Results of a Randomised Controlled Cross-Over Trial on the Effect of Continuous Subcutaneous Glucose Monitoring (CGMS) on Glycaemic Control in Children and Adolescents with Type 1 Diabetes

Abstract

To study the feasibility and the influence on glycaemic control of continuous glucose monitoring (CGMS) in young patients with type 1 diabetes. A double-blinded, cross-over study was performed in 30 children (median age 11.1 years [range: 2.3 - 16.3], diabetes duration 2.1 years [0.2 - 7.1]). Patients were randomised into an open (A) or blind study arm (B). Both groups performed standardised self-monitoring blood glucose (SMBG) and received CGMS at the beginning of the study, at 3 and 6 months, each. In the blinded arm, patients and investigator were concealed from CGMS data. After 3 months, open and blinded study arms crossed over. Average glucose values and area under the glucose curve (AUC) per 24 h, above 180 and below 60 mg/dl were calculated from CGMS. Haemoglobin A1c (HbA1c) was measured at each study point. Despite comparable clinical characteristics between the 15 patients of each arm, mean HbA1c was slightly lower in arm A than in B at baseline (7.8 +/- 1.2 % vs. 8.4 +/- 1.1 %, p = 0.148), at 3 months (7.8 +/- 1.1 % vs. 8.3 +/- 1.1 %, p = 0.233), and significantly lower at 6 months (7.6 +/- 1.1 % vs. 8.5 +/- 0.9 %, p = 0.026). However, no significant change of HbA1c occurred within each arm (A, p = 0.183 and B, p = 0.823), irrespectively whether CGMS data were blinded or not. Likewise, mean glucose and hyper- or hypoglycaemia values did not change significantly. In this setting, CGMS did not decisively influence glycaemic control of a total study cohort. More frequent use of CGMS at shorter intervals in single patients with hyper- or hypoglycaemic problems may be of greater value than SMBG.