Assessment of glycemic lability and severity of hypoglycemia in Korean patients with type 1 diabetes

Few studies have focused on the quantification of glycemic lability and hypoglycemic events in Asian patients with type 1 diabetes; therefore, we conducted a study to assess glycemic lability and the severity of hypoglycemia in type 1 diabetic patients in Korea. A total of 124 type 1 diabetic patients were enrolled. Several glycemic lability indexes and hypoglycemic indexes were calculated using four-week self-monitoring of blood glucose (SMBG) data. Due to the dependence of the lability index (LI) on the frequency of glucose measurements, we generated a modified LI by dividing by the number of SMBG measurements per day for a given patient. The numbers of patients in our study with a composite hypoglycemic score ≥ 1,047 or LI ≥ 433 mmol/L2/h•week-1, which was found in a previous study to indicate high risk of severe hypoglycemia or lability, were 0 (0%) and 44 (35%), respectively. Compared to previously reported hypoglycemia indexes, the low blood glucose index was lower in our study. However, the glycemic lability indexes were similar to those in previous studies, with the exception of the LI. The modified LI and the average daily risk range (ADRR) showed higher concordance with other glycemic lability indexes than did the LI or mean amplitude of glycemic excursions (MAGE). The results showed that the hypoglycemic indexes in this study population were lower than the results from Ryan et al. Furthermore, the ADRR or modified LI were better measures for high risk of severe lability than were the LI and MAGE.