Female smokers beyond the perimenopausal period are at increased risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis.
BACKGROUND
Recent reports indicate that over the next decade rates of chronic obstructive pulmonary disease (COPD) in women will exceed those in men in the western world, though in most jurisdictions, women continue to smoke less compared with men. Whether female adult smokers are biologically more susceptible to COPD is unknown. This study reviewed the available evidence to determine whether female adult smokers have a faster decline in forced expiratory volume in one second (FEV1) compared with male adult smokers and whether age modifies the relationship between cigarette smoke and lung function decline.


METHODS
A systematic review and a meta-analysis was performed of population-based cohort studies that had a follow-up period of at least 3 years, measured FEV1 on at least two different time points, and presented FEV1 data stratified by gender and smoking status in adults.


RESULTS
Of the 646 potentially relevant articles, 11 studies met these criteria and were included in the analyses (N = 55,709 participants). There was heterogeneity in gender-related results across the studies. However, on average current smokers had a faster annual decline rate in FEV1% predicted compared with never and former smokers. Female current smokers had with increasing age a significantly faster annual decline in FEV1% predicted than male current smokers (linear regression analysis, R2 = 0.56; p = 0.008). Age did not materially affect the rate of decline in FEV1% predicted in male and female former and never smokers (p = 0.775 and p = 0.326, respectively).


CONCLUSIONS
As female smokers age, they appear to experience an accelerated decline in FEV1% predicted compared with male smokers. Future research powered specifically on gender-related changes in lung function is needed to confirm these early findings.
Gan
Wen Qi
WQ
James Hogg iCAPTURE Center for Cardiovascular and Respiratory Research, University of British Columbia, Vancouver, BC, Canada. wgan@mrl.ubc.ca
Man
S F Paul
SF
Postma
Dirkje S
DS
Camp
Patricia
P
Sin
Don D
DD
D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D047648:Perimenopause; D017698:Postmenopause; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology* / Q000503:physiopathology; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology