Real-time continuous glucose monitoring system for treatment of diabetes: a systematic review

This study reviews the effect of real-time continuous glucose monitoring systems in diabetes management.

A systematic search was performed in PubMed/MEDLINE and EMBASE for randomized controlled trials comparing real-time continuous glucose monitoring systems with self-monitoring blood glucose or non-real-time continuous glucose monitoring systems.

Nine randomized controlled trials were identified. Two studies used a device which is not on the market any more. In this review we focus on the other seven studies. Performing a meta-analysis was not possible because of extensive clinical heterogeneity. Six of seven studies showed some positive effect of real-time continuous glucose monitoring systems on HbA(1c) (HbA(1c) decrease 0.3-0.7% or 3-8 mmol/mol). In some studies, this effect only was shown in subgroups (compliant adult patients). However, the size of effect may be underestimated by better-than-average results in the control group, as self-monitoring blood glucose measurements are carried out more frequently than in usual clinical practice. Despite the goal of lowering HbA(1c) , no more severe hypoglycaemic episodes were seen, except in one study. In contrast, no positive effect was shown with the real-time continuous glucose monitoring system on hypoglycaemia, but randomized controlled trials were not designed or powered to investigate this issue. Time in different glucose strata was assessed only in some trials: two of them showed a significant but small increase in time in euglycaemia.

Current evidence shows that the real-time continuous glucose monitoring system has a beneficial effect on glycaemic control in adult diabetes patients, without an increase in the incidence of hypoglycaemia. Studies in well-selected patient groups (pregnancy, history of severe hypoglycaemias, Type 2 diabetes) are lacking.