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

Objective: To Study the feasibility and the influence on glycaemic control of continuous glucose monitoring (CGMS) in young patients with type 1 diabetes. Design and Methods: 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. Results: Despite comparable clinical characteristics between the 15 patients of each arm, mean HbA1c was slightly lower in arm A than in Bat 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. Conclusions: 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.