Smoking and lung function in elderly men and women: the Cardiovascular Health Study

Cigarette smoking appears to reduce lung function among the elderly. Smoking is already known to impair lung function in younger adults. Because smokers are more likely to die prematurely or to stop smoking when they become ill, elderly smokers may be a healthy subset of an initially larger cohort of smokers. Among 5,201 people over 65, 10% of the white men were current smokers, 19% of the black men were current smokers, 13% of the white women were current smokers and 17% of the black women were current smokers. Over 50% of the men were former smokers and about 25% of the women were former smokers. People who had never smoked had better lung function than current and former smokers. Lung function among people who quit before age 40 was similar to that of never smokers. Among former smokers, lung function declined as age at quitting increased. Because poor lung function is associated with cardiovascular disease and lung cancer, elderly smokers should be encouraged to quit.
Objective.--To investigate relationships between cigarette smoking and pulmonary function in elderly men and women. Design.--Cross-sectional analysis of baseline data from a prospective, population-based study of risk factors, proclinical, and overt cardiovascular and pulmonary disease. Setting.--Defined communities in Forsyth County, North Carolina; Pittsburgh, Pa; Sacramento County, California; and Washington County, Maryland. Population.--A total of 5201 noninstitutionalized men and women 65 years of age and older. Main Outcome Measures.--Pulmonary function; means of forced expiratory volume in 1 second [FEV.sub.1]) and forced vital capacity and prevalence of low [FEV.sub.1] levels. Results.--Prevalence of cigarette smoking was 10% to 20% and higher in women than men and in blacks than whites. Forced vital capacity and [FEV.sub.1] levels were related positively to height and white race and negatively to age and waist girth. Age- and height-adjusted [FEV.sub.1] means were 23% and 18% lower in male and female current smokers, respectively, than in never smokers but not reduced in never smokers currently living with a smoker. Smokers who quit before age 40 years had [FEV.sub.1] levels similar to never smokers, but [FEV.sub.1] levels were lower by 7% and 14% in smokers who quit at ages 40 to 60 years and older than 60 years, respectively. Lung function was related inversely to pack-years of cigarette use. Prevalence rates of impaired lung function were highest in current smokers and lowest in never smokers. Regression coefficients for the smoking variables were smaller in persons without cardiovascular or respiratory conditions than in the total cohort. Conclusions.--Cigarette smoking is associated with reduced pulmonary function in elderly men and women. However, smokers who quit, even after age 60 years, have better pulmonary function than continuing smokers. (JAMA. 1993;269:2741-2748)