Non-linear association between ankle-brachial pressure index and prevalence of silent cerebral infarction in Japanese patients with type 2 diabetes.

Objective: Patients with peripheral artery disease (PAD), defined as having low ankle-brachial pressure index (ABI), have increased risk for incident stroke compared with those without PAD. We aimed to reveal whether ABI abnormality, especially high ABI is associated with prevalent silent cerebral infarction (SCI) in type 2 diabetic patients.

Methods: We studied 538 Japanese type 2 diabetic patients, 227 women and 311 men, with a mean [±SD] age of 64±11 years. All patients underwent cranial magnetic resonance imaging (MRI). Values of ABI were classified as low (<0.9), normal (0.9≤ and <1.3), and high (1.3≤). Logistic regression model was used to calculate odds ratio and 95% confidence interval (95% CI) for prevalent SCI.

Results: The mean ABI among the overall 538 patients was 1.09±0.16. Low and high ABI values were found in 52 (9.7%) and 33 (6.1%) patients, respectively. SCI was detected in 297 (55.2%) patients. The prevalence in patients with low, normal, and high ABI values were 88.5%, 49.7%, and 78.8 (p<0.001), respectively. In the multivariate logistic regression analysis, both patients with high and low ABI were significantly increased risk of prevalent SCI (odds ratio 4.53, 95% CI 1.67-12.34, p=0.003 and odds ratio 3.50, 95% CI 1.50-10.29, p=0.005), independently of other traditional cardiovascular risk factors, than those with normal ABI.

Conclusions: Both high and low ABI may be strongly associated with prevalent SCI in Japanese patients with type 2 diabetes.