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

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.

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.

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 ± standard error = 0.91 ± 0.28; 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.

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.