Smoking and lung function in elderly men and women. The Cardiovascular Health Study.

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, preclinical, 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 (FEV1) and forced vital capacity and prevalence of low FEV1 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 FEV1 levels were related positively to height and white race and negatively to age and waist girth. Age- and height-adjusted FEV1 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 FEV1 levels similar to never smokers, but FEV1 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.