Childhood asthma and GOLD-defined chronic obstructive pulmonary disease.
BACKGROUND
Current understanding of chronic obstructive pulmonary disease (COPD) is that it results from an interaction of genetic and environmental factors. This study aimed to investigate the strength of association of various known risk factors for COPD.


METHODS
Detailed written questionnaires, full pulmonary function tests and atopy testing were completed in 749 people, aged 25-75 years, recruited from a random population sample. COPD was defined, using Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, as a post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV(1) /FVC) ratio <0.7.


RESULTS
The prevalence of COPD was higher in men (OR 1.7 (95% CI 1.1-2.7)) and increased with increasing age (OR per decade older 2.1 (95% CI 1.7-2.7)). COPD was more frequent in current and ex-smokers and increased with increasing pack years (OR per 10 pack years 1.3 (95% CI 1.1-1.5)). On a logit scale, a diagnosis of asthma as a child conferred a similar risk as an increase in age of 22 years or 62 pack years of cigarette smoking.


CONCLUSIONS
Childhood asthma emerged with the strongest association for GOLD-defined COPD. Possible explanations for this are suggested, including limitations of the current GOLD spirometric definition of COPD, a chance observation because of the high prevalence of both disorders in this population, or alternatively childhood asthma is a risk factor for COPD.
Shirtcliffe
P
P
Medical Research Institute of New Zealand, Wellington, New Zealand. pip.shirtcliffe@mrinz.ac.nz
Marsh
S
S
Travers
J
J
Weatherall
M
M
Beasley
R
R
D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008875:Middle Aged; D001249:Asthma / Q000453:epidemiology / Q000208:ethnology / Q000276:immunology; D001991:Bronchitis / Q000453:epidemiology; D015897:Comorbidity; D018450:Disease Progression; D006969:Hypersensitivity, Immediate / Q000453:epidemiology; D009520:New Zealand / Q000453:epidemiology; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000208:ethnology; D011656:Pulmonary Emphysema / Q000453:epidemiology; D012307:Risk Factors; D012494:Sampling Studies; D012882:Skin Tests; D012907:Smoking / Q000453:epidemiology; D013147:Spirometry; D000095284:Maori People / Q000706:statistics & numerical data; D008297:Male