Real-time continuous glucose monitoring improves glycemic control compared to intermittently scanned monitoring for patients with type 1 diabetes

1. Time in range after 6 months was higher with rtCGM than with isCGM.

2. Participants on rtCGM scored better on the satisfaction subscale of the Diabetes Treatment Satisfaction Questionnaire status (mean difference of 2.34 points).

Evidence Rating Level: 1 (Excellent)

Study Rundown: Progress in the field of home glucose monitoring systems has allowed for the ability to measure glycemic levels on demand (intermittently scanned continuous glucose monitoring [isCGM]), or in real time (real-time continuous glucose monitoring [rtCGM]). However, it remains unclear as to whether switching from isCGM to rtCGM with alert functionality offers additional benefits. This randomized controlled trial aimed to assess whether switching from isCGM to rtCGM offers additional benefits by comparing 6-month rtCGM use with 6-month isCGM use in adults with type 1 diabetes who were previously using isCGM. The primary outcome was time in range (sensor-glucose of 3.9-10.0 mmol/L) at 6 months, while key secondary outcomes included HbA_1c, time in significant hypoglycemia (sensor-glucose less than 3.0 mmol/L), and hypoglycemia fear – all evaluated at 6 months. According to study results, switching from isCGM to rtCGM significantly improved time in range after 6 months of treatment, implying that clinicians should consider rtCGM instead of isCGM to improve health and quality of life of patients with type 1 diabetes. However, a limitation of this study is the lack of clinical markers assessed, including time to micro and macrovascular complications as well as incidence of hospital admission. Nevertheless, it provided valuable insight into the effectiveness of rtCGM for glycemic control in patients with type 1 diabetes.

Click to read the study in The Lancet

Relevant Reading: A Randomized Trial of Closed-Loop Control in Children with Type 1 Diabetes

In-depth [randomized controlled trial]: Between Jan 29 and July 30, 2019, 269 patients were assessed for eligibility at six hospitals in Belgium. Included patients were ≥ 18 years of age with a diagnosis of type 1 diabetes, treated with multiple daily injections or insulin pump, HbA_1c ≤10%, and exclusive isCGM use ≥ 6 months. Those with severe cognitive impairment limiting CGM use, use of systemic corticosteroids, or planned pregnancy were excluded. Altogether, 246 patients (124 in rtCGM group and 122 in isCGM group) completed the study at 6 months. The mean patient age was 42.9 years (standard deviation [SD] 14.1, range 18-76 years) and majority (94%) were White. Both groups had similar baseline characteristics.

The primary outcome of time in range after 6 months was higher with rtCGM than with isCGM (59.6% vs. 51.9%, 95% confidence interval [CI] 4.36-9.34, p<0.0001). Additionally, the secondary outcome of HbA_1c was lower (7.1% rtCGM vs. 7.4% isCGM, p<0.0001), as was time in significant hypoglycemia (0.47% vs. 0.84%, p=0.007), and hypoglycemia fear (evaluated using the Hypoglycemia Fear Survey version II worry subscale score 15.4 vs. 18.0, p=0.0071). At 6 months, the rtCGM group scored better on the satisfaction subscale than the isCGM group (mean difference of 2.34 points, 95% confidence interval [CI] 1.15-2.54, p=0.0001). Moreover, fewer rtCGM users experienced severe hypoglycemia (2% vs. 11%, 95% CI -14.3 to -2.1, p=0.0082); although, bleeding after sensory insertion was reported by only rtCGM users (n=12). Overall, rtCGM showed significant benefits for glycemic control and patient-reported satisfaction compared to isCGM for patients with type 1 diabetes. 

Image: PD

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