Acute exposure to environmental tobacco smoke reduces HDL-C and HDL2-C

Background. Chronic environmental tobacco smoke (ETS) exposure increases individuals risk of coronary artery disease by reducing high-density lipoprotein cholesterol (HDL-C). Currently, there is limited research on the acute effects of ETS on HDL-C. This study examined the acute influence of ETS on HDL-C and its subfractions. Methods. Twelve male subjects (25.7 ± 3.0 years) were examined to determine the influence of an acute 6-h exposure to ETS on lipid and lipoprotein levels. Baseline blood samples were drawn before ETS exposure from an antecubital vein at 6 am, 2 pm, and 10 pm. The following day, subjects were exposed to 6 h of ETS, approximately 4–10 pm. Blood was again collected at 8, 16 and 24 h following ETS exposure. Blood was assayed for total cholesterol (TC), HDL-C and its subfractions HDL2-C and HDL3-C. Results. As a result of ETS exposure, HDL-C and HDL2-C levels were significantly reduced by 18% and 37%, respectively. This effect was sustained, with a decrease in HDL-C of 13% and HDL2-C of 28% still evident at 24-h post-exposure. TC was unchanged (pre- 187.3 ± 41.6 and post- 187.0 ± 46.3); however, there were significant decreases in the TC/HDL-C and HDL2-C/HDL3-C ratios by 16% and 29%, respectively, which were sustained for 24 h. Conclusions. The findings of this study demonstrate that a 6-h exposure has a negative impact on lipid and lipoprotein profiles and that these levels remained depressed for at least 24 h.