Continuous glucose monitoring and the reality of metabolic control in preschool children with type 1 diabetes.

OBJECTIVE To determine using the MiniMed continuous glucose monitoring system (CGMS) 1) whether twice-daily insulin injection therapy achieves adequate control in preschool children with type 1 diabetes and 2) whether the CGMS is more informative than self-monitoring of blood glucose (SMBG) regarding glucose control and well tolerated by preschool children and their families. RESEARCH DESIGN AND METHODS Ten children <6 years of age with type 1 diabetes were monitored twice using the CGMS. The distribution of glucose values was analyzed, particularly the frequency, duration, and distribution of hypoglycemia. We analyzed the accuracy of the CGMS in detecting hypoglycemia as well as the clinical relevance of the difference between CGMS and SMBG values. RESULTS Although hypoglycemia was more frequent during the night (0.8 nighttime episodes . subject(-1) . 24 h(-1) vs. 0.3 daytime episodes . subject(-1) . 24 h(-1)), the difference did not reach statistical significance (P=0.07). However, nighttime episodes lasted longer than daytime episodes (1.2 vs. 0.2 h . subject(-1) . 24 h(-1), P=0.006). Hypoglycemia accounted for 7% and normoglycemia for 24%, while hyperglycemia occurred 64% of the time, with postprandial hyperglycemia being an almost universal feature (94 +/- 7% of all postmeal values). The CGMS correlated well with SMBG without significant clinical discrepancy. The CGMS sensitivity to detect hypoglycemia was 70% with a specificity of 99%; however, the CGMS detected twice as many total episodes as SMBG (82 vs. 40). CONCLUSIONS Twice-daily insulin injection rarely achieves control in preschool children with type 1 diabetes. The CGMS is well tolerated by patients and has the advantage of revealing daily glucose trends missed by SMBG.