Marked improvement in HbA(1c) following commencement of flash glucose monitoring in people with type 1 diabetes

AIMS/HYPOTHESIS: Minimal evidence supports the efficacy of flash monitoring in lowering HbA(1c). We sought to assess the impact of introducing flash monitoring in our centre. METHODS: We undertook a prospective observational study to assess change in HbA(1c) in 900 individuals with type 1 diabetes following flash monitoring (comparator group of 518 with no flash monitoring). Secondary outcomes included changes in hypoglycaemia, quality of life, flash monitoring data and hospital admissions. RESULTS: Those with baseline HbA(1c) ≥58 mmol/mol (7.5%) achieved a median −7 mmol/mol (interquartile range [IQR] −13 to −1) (0.6% [−1.2 to −0.1]%) change in HbA(1c) (p < 0.001). The percentage achieving HbA(1c) <58 mmol/mol rose from 34.2% to 50.9% (p < 0.001). Median follow-up was 245 days (IQR 182 to 330). Individuals not using flash monitoring experienced no change in HbA(1c) across a similar timescale (p = 0.508). Higher HbA(1c) (p < 0.001), younger age at diagnosis (p = 0.003) and lower social deprivation (p = 0.024) were independently associated with an HbA(1c) fall of ≥5 mmol/mol (0.5%). More symptomatic (OR 1.9, p < 0.001) and asymptomatic (OR 1.4, p < 0.001) hypoglycaemia was reported after flash monitoring. Following flash monitoring, regimen-related and emotional components of the diabetes distress scale improved although the proportion with elevated anxiety (OR 1.2, p = 0.028) and depression (OR 2.0, p < 0.001) scores increased. Blood glucose test strip use fell from 3.8 to 0.6 per day (p < 0.001). Diabetic ketoacidosis admissions fell significantly following flash monitoring (p = 0.043). CONCLUSIONS/INTERPRETATION: Flash monitoring is associated with significant improvements in HbA(1c) and fewer diabetic ketoacidosis admissions. Higher rates of hypoglycaemia may relate to greater recognition of hitherto unrecognised events. Impact upon quality of life parameters was mixed but overall treatment satisfaction was overwhelmingly positive. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00125-019-4894-1) contains peer-reviewed but unedited supplementary material, which is available to authorised users.