Severity of Diabetic Retinopathy and the Risk of Future Cerebrovascular Disease, Cardiovascular Disease, and All-Cause Mortality

Abstract

Purpose: To determine the relationship between the severity of diabetic retinopathy and the future risk of cerebrovascular accident (CVA), myocardial infarction (MI), congestive heart failure (CHF), and all-cause mortality in patients with type 2 diabetes mellitus.

Design: Retrospective cohort study.

Participants: Patients with type 2 diabetes who underwent diabetic retinopathy screening via fundus photography.

Methods: The relationship between retinopathy status and the 5-year risk of first-time CVA, MI, CHF, and all-cause mortality was investigated using multivariate Cox proportional hazards regressions that controlled for age, gender, race or ethnicity, hemoglobin A1c, duration of diabetes, high-density lipoprotein level, low-density lipoprotein level, history of hypertension, systolic blood pressure, diastolic blood pressure, tobacco use, statin use, body mass index, urine microalbumin-to-creatinine ratio, and estimated glomerular filtration rate.

Main outcome measures: Five-year risk of first-time CVA, MI, CHF, and all-cause mortality.

Results: Seventy-seven thousand three hundred seventy-six patients were included in this study. The average age was 59.8 years with 53.6% male, 31.2% non-Hispanic White, and 41.4% Hispanic patients. Diabetic retinopathy was significantly associated with all outcomes on multivariate analysis. Compared with patients with no retinopathy, those with minimal nonproliferative diabetic retinopathy (NPDR) had a higher risk of CVA (hazard ratio [HR], 1.31; 95% confidence interval [CI], 1.18-1.46), MI (HR, 1.30; 95% CI, 1.15-1.46), CHF (HR, 1.29; 95% CI, 1.19-1.40), and death (HR, 1.15; 95% CI, 1.05-1.25). Similarly, patients with moderate to severe NPDR had a higher risk of each outcome (CVA: HR, 1.56; 95% CI, 1.29-1.89; MI: HR, 1.92; 95% CI, 1.57-2.34; CHF: HR, 1.90; 95% CI, 1.66-2.18, and death: HR, 1.55; 95% CI, 1.32-1.82), as did patients with proliferative diabetic retinopathy (CVA: HR, 2.53; 95% CI, 1.84-3.48; MI: HR, 1.89; 95% CI, 1.26-2.83; CHF: HR, 1.96; 95% CI, 1.47-2.59; and death: HR, 1.87; 95% CI, 1.36-2.56).

Conclusions: Diabetic retinopathy is significantly associated with future risk of CVA, MI, CHF, and death, with higher degrees of retinopathy appearing to carry a heightened risk for each outcome. Retinal information may provide valuable insights into patients' risk of future vascular disease and death.

Keywords: Cardiovascular disease; Cerebrovascular accident; Cerebrovascular disease; Congestive heart failure; Death; Diabetes; Diabetic retinopathy; Mortality; Myocardial infarction; Vascular.