Abnormally Low or High Ankle-Brachial Index Is Associated With the Development of Diabetic Retinopathy in Type 2 Diabetes Mellitus

Although some studies have reported an association between peripheral artery disease (PAD) and diabetic retinopathy (DR) in patients with diabetes, whether or not a causal relationship exists is unknown. The aim of this study was to investigate whether PAD, as indicated by an abnormally low or high ankle-brachial index (ABI), is associated with the development of DR in patients with type 2 diabetes mellitus (DM) without DR. We enrolled 414 (221 men and 193 women) patients with type 2 DM who underwent ABI measurements at our outpatient clinic. PAD was defined as an abnormally low (<0.9) or high (≥1.3) ABI in either leg, and DR was defined as being non-proliferative or proliferative. Of the enrolled patients, 69 (16.7%) had an ABI <0.9 or ≥1.3. The median follow-up period was 23 (15-40) months, during which 74 (17.9%) patients developed DR. In multivariate analysis, an ABI <0.9 or ≥1.3 was independently associated with the development of DR (vs. ABI ≥0.9 to <1.3; hazard ratio, 2.186; 95% confidence interval, 1.261 to 3.789; p = 0.005). An abnormal ABI was associated with the development of DR in our patients with type 2 DM without DR.