Impact of flash glucose monitoring versus capillary blood glucose monitoring on glycaemia in Indian youth with type 1 diabetes: a randomised crossover study

Abstract Background Data relating to flash glucose monitoring (FGM) use in low-resource settings are limited. Our study investigated the impact of FGM versus self-monitoring of blood glucose (SMBG) on glycaemia in Ahmedabad, India. Methods A randomised crossover study of FGM versus SMBG was undertaken. Participants aged 10–25 years (type 1 diabetes (T1D)>1 year) were randomised 1:1 to either Freestyle Libre 1 FGM use (intervention) for 6 months, followed by SMBG≥4 times/day (local care standard) for 6 months; or SMBG≥4 times/day, followed by FGM. After 12 months, everyone entered a 6-month observation period using the monitoring method choice. Insulin and dietary adjustments were undertaken as per local care standards. Glycated haemoglobin (HbA1c) was measured at 0, 3 and 6 months (period 1) and 9 and 12 months (period 2). Analyses included use of linear mixed-effects analysis of covariance, a paired Wilcoxon signed-rank test, and cumulative link mixed tests and model. Results Of 106 participants, 91 (86%) completed 12 months follow-up (47.3% female). At baseline, mean±SD age was 17.8±3.8 years, diabetes duration 9.9±5.0 years and HbA1c 8.6±1.9% (70±21 mmol/mol). HbA1c decreased when using FGM versus SMBG (difference −0.44% (4.8 mmol/mol); p=0.006), with greater reduction in those with higher baseline HbA1c (p=0.003). In the FGM→SMBG group, HbA1c initially decreased from 8.6±2.2% (70±24 mmol/mol) to 7.9±1.1% (62±12 mmol/mol) at 3 and 6 months (both p<0.05). After SMBG crossover, HbA1c was unchanged (7.9±1.1% (63±12 mmol/mol) at 9 months and 8.1±1.3% (65±14 mmol/mol) at 12 months). In the SMBG→FGM group, HbA1c was initially stable (8.6±1.4% (70±15 mmol/mol) at baseline; 8.8±1.7% (73±19 mmol/mol) at 6 months), but decreased after crossover to FGM (8.4±1.4% (68±15 mmol/mol) at 9 months; 8.3±0.9% (67±10 mmol/mol) at 12 months; p=0.023). Conclusion This study provides evidence of improvement in glycaemic outcomes while using FGM in youth living with T1D in India. Trial registration number Clinical Trial Registry of India (CTRI/2022/02/020175).