6.2 IMPACT OF CHANGES IN SMOKING BEHAVIOUR BETWEEN ADOLESCENCE AND YOUNG ADULTHOOD ON ARTERIAL STIFFNESS IN YOUNG ADULTS. THE NORTHERN IRELAND YOUNG HEARTS PROJECT

Abstract

Purpose: to investigate 1) the extent to which young adults who started smoking during adolescence and persisted doing so during young adulthood (‘persistent smokers’–PS), and those who started smoking in young adulthood only (‘starters’–SS) had greater aorto-iliac PWV than never smokers (NS); and 2) whether any such differences could be explained by greater levels of inflammation and/or endothelial dysfunction (ED) associated with smoking. Methods: We studied 408 young adults (age 22.6±1.6yr; 209 women) from the NIYHP in whom PWV and plasma levels of inflammation (i.e. CRP and fibrinogen) and ED (i.e. vWF and tPA-antigen) were measured during young adulthood, and smoking status was assessed during adolescence (age 15) and young adulthood. Data were analysed using linear regression with adjustments for potential confounders and/or mediators. Results: After adjustment for age, sex, height and MAP, and other lifestyle risk factors, PS, but not SS, had higher levels of PWV compared with NS [+0.20m/s (95%CI: 0.07; 0.33), p=0.003, and −0.02m/s (−0.13; 0.08), p=0.667, respectively]. Further adjustments for inflammation and ED did not materially attenuate the differences between PS and NS [to +0.19m/s (0.06; 0.33), p=0.006], despite the fact that PS had higher levels of inflammation [+0.29 SD (0.05; 0.52), p=0.017] and ED [+0.20 SD (0.01; 0.39), p=0.037]. Conclusion: Persistent smoking between adolescence and young adulthood adversely impacts on arterial stiffness, as well as on levels of inflammation and endothelial-dysfunction. However, these pathophysiological mechanisms did not explain the increased arterial stiffness related to persistent smoking.