A U-shaped relationship between ankle-brachial index and carotid intima-media thickness in a Chinese population of Inner Mongolia.

AIM

The study was designed to investigate the relationship between ankle-brachial index (ABI) and carotid intima-media thickness (IMT), and provide scientific basis for primary and secondary prevention of atherosclerotic diseases.

METHODS

Participants were recruited for this investigation from Inner Mongolia in China through cluster multistage and random sampling. ABI and carotid-IMT were measured for each subject. Periphery arterial disease (PAD) was defined as an ABI≤0.9 in either leg. ABI values were divided into eight groups at every 0.05, and three carotid-IMT measures were compared among groups separately using analysis of variance (ANOVA) and multivariate linear regression analyses.

RESULTS

The results indicated that the prevalence of PAD among 1236 participants was 1.9%. The average common carotid IMT was 0.70±0.21 mm, internal carotid IMT 0.77±0.24 mm, and carotid artery bifurcation IMT 0.78±0.25 mm. A U-shaped relationship was observed that the values of common carotid, carotid artery bifurcation, and internal carotid arteries IMT were decreased at first then increased as ABI values increased. The U-shaped relationship between ABI and three carotid-IMT measures were remained after adjusting for covariates.

CONCLUSION

The data suggests that carotid IMT values are correlated with ABI values in a U-shaped curve. Increased carotid IMT is correlated with the high prevalence of PAD in population of Inner Mongolia in China.