Continuous and flash glucose monitoring (CGM/FGM) improve outcomes in type 1 diabetes (T1D). No data comparing CGM and FGM in patients treated with MDI (multiple daily injection) during sustained physical activity are available. The study aim was to compare efficacy and accuracy of using CGM and FGM in T1D children on MDI during sustained physical activity at sport camp.
Twenty-two children with T1D (8 boys, aged 8-14 years, mean HbA1c 51±1.4 mmol/mol) were prospectively followed up over 6 days and nights at sport camp. Participants were divided into two groups; CGM (DexcomG5®/DexcomG4®, n=12) and FGM (Abbott Free Style Libre®, n=13). Physical exertion was represented by various aerobic and anaerobic activities. Glucose control was evaluated by mean glycemia, time in range (3.9-10 mmol/l), hypoglycemia (<3.9 mmol/l) and hyperglycemia (>10 mmol/l), and by glycemic variability (standard deviation of glycaemia). The CGM/FGM accuracy was evaluated using MARD calculated from finger prick blood glucose measuring performed at least 5 times a day. ANOVA Kruskal-Wallis test was used for statistic evaluation.
The groups did not differ significantly in time in range (67% vs 61% for GCM vs FGM, respectively; p=0.20) or time in hypoglycemia (11.5% vs 15.5%, p=0.37). However, the CGM group had significantly lower mean glycemia (7.1 vs. 8.5 mmol/l, p=0.015), shorter time in hyperglycemia (17.0% vs. 30.5%, p=0.028) and lower glycemic variability (SD 3.3 vs. 4.2 mmol/l, p=0.016). CGM had greater accuracy compared to FGM (MARD 17.6% vs. 19.9%, p=0.022).
Longer time in hyperglycemia in FGM group might be explained by intermittent scanning only.