BACKGROUND AND AIMS: We examined the cross-sectional and longitudinal association of arterial stiffness and pressure wave reflection with the ankle-brachial pressure index (ABI) in middle-aged Japanese subjects free of peripheral artery disease (PAD). METHODS: ABI, brachial-ankle pulse wave velocity (baPWV) and radial augmentation index (rAI) were measured annually during the 9-year observation period in 3066 men (42 ± 9 years old) with ABI ≥1.00 at baseline of the study period, and not taking any antihypertensive medication. RESULTS: In the cross-sectional assessments, mediation analysis demonstrated that baPWV showed both direct and indirect (via the rAI) associations with ABI, and rAI showed both direct and indirect (via the heart-arm difference of systolic blood pressure) associations with the ankle-arm difference of systolic blood pressure, both at study baseline and end of study period. Mixed model linear regression analysis of the repeated-measurement data obtained over the 9-year observation period demonstrated that annual increase of baPWV (estimate = 0.73 × 10-4, p < 0.01) and rAI (estimate = 0.33 × 10-3, <0.01) was associated with ABI. When baPWV and rAI were entered into the same model, only baPWV showed a significant longitudinal association with ABI. CONCLUSION: In middle-aged Japanese men free of PAD, arterial stiffness may contribute to ABI directly and via pressure wave reflection. Pressure wave reflection may contribute to ABI directly and, at least in part, via attenuation of peripheral pulse pressure amplification.
BACKGROUND AND AIMS: We examined the cross-sectional and longitudinal association of arterial stiffness and pressure wave reflection with the ankle-brachial pressure index (ABI) in middle-aged Japanese subjects free of peripheral artery disease (PAD). METHODS: ABI, brachial-ankle pulse wave velocity (baPWV) and radial augmentation index (rAI) were measured annually during the 9-year observation period in 3066 men (42 ± 9 years old) with ABI ≥1.00 at baseline of the study period, and not taking any antihypertensive medication. RESULTS: In the cross-sectional assessments, mediation analysis demonstrated that baPWV showed both direct and indirect (via the rAI) associations with ABI, and rAI showed both direct and indirect (via the heart-arm difference of systolic blood pressure) associations with the ankle-arm difference of systolic blood pressure, both at study baseline and end of study period. Mixed model linear regression analysis of the repeated-measurement data obtained over the 9-year observation period demonstrated that annual increase of baPWV (estimate = 0.73 × 10-4, p < 0.01) and rAI (estimate = 0.33 × 10-3, <0.01) was associated with ABI. When baPWV and rAI were entered into the same model, only baPWV showed a significant longitudinal association with ABI. CONCLUSION: In middle-aged Japanese men free of PAD, arterial stiffness may contribute to ABI directly and via pressure wave reflection. Pressure wave reflection may contribute to ABI directly and, at least in part, via attenuation of peripheral pulse pressure amplification.