Elevated total cholesterol, the related low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglycerides, and smoking habits are risk factors for cardiovascular disease. The objective of this study was to investigate the influence of habitual smoking on these parameters in 492 hypercholesterolemic men and women, aged between 26 and 66 years. Relative differences between smokers and non-smokers in the mean values of total cholesterol, low-density and hig-density lipoprotein-cholesterol, and triglycerides were 2.2%, 5.5%, -8.1%, and 13.7%, respectively. These differences were statistically significant (P<0.04). Over the entire cohort, including men and women, age did not affect the mean values significantly, except for total cholesterol and triglyceride values in smoking women, which were significantly higher in women over 50 years than in the younger women (P=0.011 and P=0.004). In both men and women, regardless of smoking habits, 43%-59% of subjects exceeded the upper reference range value for low-density lipoprotein-cholesterol (4.9 mmol/l), while 38%-59% exceeded the upper reference range value for triglycerides (2.0 mmol/l) and 82%-91% had values below the lower reference range value for high-density lipoprotein-cholesterol (0.9 mmol/l for men, 1.2 mmol/l for women). Smoking habits hardly influenced the extent to which reference values were exceeded, except for low-density lipoprotein-cholesterol in all subjects (higher percentage for smokers, P=0.041). Similar results were obtained for age, except for triglycerides in smoking women, wich showed high values in 26% of women <50 years versus 50% of women > or = 50 years (P=0.026). In conclusion, smoking has an adverse effect on low-density and high-density lipoprotein-cholesterol, and triglycerides in a hypercholesterolemic population of men and women, regardless of age.