Background: Glycemic variability (GV) considers intraday glycemic excursions as well as glucose fluctuations that occur at the same time on different days.
Aim: To evaluate several GV indices in patients with type 1 diabetes mellitus (T1D) and the association among GV indices and microvascular complications and lipid abnormalities.
Methods: patients from a diabetes clinic in a tertiary care center were divided into 2 groups: HbA1c <7% (10) and between 7–8% (10). A continuous glucose monitoring device (iPro2) was placed for 4 days.
Results: 20 patients were included, 12 (60%) women, median age and diagnosis were 34 (22-46 years) and 16 years, respectively. The median of GV indices were: standard deviation (SD) of 55 mg/dL (40-66 mg/dL), coefficient of variation (CV) of 38%, time in range (TIR) of 50% (40-63%) and time below range was 8%. Patients with HbA1c <7% had a lower average glucose (129 mg/dL vs.146 mg/dL, p=0.04), longer TIR (61% vs. 42%, p=0.006). A HbA1c >7% was significantly associated with higher average glucose and SD, shorter TIR before (p=0.016) and after lunch (p=0.005). Patients with CV >36% had less TIR (42% vs. 58%, p=0.030), longer time below range (18% vs. 3%, p=0.001) and more low excursions.
Conclusions: CV >36% is associated with a shorter time in range, longer hypoglycemia time and more glycemic excursions. HbA1c is related to the average of glucose and TIR but it is not an accurate predictor of hypoglycemia. GV parameters should be measured to assess the possibility of hypoglycemia and inter-day variation.