OBJECTIVES: It has been demonstrated that the deleterious effect of smoking on the cardiovascular system is mediated through a decrease in protective HDL cholesterol. In addition, women are more sensitive to the negative effects of smoking, although the exact mechanism underlying this phenomenon is currently unknown. In this study, we evaluated whether smoking habits could modify the association of HDL cholesterol and apolipoprotein A1 (ApoA1) with reverse cholesterol transport (RCT), as measured by cholesterol efflux (CHE), in middle-aged women.
DESIGN: The study group consisted of 39 healthy middle-aged women, 21 non-smokers (age 51.8±2.5 years, BMI 25.1±2.8 kg/m2) and 18 smokers (age 50.5±3.2 years, BMI 24.8±3.5 kg/m2). In addition to all traditional cardiovascular risk factors, CHE from macrophages, labelled during a 48-hour incubation in a medium containing [14C] cholesterol, to plasma acceptors in study subjects was established as a marker of reverse cholesterol transport.
RESULTS: CHE was significantly higher in non-smokers than in smokers (14.22±1.75% vs. 13.17±1.33%; p<0.05). Smoking habit had no effect on the association of HDL with ApoA1 or HDL with CHE. However, in contrast to the strong association of ApoA1 with CHE in non-smokers (r=0.62; p<0.01), no such strong association was found in smokers (r=0.38; n.s.).
MAIN FINDINGS AND CONCLUSION: Based on our results, smoking can alter ApoA1-mediated reverse cholesterol transport in women.