Distinct factors are related to lower limb atherosclerosis in smokers and nonsmokers.

OBJECTIVE: Smoking increases the risk of peripheral artery disease, but the mechanisms are not well established. This study evaluated the association of local circumferential wall tension (CWT), markers of vascular remodeling and stiffness, and traditional risk factors with popliteal and carotid plaques among smokers and nonsmokers. METHODS: Two hundred fifty-two individuals (126 smokers and 126 nonsmokers) underwent clinical, laboratory, and popliteal and carotid ultrasound analysis. Popliteal and carotid CWT measures were calculated in supine and orthostatic positions, and supine position, respectively. RESULTS: Popliteal plaques were more common in smokers than nonsmokers (39 vs. 19%; P < 0.001). Among smokers, popliteal plaques were not related to differences in traditional vascular risk factors. In propensity score-adjusted models, popliteal CWT measures were associated with local plaques in smokers, but not in nonsmokers. Peak orthostatic CWT was the measure showing the most significant association with popliteal plaques (beta ±â€Šstandard error = 0.91 ±â€Š0.28; P = 0.001). Local CWT measures also showed a stronger association with popliteal intima-media thickness among smokers as compared with nonsmokers. By contrast, nonsmokers with popliteal plaques were more likely to have older age, hypertension, diabetes and dyslipidemia, and lower arterial compliance among nonsmokers. Lastly, carotid plaques were not independently related to local CWT among smokers. CONCLUSION: These findings indicate that risk factors for peripheral artery disease may differ between smokers and nonsmokers and further suggest that atherosclerosis in lower limb arteries is directly related to local hemodynamic forces among smokers.

Increased popliteal circumferential wall tension induced by orthostatic body posture is associated with local atherosclerotic plaques.

OBJECTIVE: Lower limb arteries are exposed to higher hemodynamic burden in erectile posture. This study evaluated the effects of body posture on popliteal, carotid and brachial circumferential wall tension (CWT) and investigated the relationship between local CWT and atherosclerotic plaques in subjects with cardiovascular risk factors. METHODS: Two hundred and three subjects (118 women and 85 men) with cardiovascular risk factors (smoking, hypertension or diabetes mellitus) underwent clinical and laboratory analysis and had their blood pressure measured in the arm and calf in supine and orthostatic positions. Arteries were evaluated by ultrasound analysis, while CWT was calculated according to Laplace's law. RESULTS: Among the enrolled participants, 47%, 29% and none presented popliteal, carotid and brachial plaques, respectively. Carotid CWT measurements were not associated with local plaques after adjustment for potential confounders. Conversely, general linear model and logistic regression analyses adjusted for potential confounders demonstrated that peak orthostatic CWT was the only local hemodynamic parameter showing significant relationship with popliteal plaques in the whole sample. In gender-specific analyses, although positively correlated with popliteal plaques in both genders, local peak orthostatic CWT exhibited an independent association with popliteal plaques after adjustment for potential confounders only in women. CONCLUSION: Popliteal CWT measured in orthostatic posture, rather than in supine position, is associated with popliteal atherosclerotic plaques, particularly in women. These findings suggest that erectile posture might play a role in the atherogenesis of leg arteries by modifying local hemodynamic forces and that there may be gender differences in this regard.