Diabetic retinopathy: A predictor of coronary artery disease

BackgroundDiabetes mellitus is a vascular disease with many microvascular manifestations as retinopathy and macrovascular complications as coronary artery disease. A large number of diabetics with retinopathy may have unidentified coronary artery disease.ObjectiveEvaluate whether diabetic retinopathy is a valid predictor of coronary artery disease.Study designCross section study.Patients and methodsThe study included 60 male patients chosen randomly from diabetic and ophthalmologic outpatient clinics. Twenty patients had type 2 diabetes mellitus with nonproliferative retinopathy, 20 patients with proliferative diabetic retinopathy and 20 patients with type 2 diabetes mellitus without retinopathy. All studied cases were not previously identified as coronary artery disease. Clinical examination stressed on conventional cardiovascular risk factors; duration, degree of control of hyperglycemia and erectile failure. Lipogram, urinary albumin excretion, resting, exercise ECG and echocardiography were carried out. All patients were subjected to fundus examination for evaluation of diabetic retinopathy and duplex ultrasound to assess carotid intimal medial thickness. Coronary angiography was undertaken for all cases.ResultsThere was no significant difference regarding age, BMI and blood pressure between the groups. However, duration of diabetes, erectile dysfunction and neuropathy revealed significant difference between different groups particularly the proliferative in relation to the nonproliferative diabetic group. Hypertriglyceridimia, urinary albumin excretion and serum cholesterol differ significantly between the studied groups. The ECG, echocardiography showed insignificant differences. Carotid intima media thickness showed an insignificant difference when comparing the three studied groups, however diabetic retinopathy group with coronary artery stenosis revealed a significant increase in carotid media thickness. Evidence of coronary artery stenosis was present in 80% of the proliferative diabetic retinopathy group and in 70% of the nonproliferative diabetic retinopathy group but was not present in nonretinopathic diabetic group. The stenotic lesions were involving one or two vessels. No one had left main disease.ConclusionDiabetic retinopathy is a good predictor of coronary artery disease that exceeds the conventional risk factors. Diabetics with retinopathy would benefit from early coronary angiography and diabetic retinocoronary clinics are warranted.