Three-day continuous glucose monitoring for rapid assessment of hypoglycemic events and glycemic variability in type 1 diabetic patients

This study was to determine whether glycemic variability is related to hypoglycemic events in type 1 diabetic patients, and whether the hypoglycemic events during a short-term continuous glucose monitoring system (CGMS) period parallel those measured during a 4-week self-monitoring of blood glucose (SMBG) period. We also evaluated whether glycemic variability indexes from a short term CGMS correlate with those from a 4-week SMBG. A total of 49 type I diabetic patients wore CGMS devices for 3 days. These patients also performed SMBG for 4 weeks. Several indexes from the CGMS data were compared with indexes from the SMBG data. Hypoglycemic events (glucose levels <70 mg/dL) that occurred during the 3-day CGMS and 4-week SMBG periods were evaluated and compared. Hypoglycemic events were detected in 33 patients (67%) during the 3-day CGMS period. The patients with hypoglycemic events had a significantly higher glycemic variability index divided by mean glucose of CGMS, and a higher number of hypoglycemic events during the 4-week SMBG, compared to those with non-hypoglycemic events during the 3-day CGMS period. The percentage of hypoglycemic events using the 3-day CGMS was correlated with that from the 4-week SMBG (r = 0.49, P < 0.05) and low blood glucose index (r = 0.51, P < 0.05). The glycemic variability indexes from the 4-week SMBG correlated with the glycemic variability indexes from the 3-day CGMS. The short-term CGMS appears to be clinically useful for rapidly assessing the risk of hypoglycemic events and glycemic variability.