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Intermittently scanned continuous glucose monitoring in adults with type 1 diabetes: A subgroup analysis from the FLASH-UK study.

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Leelarathna, Lalantha 
Sutton, Christopher J 
Evans, Mark L 
Neupane, Sankalpa 
Rayman, Gerry 


BACKGROUND: The FLASH-UK trial showed lower HbA1c with intermittently-scanned continuous glucose monitoring (isCGM), as compared with self-monitoring of blood glucose (SMBG), in adults with type 1 diabetes and HbA1c ≥58 mmol/mol. (≥ 7.5%). Here we present results from the pre-specified subgroup analysis for the 24-week HbA1c (primary outcome) and selected sensor-based secondary outcomes. METHODS: This was a multicentre, parallel-design, randomised controlled trial. The difference in treatment effect between subgroups (baseline HbA1c (≤75 vs >75 mmol/mol (≤9.0 vs > 9.0%), treatment modality (pump vs injections), prior participation in structured education, age, educational level, impaired awareness of hypoglycaemia, deprivation index quintile sex, ethnic group, and Patient Health Questionnaire-9 (PHQ-9) detected depression category) were evaluated. RESULTS: One hundred fifty-six participants [females 44%, mean (SD) baseline HbA1c 71 (9) mmol/mol 8.6(0.8%), age 44 (15)] were randomly assigned, in a 1:1 ratio to isCGM (n=78) or SMBG (n=78). The mean (SD) baseline HbA1c (%) was 8.7 (0.9) in the isCGM group and 8.5 (0.8) in the SMBG group, lowering to 7.9 (0.8) vs 8.3 (0.9) respectively at 24 weeks (adjusted mean difference -0.5, 95% confidence interval[CI] -0.7 to -0.3; p<0.001]. For HbA1c, there was no impact of treatment modality, prior participation in structured education, deprivation index quintile, sex or baseline depression category. The between-group difference in HbA1c was larger for younger people [a reduction of 2.7 (95%CI 0.3 to 5.0; p=0.028) mmol/mol for every additional 15 years of age]. Those with HbA1c 76-97 mmol/mol (>9.0-11.0%) had a marginally non-significant higher reduction in HbA1c of 8.4 mmol/mol (3.3 to 13.5) compared to 3.1 (0.3 to 6.0) in those with HbA1c 58-75mmol/mol (p=0.08). For "Time in range" (% 3.9 to 10 mmol/l), the difference was larger for those with at least a bachelor's degree. For "Time below range" (% <3.9 mmol/l), the difference was larger for those using injections, older people, and those with less than bachelor's degree. CONCLUSIONS: Intermittently-scanned continuous glucose monitoring is generally effective across a range of baseline characteristics.



FLASH-UK Trial Study Group

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Diabet Med

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This work was supported by Diabetes UK grant number 18/0005836. The device manufacturer played no part in design, conduct or any other aspects of the study. The study devices were funded by the National Health Service (NHS) UK. Work was supported by the NIHR Cambridge Biomedical Research Centre. The University of Cambridge has received salary support for MLE from the National Health Service in the East of England through the Clinical Academic Reserve.