Comparing the glycaemic outcomes between real-time continuous glucose monitoring (rt-CGM) and intermittently scanned continuous glucose monitoring (isCGM) among adults and children with type 1 diabetes: A systematic review and meta-analysis of randomized controlled trials.

Aim: To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the effectiveness of real-time continuous glucose monitoring (rtCGM) versus intermittently scanned continuous glucose monitoring (isCGM) on key glycaemic metrics (co-primary outcomes HbA1c and time-in-range [TIR] 70-180 mg/dL, 3.9-10.0 mmol/L) among people with type 1 diabetes (T1D).

Methods: Medline, PubMed, Scopus, Web of Science and Cochrane Central Register of clinical trials were searched. Inclusion criteria were RCTs; T1D populations of any age and insulin regimen; comparing any type of rtCGM with isCGM (only the first generation had been compared to date); and reporting the glycaemic outcomes. Glycaemic outcomes were extracted post-intervention and expressed as mean differences and 95% CIs between the two comparators. Results were pooled using a random-effect meta-analysis. The risk of bias was assessed using the Cochrane RoB2 tool. The quality of evidence was assessed by the GRADE approach.

Results: Five RCTs met the inclusion criteria (4 parallel and 1 crossover design; 4 with CGM use <8 weeks), involving 446 participants (354 adults; 92 children and adolescents). Overall, meta-analysis showed rtCGM compared to isCGM improved absolute TIR by +7.0% (95% CI: 5.8%-8.3%, I  = 0%, p < 0.01) accompanied by a favorable effect on time-below-range <70 mg/dL (3.9 mmol/L) - 1.7% (95%CI: -3.0% to -0.4%; p = 0.03). No differences were seen regarding HbA1c.

Conclusions: This meta-analysis highlights that for people with T1D, rtCGM confers benefits over isCGM primarily related to increased TIR, with improvements in hypo- and hyperglycaemia.