Abstract
Purpose:
Microvascular changes have increasingly been shown to be associated with the presence of coronary artery disease. Thus, we aimed to determine whether associations existed between diabetic retinopathy (DR) and the severity of coronary artery disease as detected by coronary angiography.
Methods:
The Australian Heart Eye Study examined 1680 participants with suspected coronary artery disease with coronary artery angiography, and six-field retinal photography. Of these, 567 participants were determined to have diabetes from either history or a fasting glucose of ≥7.0mmol/L (126mg/dL). Presence and severity of retinopathy was graded according to the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. Any DR, minimal non-proliferative DR (NPDR) or worse, and mild NPDR or worse were defined as scores of >10, ≥20 and ≥35, respectively. A coronary artery vessel score from 0 to 3, was calculated from the number of vessels with significant stenosis, which was defined as ≥50% of the vessel lumen. After adjusting for age, sex, duration of diabetes, previous heart attack, hypertension, hypercholesterolemia, and current smoking, ordinal regression modeling was used to estimate the association between ETDRS scores and coronary artery vessel scores. Odds ratios describe the risk of having a higher coronary artery score in participants with DR, compared to those without DR.
Results:
The mean age of participants was 63.67 years (Standard Deviation ±10.85 years). 444 (83%) had a history of hypertension, 420 (78.8%) had a history of hypercholesterolemia, and 412 (72.7%) were male. Mild NPDR or worse retinopathy (ETDRS score ≥35) in at least 1 eye was associated with the severity of coronary vascular disease (odds ratio, OR, 1.66; 95% confidence interval, CI, 1.03-2.69). More severe coronary artery disease was associated with presence of any retinopathy in both eyes (OR 1.92, 95% CI 1.19-3.12), bilateral minimal NPDR or worse retinopathy(ETDRS score ≥20) (OR 2.04, 95% CI 1.17-3.56), and bilateral mild NPDR or worse retinopathy(ETDRS score ≥35) (OR 2.14, 95% CI 1.10-4.17).
Conclusions:
Stronger associations were found between bilateral DR at all levels of severity and the severity of coronary artery disease than with unilateral DR. This supports previous findings that microvascular disease, particularly systemic microvascular changes are associated with coronary artery disease.
Keywords: 499 diabetic retinopathy •
461 clinical (human) or epidemiologic studies: natural history