The contribution of glucose variability to asymptomatic hypoglycemia in persons with type 2 diabetes

Background: The present study was designed to define the relative contributions of glucose variability and ambient glycemia to the incidence of asymptomatic hypoglycemia in type 2 diabetes. Methods: Two hundred twenty-two persons with type 2 diabetes were divided into three groups: Group I (n = 53) on insulin sensitizers alone, Group II (n = 87) on oral hypoglycemic agents (OHAs) to include at least one insulin secretagogue, and Group III (n = 82) on insulin alone or in combination with OHAs. Ambient mean glucose concentration (MG) values (in mmol/L) and glycemic variability (SD around the mean glucose value) (in mmol/L) or mean amplitude of glycemic excursions (in mmol/L) were assessed by a continuous glucose monitoring system. Asymptomatic hypoglycemia was recorded over a 48-h period. Poisson regression analysis was used for assessing the potential predictors of hypoglycaemia. Results: The best model fit was obtained with the two following explanatory variables: MG and SD. Hypoglycemia frequency was negatively associated with MG and positively with SD: Log (number of hypoglycemia episodes) = 1.37 − (0.72 × MG) + (1.33 × SD). Odds ratios (95% confidence interval) for hypoglycemic risk were significantly different from 1 for MG at 0.96 (0.95–0.97) (P < 0.0001) and for SD at 1.08 (1.06–1.10) (P < 0.0001). In addition, the risk for hypoglycemia was completely or virtually eliminated when the SD was