Effect of divergent continuous glucose monitoring technologies on glycaemic control in type 1 diabetes mellitus: A systematic review and meta‐analysis of randomised controlled trials

Abstract

Aims:We aimed to conduct a systematic review and meta-analysis of randomised controlled clinical trials (RCTs) assessing separately and together the effect of the three distinct categories of continuous glucose monitoring (CGM) systems (adjunctive, non-adjunctive and intermittently-scanned CGM [isCGM]), compared with traditional capillary glucose monitoring, on HbA1c and CGM metrics. Methods: PubMed, Web of Science, Scopus and Cochrane Central register of clinical trials were searched. Inclusion criteria were as follows: randomised controlled trials; participants with type 1 diabetes of any age and insulin regimen; investigating CGM and isCGM compared with traditional capillary glucose monitoring; and reporting glycaemic outcomes of HbA1c and/or time-in-range (TIR).Glycaemic outcomes were extracted post-intervention and expressed as mean differences and 95%CIs between treatment and comparator groups. Results were pooled using a random-effects meta-analysis. Risk of bias was assessed using the Cochrane Rob2 tool.Results: This systematic review was conducted between January and April 2021; it included 22 RCTs (15 adjunctive, 5 non-adjunctive, and 2 isCGM)). The overall analysis of the pooled three categories showed a statistically significant absolute improvement in HbA1c percentage points (mean difference (95% CI): −0.22%

Inequity in access to continuous glucose monitoring and health outcomes in paediatric diabetes, a case for national continuous glucose monitoring funding: a cross-sectional population study of children with type 1 diabetes in New Zealand

“…The study has several limitations including an inability to make a causal inference (the cross-sectional nature does not preclude the possibility that participants with lower HbA1c were more likely to adopt CGM), but our findings are consistent with randomised controlled trials showing improved glycaemic control in CGM intervention groups. 1 The study design did not account for participants who recently stopped using CGM (such as an inability to continue funding it, or device intolerance), and binary data on CGM use was collected (‘yes’ or ‘no’) rather than clarifying if participants met recommended CGM data sufficiency criteria. 5 The data is also limited by the accuracy of data collected by DHBs since no secondary data validation was undertaken by the researchers.…”

“…Several randomised controlled trials (RCTs) show continuous glucose monitoring (CGM) systems improving glycaemic outcomes, especially time in range (TIR) and reduced hypoglycaemia, for people with type 1 diabetes (T1D) regardless of age, mode of insulin delivery, glycaemic control, and impaired hypoglycaemic awareness. 1 Real-world data now exists, confirming the positive impact of CGM on glycaemic outcomes 2 , 3 and early adoption is associated with improved long-term outcomes. 4 Accordingly, clinical guidelines for CGM use have been devised internationally, 5 , 6 and diabetes guidelines recommend CGM is offered to all children and adults with T1D.…”

“…Two main types of CGM are currently available; real-time (rtCGM) and intermittently scanned (isCGM). 1 rtCGM automatically transmits continuous glucose data, providing real-time actionable information about current glucose level and trajectory. Comparatively, isCGM relies on manually scanning the sensor to obtain retrospective glucose data.…”

“…rtCGM has been shown to produce higher TIR (3.9–10 mmol/L [70–180 mg/dL]) and less time below range (<3.9 mmol/L [<70 mg/dL]) compared to isCGM in head to head RCTs 9 , 10 , 11 which is also supported in a meta-analysis. 1 Furthermore, rtCGM is an essential component of automated insulin delivery (AID) systems which are superseding sensor augmented pump therapy in the management of T1D. 12…”

Continuous glucose monitoring

“…Systematic review and meta-analysis data show that real-time CGM can improve glycaemic control, and can lead to longer periods in the target glucose range (known as “time in range”), reducing HbA 1c and reducing severe hypoglycaemia 67. Real world evidence suggests reduction in A 1c also occurs with isCGM 8…”