Smoking is associated with higher cardiovascular risk in young women than in men: The Tecumseh Blood Pressure Study

Background: Tobacco smoking is associated with a higher prevalence of atherosclerosis and respiratory disease. Objective To investigate differences between hemodynamic and biochemical findings in smokers and nonsmokers in the two sexes separately in the Tecumseh population. Methods: We studied 851 subjects. They were divided according to smoking habits into group 1, nonsmokers (258 men and 234 women); and group 2, smokers (185 men and 174 women). Results: Unpaired Student's t-tests and nonparametric tests were performed to determine the between-group P-values. Only hematocrit differed significantly between smokers and nonsmokers in both sexes (43.9 ± 0.2 and 44.6 ± 9.3%, P < 0.05 in men; 39.2 ± 0.3 and 40.3 ± 0.3%, P = 0.007 in women, respectively in nonsmokers and smokers). Triglycerides (80.6 ± 3.8 and 99.6 ± 4.3 mg/dl, P < 0.001), left ventricular mass index (95.4 ± 1.9 and 100.0 ± 1.2 g/m², P = 0.008), and posterior wall thickness (9.5 ± 0.1 and 9.71 ± 0.01 mm, P = 0.044) were elevated and high-density lipoproteins were decreased (48.7 ± 0.8 and 44.5 ± 0.9 mg/dl, P < 0.01) only in women smokers. After adjustment for home systolic blood pressure and body mass index the differences in women remained significant except for posterior wall thickness. Conclusion: Tobacco smoking is deleterious to both sexes but it appears to be particularly harmful to women. Our data can, in part, explain why the relative risk of myocardial infarction is higher in women than it is in men.