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Randomized Controlled Trial
. 2021 Jun 12;397(10291):2275-2283.
doi: 10.1016/S0140-6736(21)00789-3. Epub 2021 Jun 2.

Comparing real-time and intermittently scanned continuous glucose monitoring in adults with type 1 diabetes (ALERTT1): a 6-month, prospective, multicentre, randomised controlled trial

Margaretha M Visser  1 , Sara Charleer  1 , Steffen Fieuws  2 , Christophe De Block  3 , Robert Hilbrands  4 , Liesbeth Van Huffel  5 , Toon Maes  6 , Gerd Vanhaverbeke  7 , Eveline Dirinck  3 , Nele Myngheer  7 , Chris Vercammen  6 , Frank Nobels  5 , Bart Keymeulen  4 , Chantal Mathieu  1 , Pieter Gillard  8
Affiliations
Randomized Controlled Trial

Comparing real-time and intermittently scanned continuous glucose monitoring in adults with type 1 diabetes (ALERTT1): a 6-month, prospective, multicentre, randomised controlled trial

Margaretha M Visser et al. Lancet. .

Abstract

Background: People with type 1 diabetes can continuously monitor their glucose levels on demand (intermittently scanned continuous glucose monitoring [isCGM]), or in real time (real-time continuous glucose monitoring [rtCGM]). However, it is unclear whether switching from isCGM to rtCGM with alert functionality offers additional benefits. Therefore, we did a trial comparing rtCGM and isCGM in adults with type 1 diabetes (ALERTT1).

Methods: We did a prospective, double-arm, parallel-group, multicentre, randomised controlled trial in six hospitals in Belgium. Adults with type 1 diabetes who previously used isCGM were randomly assigned (1:1) to rtCGM (intervention) or isCGM (control). Randomisation was done centrally using minimisation dependent on study centre, age, gender, glycated haemoglobin (HbA1c), time in range (sensor glucose 3·9-10·0 mmol/L), insulin administration method, and hypoglycaemia awareness. Participants, investigators, and study teams were not masked to group allocation. Primary endpoint was mean between-group difference in time in range after 6 months assessed in the intention-to-treat sample. This trial is registered with ClinicalTrials.gov, NCT03772600.

Findings: Between Jan 29 and Jul 30, 2019, 269 participants were recruited, of whom 254 were randomly assigned to rtCGM (n=127) or isCGM (n=127); 124 and 122 participants completed the study, respectively. After 6 months, time in range was higher with rtCGM than with isCGM (59·6% vs 51·9%; mean difference 6·85 percentage points [95% CI 4·36-9·34]; p<0·0001). After 6 months HbA1c was lower (7·1% vs 7·4%; p<0·0001), as was time <3·0 mmol/L (0·47% vs 0·84%; p=0·0070), and Hypoglycaemia Fear Survey version II worry subscale score (15·4 vs 18·0; p=0·0071). Fewer participants on rtCGM experienced severe hypoglycaemia (n=3 vs n=13; p=0·0082). Skin reaction was more frequently observed with isCGM and bleeding after sensor insertion was more frequently reported by rtCGM users.

Interpretation: In an unselected adult type 1 diabetes population, 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 the health and quality of life of people with type 1 diabetes.

Funding: Dexcom.

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Conflict of interest statement

Declaration of interests UZ Leuven received non-financial support for travel from Novo Nordisk for MMV. KU Leuven received non-financial support for travel from Medtronic, and financial support for travel from Roche for SC. CDB reports consulting fees and honoraria for speaking for Abbott, AstraZeneca, Boehringer Ingelheim, A Menarini Diagnostics, Eli Lilly, Medtronic, Novo Nordisk, and Roche. RH serves or has served on the advisory panel for Merck Sharp and Dohme, Boehringer Ingelheim, and Eli Lilly. LVH reports consulting fees and honoraria for speaking for Abbott, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Medtronic, Merck Sharp and Dohme, Novo Nordisk, and Sanofi-Aventis. GV serves or has served on the advisory panel for Merck Sharp and Dohme, Boehringer-Ingelheim, and Eli Lilly; reports consulting fees and honoraria for speaking from Merck Sharp and Dohme, Boehringer Ingelheim, AstraZenica, Sanofi-Aventis, Novo Nordisk, and Eli Lilly. ED has served on the advisory panel for Novo Nordisk; ED reports speaking fees from Novo Nordisk, Boehringer-Ingelheim, Eli Lilly, and AstraZenica. NM serves or has served on the advisory panel for Boehringer-Ingelheim; and reports speaking fees from Merck Sharp and Dohme, Boehringer-Ingelheim, AstraZenica, Sanofi-Aventis, Novo Nordisk, and Eli Lilly. CV reports consulting and speaking fees from Medtronic, Boehringer Ingelheim, Astra Zeneca, and Sanofi Aventis. FN reports consulting fees and honoraria for speaking from Abbott, AstraZeneca, Boehringer-Ingelheim, Eli Lilly, Johnson and Johnson, Medtronic, Merck Sharp and Dohme, Novo Nordisk, Roche, and Sanofi-Aventis. CM serves or has served on the advisory panel for Novo Nordisk, Sanofi-Aventis, Merck Sharp and Dohme, Eli Lilly, Novartis, AstraZeneca, Boehringer-Ingelheim, Roche, Medtronic, ActoBio Therapeutics, Pfizer, and Zealand Pharma (financial compensation for these activities has been received by KU Leuven; KU Leuven has received research support for CM from Medtronic, Novo Nordisk, Sanofi-Aventis, Merck Sharp and Dohme, Eli Lilly, Roche, Abbott, ActoBio Therapeutics, and Novartis); serves or has served on the speakers' bureau for Novo Nordisk, Sanofi-Aventis, Merck Sharp and Dohme, Eli Lilly, Boehringer Ingelheim, AstraZeneca, and Novartis (financial compensation for these activities has been received by KU Leuven). PG serves or has served on the advisory panel for Novo Nordisk, Sanofi-Aventis, Boehringer-Ingelheim, Janssen Pharmaceuticals, Roche, Medtronic, and Bayer (financial compensation for these activities has been received by KU Leuven). PG serves or has served on the speakers bureau for Merck Sharp and Dohme, Boehringer-Ingelheim, Bayer, Medtronic, Insulet, Novo Nordisk, Abbott, and Roche (financial compensation for these activities has been received by KU Leuven and KU Leuven received for PG non-financial support for travel from Sanofi-Aventis, A Menarini Diagnostics, Medtronic, and Roche); and received a grant for a senior clinical research fellowship from Fonds Wetenschappelijk Onderzoek Flanders. SC received a doctoral grant for strategic basic research from Fonds Wetenschappelijk Onderzoek Flanders. All disclosures are unrelated to the present work. All other authors declare no competing interests.

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