摘要：Objectives. We investigated associations of smoking and coronary heart disease (CHD) by age. Methods. Data came from the Pooling Project on Diet and Coronary Heart Disease (8 prospective studies, 1974–1996; n = 192 067 women and 74 720 men, aged 40–89 years). Results. During follow-up, 4326 cases of CHD were reported. Relative to never smokers, CHD risk among current smokers was highest in the youngest and lowest in the oldest participants. For example, among women aged 40 to 49 years the hazard ratio was 8.5 (95% confidence interval [CI] = 5.0, 14) and 3.1 (95% CI = 2.0, 4.9) among those aged 70 years or older. The largest absolute risk differences between current smokers and never smokers were observed among the oldest participants. Finally, the majority of CHD cases among smokers were attributable to smoking. For example, attributable proportions of CHD by age group were 88% (40-49 years), 81% (50-59 years), 71% for (60-69 years), and 68% (≥ 70 years) among women who smoked. Conclusions. Among smokers, the majority of CHD cases are attributable to smoking in all age groups. Smoking prevention is important, irrespective of age. Despite decades of attempts to reduce smoking prevalence, 20% of persons living in the United States still smoke, and smoking remains the number one cause of preventable mortality. 1,2 A leading cause of death attributable to smoking is coronary heart disease (CHD). 3 CHD etiology differs across age groups. For instance, relatively more cases of CHD among young adults may be attributable to genetic causes. 4,5 Hence, among young adults, who are at low absolute risk for CHD, smoking may considered a risk factor that does not cause disease until later in life. At the other end of the age scale, research suggests that the relative risk of CHD associated with smoking attenuates in old age. 6 This finding could erroneously suggest that smoking is only a weak risk factor for the elderly and that smoking prevention should therefore be of low priority because quality-of-life issues outweigh the net gain in health. With an increasingly older population, understanding patterns in the strength of risk factors by age is of considerable interest. The incidence of CHD varies considerably by age; it is very low in women younger than 40 years and in men younger than 50 years. 7 For this reason, the statistical power to investigate effects of smoking on CHD in young adults is limited. We pooled the data from 8 prospective cohort studies with information on smoking and potential confounders, including diet, to gain a sufficient sample size to investigate associations between smoking and CHD in subsets of populations defined by age.
