Prior Cardiovascular Disease and Incident Diabetic Retinopathy in Newly Diagnosed Type 2 Diabetes Mellitus

Background/Objectives: To determine whether prior cardiovascular disease (CVD) independently predicts diabetic retinopathy (DR) in adults with newly diagnosed type 2 diabetes mellitus (T2DM). Methods: A retrospective nationwide population-based cohort study was conducted using the Korean National Health Insurance Service database. Adults aged ≥40 years with newly diagnosed T2DM were identified after a 7-year washout period. After 1:1 propensity score matching on age and sex, the analytical cohort comprised 38,812 patients per group. Results: After full covariate adjustment, prior CVD was not independently associated with any DR (HR, 1.01; 95% confidence interval [CI], 0.99–1.04; p = 0.262), NPDR (HR, 1.01; 95% CI, 0.98–1.03; p = 0.605), PDR (HR, 1.01; 95% CI, 0.95–1.06; p = 0.835), or VTDR (HR, 1.00; 95% CI, 0.95–1.06; p = 0.893). Fine–Gray models, accounting for higher all-cause mortality in the prior CVD group after matching (25.2% vs. 22.1%), revealed slightly lower sHR for any DR (sHR, 0.97; 95% CI, 0.95–0.99; p = 0.014) and NPDR (sHR, 0.97; 95% CI, 0.94–0.99; p = 0.005). Conclusions: Prior CVD was not independently associated with incident DR. The lower sHRs may partly reflect competing mortality and should not be interpreted as DR protection. Overall, CVD history was not a criterion for intensified DR screening.