Abstract
Aims/hypothesisWe aimed to compare diabetic retinopathy outcomes in people with type 1 diabetes following introduction of continuous subcutaneous insulin infusion (CSII) therapy with outcomes in people receiving continuing therapy with multiple daily insulin injections (MDI).MethodsThis is a retrospective cohort study using the Scottish Care Information – Diabetes database for retinal screening outcomes and HbA1c changes in 204 adults commenced on CSII therapy between 2013 and 2016, and 211 adults eligible for CSII during the same period but who continued on MDI therapy. Diabetic retinopathy progression (time to minimum one-grade worsening in diabetic retinopathy from baseline grading) was plotted for CSII and MDI cohorts using Kaplan–Meier curves, and outcomes were compared using multivariate Cox regression analysis adjusting for age, sex, baseline HbA1c, blood pressure, cholesterol, smoking status and socioeconomic quintile. Impact of baseline HbA1c and change in HbA1c on diabetic retinopathy progression was assessed within CSII and MDI cohorts.ResultsCSII participants were significantly younger, were from less socially deprived areas, and had lower HbA1c and higher diastolic BP at baseline. There was a larger reduction in HbA1c at 1 year in those on CSII vs MDI (−6 mmol/mol [−0.6%] vs −2 mmol/mol [−0.2%], p < 0.01). Diabetic retinopathy progression occurred in a smaller proportion of adults following commencement of CSII vs continued MDI therapy over mean 2.3 year follow-up (26.5% vs 18.6%, p = 0.0097). High baseline HbA1c (75 mmol/mol [9%]) was associated with diabetic retinopathy progression in the MDI group (p = 0.0049) but not the CSII group (p = 0.93). Change in HbA1c at follow-up, irrespective of baseline glycaemic status, did not significantly affect diabetic retinopathy progression in either group.Conclusions/interpretationCSII was associated with reduced diabetic retinopathy progression compared with continued MDI therapy, and may be protective against diabetic retinopathy progression for those with high baseline HbA1c. Progression of diabetic retinopathy over 3 years was not associated with a change in HbA1c.Graphical abstract
Highlights
Diabetic retinopathy is one of the leading causes of blindness worldwide [1], and prevalence rises with age [2]
People were excluded if the date of commencing continuous subcutaneous insulin infusion (CSII) therapy or completion of diabetes education could not be verified; if baseline or follow-up retinal images had not been taken, or those taken were deemed ungradable for both eyes; if they had been suspended from the retinal screening programme for assessment and potential treatment at ophthalmology clinics; or if they had the maximum severity retinopathy grading (R4) at baseline and could not ‘progress’ to a higher diabetic retinopathy severity grade
We identified 277 multiple daily insulin injections (MDI) control participants who had completed structured diabetes education at a similar time to the CSII cohort but who did not proceed to CSII therapy, largely due to patient preference
Summary
Diabetic retinopathy is one of the leading causes of blindness worldwide [1], and prevalence rises with age [2]. It has been well established, following the landmark DCCT, that good glycaemic control confers long-term benefits to reduce the risk of developing diabetic retinopathy [3]. Relatively few studies have evaluated whether treatment with CSII confers any benefits over MDI in reducing long-term diabetic retinopathy risk in an adult population, or whether there is any increased risk of early diabetic retinopathy worsening following a change in treatment from MDI to CSII
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
