Progression of retinopathy with glucagon-like peptide-1 receptor agonists with cardiovascular benefits in type 2 diabetes - A systematic review and meta-analysis

Aims: The effect of Glucagon-like peptide 1 receptor agonists (GLP1 RA) on diabetic retinopathy (DR) remains controversial. Previous reviews combined data from randomized clinical trials (RCTs) with or without cardio-vascular (CV) benefits and did not address confounders, therefore may have generated misleading results. The study aimed to examine the effect of GLP1RA on DR in type 2 diabetes (T2DM) in RCTs with or without CV benefits and distinguish the effect by major confounders. Methods: We conducted electronic searches of multiple databases and a manual search using references lists. We included 13 RCTs examining the effect of GLP1 RA on health outcomes/adverse events including DR or DR complications in T2DM. We performed a random-effects model meta-analysis. Results: GLP1RA was associated with an elevated risk of rapidly worsening DR in four major RCTs with CV benefits in T2DM (OR 1.23, 95 % CI 1.05-1.44). The association between GLP1 RA and DR was significant in subgroups of RCTs with length over 52 weeks (1.2, 1.00-1.43), using placebo as a comparator (1.22, 1.05-1.42). In subgroups with patients who had T2DM <= 10 years (1.19, 0.99-1.42) or with subjects enrolled from multiple countries (1.2, 0.99-1.46), the association appeared to be evident but did not reach statistical significance. Conclusions: GLP1 RA including liraglutide, semaglutide, and dulaglutide are associated with an increased risk of rapidly worsening DR in RCTs with CV benefits. Further data from clinical studies with longer follow-up pur-posefully designed for DR risk assessment, particularly including patients of established DR are warranted.