Background: Rapid improvement in HbA1c has been associated with significant short-term worsening of diabetic retinopathy. Flash monitoring (FM) is associated with significant improvement in HbA1c, particularly in those with high HbA1c at baseline.
Methods: We identified all adults with type 1 diabetes, using NHS reimbursed FM, attending our center. This assessment was limited to those with high microvascular risk defined as duration of diabetes > 3 years and pre-FM HbA1c >9%. From this cohort 40 individuals were selected with the largest post-FM fall in HbA1c (responders) and compared with a further 35 with the smallest change in HbA1c (non-responders). Information on retinopathy status and laser photocoagulation was derived from electronic patient records.
Results: Baseline HbA1c was significantly higher in the responder category (10.5 vs. 9.8%, P = 0.002). Median change in HbA1c, following FM, was -2.5% in responders and +0.2% in non-responders. At baseline, 32% had retinopathy classed as more severe than background (25% had proliferative retinopathy). Median duration from FM commencement to next ophthalmological assessment was 36 weeks (IQR 16 - 50). The percentage with worsening retinopathy did not significantly differ between responders (18%) and non-responders (11%) (P = 0.458). The percentage requiring laser photocoagulation after FM commencement did not differ between responders (17.5%) and non-responders (14.3%) (P = 0.704). Logistic regression analysis identified previous laser (OR 19.9, P = 0.001) but not baseline HbA1c (P = 0.139), age (P = 0.115) or HbA1c response after FM (P = 0.473) as predictive of requiring laser photocoagulation after FM commencement.
Discussion: These data suggest that rapid improvement in HbA1c following FM, in a high-risk population, is not independently predictive of subsequent requirement for laser photocoagulation.
K. Linton: None. F.W. Gibb: None.
