (SD) age of 61.84 ± 11.88 years. Among the GV indices, high blood glucose index (HBGI), average daily risk range (ADRR), and continuous overall net glycaemic action (CONGA) had a significantly positive correlation with HbA1c levels. Average episodes of nocturnal hypoglycaemia in 8 hours of night-time had a statistically significant negative correlation with the HbA1c levels (correlation coefficient: -0.301, P = 0.034). In addition, low blood glucose index (LBGI) was found to be the best predictor for the risk of hypoglycaemia in 24 hours and nocturnal hypoglycaemia.

Conclusion: Various GV indices are associated with HbA1c levels and are better predictors of hypoglycaemia.