The impact of heavy passive smoking on arterial endothelial function in modernized Chinese

OBJECTIVES The study evaluated whether heavy exposure to environmental toba cco smoke (passive smoking) might damage arterial function in modernized Ch inese. BACKGROUND Heavy passive smoking is associated With arterial endothelial dy sfunction in Caucasian, but not rural Chinese, subjects. METHODS We studied 20 young (mean age 36.6 +/- 7.0 years) nonsmoking asympt omatic casino workers (9 men) in Macau who were exposed to environmental to bacco smoke for over 8 h/day for at least two years and 20 normal subjects (control subjects). These two groups were carefully matched for age, gender , body mass index (BMI), blood pressure, vessel diameter, cholesterol and g lucose levels. Brachial artery diameter was measured by high-resolution B-m ode ultrasound at rest, after flow increase (causing flow-mediated endothel ium-dependent dilation) and after sublingual nitroglycerin tan endothelium- independent dilator). RESULTS Flow-mediated dilation (mean +/- SD% of diameter changes) was signi ficantly lower in passive smokers (6.6 +/- 3.4%) compared with the controls (10.6 +/- 2.3%) (p < 0.0001). Nitroglycerin-induced dilation of the two gr oups were similar. Upon multivariate analysis, passive smoking exposure was the strongest independent predictor (beta = -0.59; p = 0.0001) for impaire d flow-mediated endothelium-dependent dilation (model R-2 = 0.75, F value = 6.1, p = 0.0001). CONCLUSIONS In modernized Chinese, as in Caucasians, exposure to heavy envi ronmental tobacco smoke causes arterial endothelial dysfunction, a key earl y event in atherosclerosis. This may have serious implications for cardiova scular health in China, currently in a process of rapid modernization. CT A m Cell Cardiol 2000;36:1228-32) (C) 2000 by the American College of Cardiol ogy.