Comparative Retinopathy Risk in People with Type 2 Diabetes Treated with Post Metformin Second-line Incretin Therapies: Study Based on US Electronic Medical Records

Abstract

Studies have reported conflicting results of the association of incretin-based treatment with the risk of diabetic retinopathy (DR), while the risk of DR in people treated with different antidiabetic drugs (ADD) in the context of glycaemic control in real-world settings is limited. This study aimed to evaluate (1) the risk of developing DR in metformin-treated patients with type 2 diabetes (T2DM) who initiated secondline ADD and (2) if glycaemic control over one-year post-therapy initiation is associated with DR risk during follow-up . From US Electronic Medical Records (EMR), those who received second line DPP-4 inhibitor (DPP-4i), GLP-1 receptor agonist (GLP-1RA), sulfonylurea, thiazolidinedione, or insulin for ≥3 months post-2004 were analysed. Based on 237,133 people with an average of 3.2 years follow-up, compared to people who initiated second-line with sulfonylurea, those with DPP-4i/GLP1RA/thiazolidinedione had 30%/31%/15% significantly lower adjusted risk of developing DR; insulin users had 84% increased risk (all p< 0.01), with significantly better sustainable HbA1c control over one year in incretin groups. This population representative EMR based study suggests that DR risk is not higher in people treated with incretins, versus other ADD, with the benefit of better glycaemic control.