Relationship between daily and visit-to-visit glycemic variability in patients with type 2 diabetes

The aim of the study was to explore the relationship between daily glycemic variability (GV) and visit-to-visit glycemic variability (VVV) in patients with type 2 diabetes (T2DM). A total of 156 outpatients with T2DM who had undergone continuous glucose monitoring (CGM) for 5 days were included in this study. Indices of GV, i.e., standard deviation and coefficient of variation (CV) of glucose, mean amplitude of glycemic excursion (MAGE) and mean of the daily differences (MODD) were calculated from the CGM data. VVV was calculated as CV of HbA1c or glycated albumin (GA) from HbA1c or GA measured for 3 years. Relationships among clinical parameters, GV and VVV were evaluated. Age was positively, and BMI and C-peptide index were inversely correlated with GV such as CV glucose and MAGE, while BMI was positively correlated with VVV. Mean glucose rather than GV was correlated with VVV. In contrast, time in range (TIR, 70-180 mg/dL) was correlated with both mean HbA1c or GA and VVV. In conclusion, GV and VVV were differently correlated with clinical parameters and were hardly correlated with each other. TIR was correlated with both mean HbA1c and VVV, suggesting that efforts to achieve optimal TIR are practical strategies to reduce VVV in patients with T2DM.