A high normal ankle--brachial index is associated with electrocardiography-determined left ventricular hypertrophy: the Okinawa Peripheral Arterial Disease Study (OPADS).

Abstract

We aimed to determine if the ankle--brachial index (ABI) increased with age as a result of increased arterial stiffness and wave reflection, and whether this was associated with left ventricular hypertrophy (LVH). An observational cross-sectional study was conducted in 13 396 participants aged 19-89 years who attended a health check-up. Brachial and ankle blood pressures were measured by an automatic oscillometric method. Electrocardiography-determined LVH (ECG-LVH) was defined by computer-interpreted Minnesota codes using resting 12-leads ECG. The mean age of the participants was 53 years (54% women). The prevalence of ECG-LVH was 13%; this was the lowest in participants with normal blood pressure and increased with an increase in the hypertension grade. The ABI was higher in participants with ECG-LVH than in those without (1.13± 0.07 vs. 1.15 ± 0.07, P < 0.001). The prevalence of ECG-LVH was the highest in participants with the highest quartile of ABI (16%), followed by those with the third quartile (14%), second quartile (12%), and the lowest quartile of ABI (9%). The odds ratio for ECG-LVH was significantly higher for participants with a higher quartile of ABI than those with the lowest, before and after adjustment for several covariates. Similar results were observed in sensitivity analysis of individuals with normal kidney function, younger than 65 years, and without diabetes mellitus, performed in order to reduce the influence of a medial arterial calcification-mediated increase in ABI. High ABI is a possible marker of arterial stiffness and/or wave reflection that, even in the normal range, is associated with ECG-LVH.