OBJECTIVETo determine whether blood lipids profile, fibrinogen and viscosity were associated with passive smoking (i. e. environmental tobacco smoke, ETS) in Chinese women who never smoke.

METHODSIn Xi'an, China, a case-control study was carried out on 115 cases of coronary heart disease (CHD) defined by coronary arteriography (CAG) and 208 non-CHD controls confirmed by CAG and/or exercise electrocardiography. Data on exposure to ETS, defined as exposure from cigarettes smoking husband or co-workers or both for at least 5 years, was obtained through standardized interviews. Standard laboratory methods were used and the lipid measurements were under US CDC quality control programs.

RESULTSIn the subjects defined by CAG, the levels of high density lipoprotein cholesterol (HDL-C), HDL2C, apolipoprotein (apo) A1 among passive smokers appeared lower than those in non-passive smokers,but the low density lipoprotein cholesterol (LDL-C), apoB, apoB/A1, fibrinogen, plasma and whole blood viscosity were higher than that in non-passive smokers. There were positive associations of the numbers of coronary arteriosclerosis with the levels of blood lipids,fibrinogen and viscosity. In the non-CHD controls, 81 subjects were not exposed and 127 were exposed to ETS. The P values of t-test for the adjusted (for age, body mass index, present diseases history) means between two groups were listed below: 0.06 (total cholesterol), 0.30 (triglyceride), 0.004 (HDL-C), <0.001 (HDL2-C), < 0.001 (apoA1), 0.009 (apoB), <0.001 (apoB/apoA1), <0.001 (fibrinogen), <0.001 (plasma viscosity), <0.001 and 0.004 [two measures (5.75/s and 230/s) of whole blood viscosity]. The correlation coefficients between cumulative exposure of passive smoking and HDL-C,HDL2-C,apoA1, apoB, apoB/apoA1, fibrinogen, plasma viscosity, and two measures of whole blood viscosity were -0.25, -0.27, -0.30, 0.24, 0.31, 0.32, 0.43, 0.51 and 0.36 (all P<0.01), respectively.

CONCLUSIONPassive smoking could affect blood lipid metabolism, fibrinogen and viscosity in the never smoking women which might contribute to the causation of coronary heart disease.