Although Chronic Obstructive Pulmonary Disease (COPD) has been considered a disease of Caucasian men, recent data shows mortality rising fastest among Caucasian and African-American women. These differences are partly due to changing smoking habits over time though some suggest that these subgroups may be more susceptible to tobacco smoke. We sought to examine this issue in our population of smokers with COPD.
We performed a retrospective analysis of patients entered into our COPD database between March 2003 and March 2004. Patients were recruited from our clinics and from advertising. At the time of screening, baseline demographics, smoking history, and pre- and post-bronchodilator spirometric data were recorded. We examined the group of patients over age 45 with 20 or more pack-years of smoking, FEV1/FVC <0.70, and a post-bronchodilator FEV1 <80%. Post-bronchodilator results were recorded as percent predicted according to the published estimates of Crapo. We adjusted predicted values for African-Americans by multiplying by 0.88. The estimated loss in lung function per pack-year smoked was calculated using the formula ((100 –(% predicted FEV1))/pack-years). Differences between subgroups were examined using chi-square or t-tests as appropriate.
454 patients were enrolled in the database and 264 met our inclusion criteria. The tableGroupAgePack-YearsFEV1 (%)#Reversible/(%)Δ FEV1(%)/Pack-YearP value (vs. white males)Black females57.146.447.97/17 (41)−1.320.006Black males58.045.055.28/20 (40)−1.130.15White females60.847.453.633/88 (38)−1.150.009White males65.162.051.460/139 (43)−0.94----shows the average age, pack-years smoked, % predicted FEV1, fraction of patients with a bronchodilator response (>12%), and the loss of lung function/pack-year smoked for each subgroup. White males were significantly older (p<0.0007) than the other subgroups and had more pack-years of smoking (p<0.03). There were no differences between the groups in terms of lung function or the number of patients with reversibility to bronchodilator. White males had less loss of lung function/pack-year smoked than white females (p=0.009) and black females (p=0.006).
There are important differences in racial and gender susceptibility to tobacco smoke among patients with COPD. Black females appear to be at highest risk.
COPD remains a major public health problem and mortality continues to increase. African-American female smokers may benefit most from smoking cessation.
J.J. Davis, None.