The association between tonometry-derived measures of arterial stiffness and peripheral arterial disease (PAD) is unclear. Using baseline data from 2847 female and 2614 male participants of the NHLBI-funded MESA study, we conducted linear regression analyses adjusted for age, demographics and risk factors. Ankle-brachial index (ABI) was the dependent variable and measures of large (C1) and small artery elasticity (C2) and total vascular impedance (TVI), all measured from radial artery tonometry, were the independent variables in separate models. In men and women, lower C1 and C2 values were associated with lower ABI. Higher TVI was associated with lower ABI in men and women [P<0.001]. Significant trends for C1, C2 and TVI were observed across clinical strata of ABI (Table
). In pairwise analyses, compared with participants with a normal ABI (1.1 to <1.3), those with ABI <1.1 tended to have significantly lower C2. Additionally, women with high ABI (1.3–1.5) tended to have significantly higher C2 values. Pairwise comparisons of lower and higher ABI groups compared with normal groups did not yield consistent findings for C1. Significantly higher TVI levels with lower ABI group were noted mostly in women (Table
). We observed a continuum of arterial mechanical characteristics across clinical ABI values, indicating that measures of arterial stiffness are significantly associated with ABI and severity of PAD. These results suggest that changes in C2 occur in patients with advanced lower extremity large-vessel atherosclerotic disease. Of note, female participants with high ABI between 1.3–1.5 had a significantly higher C2, arguing against the accepted “non-compressible” or “calcified arterial disease” explanation for high ABI in women. Associations Between ABI and Pulse Wave Analysis Measurements when adjusted for age, cigarette smoking, diabetes, hypertension, and creatinine level