Progression of retinopathy and incidence of cardiovascular disease: findings from the Chronic Renal Insufficiency Cohort Study

Purpose Chronic kidney disease (CKD) patients often develop cardiovascular disease (CVD) and retinopathy. The purpose of this study was to assess the association between progression of retinopathy and concurrent incidence of CVD events in participants with CKD. Design We assessed 1051 out of 1936 participants in the Chronic Renal Insufficiency Cohort Study that were invited to have fundus photographs obtained at two timepoints separated by 3.5 years, on average. Methods Using standard protocols, presence and severity of retinopathy (diabetic, hypertensive or other) and vessel diameter calibre were assessed at a retinal image reading centre by trained graders masked to study participants' information. Participants with a self-reported history of CVD were excluded. Incident CVD events were physician adjudicated using medical records and standardised criteria. Kidney function and proteinuria measurements along with CVD risk factors were obtained at study visits. Results Worsening of retinopathy by two or more steps in the EDTRS retinopathy grading scale was observed in 9.8% of participants, and was associated with increased risk of incidence of any CVD in analysis adjusting for other CVD and CKD risk factors (OR 2.56, 95% CI 1.25 to 5.22, p<0.01). After imputation of missing data, these values were OR=1.66 (0.87 to 3.16), p=0.12. Conclusion Progression of retinopathy is associated with higher incidence of CVD events, and retinal-vascular pathology may be indicative of macrovascular disease even after adjustment for kidney diseases and CVD risk factors. Assessment of retinal morphology may provide important information when assessing CVD in patients with CKD.