Laura J. Reid, Fraser W. Gibb, Helen Colhoun, Sarah H. Wild, Mark W. J. Strachan, Karen Madill, Baljean Dhillon, Shareen Forbes
Continuous subcutaneous insulin infusion (CSII) is associated with reductions in HbA1c compared with multiple daily injections (MDI), but few studies have assessed whether CSII confers subsequent reductions in the risk of microvascular complication. In this issue, Reid et al (https://doi.org/10.1007/s00125-021-05456-w) report that in adults with type 1 diabetes with no or mild diabetic retinopathy, CSII is associated with reduced risk of retinopathy progression over 2.3 years vs those continuing on MDI (n = 204 vs n = 211 adults), with greatest benefits in those with the highest baseline HbA1c. Despite significant HbA1c reductions in the CSII group there was no evidence of early worsening of retinopathy. Reduction in HbA1c from baseline was not associated with diminished retinopathy risk, therefore factors other than HbA1c intrinsic to CSII therapy may drive microvascular risk benefits. Thus, this study provides evidence in a real-world setting that CSII is beneficial in reducing retinopathy progression in type 1 diabetes, particularly when baseline HbA1c is high.