Aim: The aim of this study was to investigate the potential role of ankle-brachial index (ABI) as a marker of microvascular disease in patients with type 2 diabetes mellitus.
Methods: This study included 126 type 2 diabetic patients (64 male and 62 female) with an age of 66.6+/-5.3 years (mean+/-SD) and diabetes duration of 13.2+/-4.1 years. ABI was measured with a Doppler device. The exclusion criterion was the medial arterial calcification. Patients were also examined for microalbuminuria, retinopathy and peripheral neuropathy.
Results: ABI was significantly lower in patients with microalbuminuria than in those without microalbuminuria (0.91+/-0.17 vs 1.05+/-0.13, P=0.004), in patients with retinopathy than in those without retinopathy (0.91+/-0.18 vs 1.06+/-0.1, P=0.005), as well as in patients with neuropathy than in those without neuropathy (0.94+/-0.17 vs 1.06+/-0.11, P=0.001). Sensitivity and specificity of ABI <0.9 were 48.8% and 87.9% respectively for microalbuminuria, 39.1% and 93% respectively for retinopathy and 47% and 90.7% respectively for neuropathy. In multiple regression analysis, significant predictor of microalbuminuria was diabetes duration (P=0.0014), significant predictor of retinopathy was diabetes duration (P=0.001), while significant predictors of neuropathy were diabetes duration (P=0.001), male sex (P=0.001) and presence of retinopathy (P=0.047).
Conclusion: ABI is significantly lower in patients with than in those without microvascular complications of type 2 diabetes. An ABI <0.9 has a low to modest sensitivity, but a high specificity for the diagnosis of these complications. Our results suggest a potential role for ABI as a surrogate marker of microvascular complications in type 2 diabetic patients.