Prior TB, smoking, and airflow obstruction: a cross-sectional analysis of the Guangzhou Biobank Cohort Study.
BACKGROUND
Prior pulmonary TB has been shown to be associated with a higher risk of airflow obstruction, which is the hallmark of COPD, but whether smoking modifies this relationship is unclear. We investigated the relationships between prior TB, smoking, and airflow obstruction in a Chinese population sample.


METHODS
Participants in the Guangzhou Biobank Cohort Study underwent spirometry, chest radiography, and a structured interview on lifestyle and exposures. Prior TB was defined as the presence of radiologic evidence suggestive of inactive TB. Airflow obstruction was based on spirometric criteria.


RESULTS
The prevalence of prior TB in this sample (N = 8,066, mean age: 61.9 years) was 24.2%. After controlling for sex, age, and smoking exposure, prior TB remained independently associated with an increased risk of airflow obstruction (odds ratio = 1.37; 95% CI, 1.13-1.67). Further adjustment for exposure to passive smoking, biomass fuel, and dust did not alter the relationship. Smoking did not modify the relationship between prior TB and airflow obstruction.


CONCLUSIONS
Prior TB is an independent risk factor for airflow obstruction, which may partly explain the higher prevalence of COPD in China. Clinicians should be aware of this long-term risk in individuals with prior TB, irrespective of smoking status, particularly in patients from countries with a high TB burden.
Lam
Kin-bong Hubert
KB
Institute of Occupational and Environmental Medicine, University of Birmingham, UK.
Jiang
Chao Qiang
CQ
Jordan
Rachel E
RE
Miller
Martin R
MR
Zhang
Wei Sen
WS
Cheng
Kar Keung
KK
Lam
Tai Hing
TH
Adab
Peymané
P
D000402:Airway Obstruction / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D013902:Radiography, Thoracic; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D013147:Spirometry; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000150:complications* / Q000453:epidemiology