Switching to real-time CGM beneficial for patients with type 1 diabetes: ALERTT1 trial

The study, featured in The Lancet Diabetes and Endocrinology, showed that switching to a real-time continuous glucose monitor from an intermittently scanned CGM (isCGM) significantly improved hypoglycaemia worry and glycemic control in subjects with type 1 diabetes.

ALERTT1 trial investigated if switching from first-generation intermittently scanned CGM without alerts to real-time CGM with alert functionality gives additional benefits to adults with T1D. In the randomised ALERTT1 trial extension, Margaretha M Visser, University Hospitals Leuven – KU Leuven, Leuven, Belgium, and colleagues examined the effect of switching from isCGM to rtCGM for up to 24 months.

The 6-month, parallel-group, double-arm, randomised, non-masked, controlled trial included 254 adults with type 1 diabetes aged 18 years or older previously using isCGM and was conducted across six hospitals in Belgium. They were randomly assigned in a ratio of 1:1 to rtCGM with alerts (intervention) or isCGM without alerts (control), comprising 127 patients in each group.

On completion of the 6-month trial, the intervention group continued rtCGM (rt-rtCGM group), and the control group switched to rtCGM (is-rtCGM group). The extension was centred on within-group changes in time in range (primary outcome; TIR; 3·9–10·0 mmol/L), time in clinically significant hypoglycaemia (<3·0 mmol/L), HbA1c, and HFS-worry score were all prespecified key secondary outcomes. The researchers reported mean within-group change versus the start of rtCGM.

The study led to the following findings:

· 119 participants were assigned to the is-rtCGM group, of whom 94% completed the 24-month trial, and 123 were assigned to the rt-rtCGM group, of whom 95% completed the 24-month trial.

· TIR increased from 51·8% at the start of rtCGM (month 6) to 63·5% in the is-rtCGM group at month 12 and remained stable until month 24.

·TIR increased from 52·5% at the start of rtCGM (month 0) to 63·0% at month 12 in the rt-rtCGM group, remaining stable up to month 24.

· There was a decrease in HbA1c from 7·4% (month 6) to 6·9% (52 mmol/mol) at month 24 in the is-rtCGM group, and in the rt-rtCGM group, it was from 7·4% (month 0) to 7·0% at month 24.

· In the is-rtCGM group, the change in HFS-worry score was –2·67 (month 24 vs month 6) and –5·17 points (month 24 vs month 0) in the rt-rtCGM group.

· In both groups, time in clinically significant hypoglycaemia remained unchanged after month 12.

· After switching to rtCGM, there was a decrease in severe hypoglycaemia from 31·0 to 3·3 per 100 patient years.

"After switching from intermittently scanned CGM without alerts to real-time CGM with alerts, hypoglycaemia worry and glycemic control improved significantly up to 24 months, supporting the rtCGM use in the care of adults with type 1 diabetes," the researchers concluded.

Reference:

Visser MM, Charleer S, Fieuws S, De Block C, Hilbrands R, Van Huffel L, Maes T, Vanhaverbeke G, Dirinck E, Myngheer N, Vercammen C, Nobels F, Keymeulen B, Mathieu C, Gillard P. Effect of switching from intermittently scanned to real-time continuous glucose monitoring in adults with type 1 diabetes: 24-month results from the randomised ALERTT1 trial. Lancet Diabetes Endocrinol. 2023 Feb;11(2):96-108. doi: 10.1016/S2213-8587(22)00352-7. PMID: 36702566.