Gender difference in the influence of smoking on arterial wall thickness.

Background: We hypothesized that arterial wall thickening, an early atherogenic alteration, might be associated with smoking differently according to gender, considering the cardiovascular protection of female sex hormones.

Methods And Results: We measured ultrasonographically carotid and femoral intima-media thickness (IMT) in 194 men and 330 women without risk factors other than smoking. In men: (i) current smokers had greater carotid and femoral IMT (P<0.01, P<0.001) and former smokers had greater femoral IMT (P<0.01) than never smokers; (ii) in pooled never, current and former smokers carotid and femoral IMT correlated to current daily smoking (P<0.01) and lifelong smoking (P<0.001); and (iii) carotid and femoral IMT correlated to age in never smokers (P<0.001), current smokers (P<0.01, P<0.001) and former smokers (P<0.01), with greater slopes in current than in former smokers at carotid site (P<0.05) and in current than in never smokers at femoral site (P<0.05). In women: (i) IMT did not differ by smoking status; (ii) in pooled smokers and non smokers femoral IMT correlated to current daily smoking (P=0.01) and to lifelong smoking (P<0.01) with a lower slope than in men (P<0.001), while carotid IMT did not; and (iii) carotid and femoral IMT correlated to age in never smokers (P<0.001), current smokers (P<0.001, P<0.05) and former smokers (P<0.001, P<0.01) with no different slopes.

Conclusion: Smoking-related increase in IMT existed in men but not in women, suggesting a possible protection of female gender from early structural arterial alteration of smoking.