Title:Impact of Previous Pulmonary Tuberculosis on Chronic Obstructive Pulmonary
Disease: Baseline Results from a Prospective Cohort Study
Volume: 26
Issue: 1
Author(s): Yide Wang, Zheng Li and Fengsen Li*
Affiliation:
- Department of Integrated Pulmonology, The Traditional Chinese Medicine Hospital Affiliated to Xinjiang Medical
University, Urumqi, 830000, P.R. China
- National Clinical Research Base of Traditional Chinese Medicine in Xinjiang,
Urumqi, 830000, P.R. China
Keywords:
Chronic obstructive pulmonary disease, tuberculosis, dose-response relationship, China, cohort study, COPD.
Abstract:
Objective: Pulmonary tuberculosis (PTB) is a significant risk factor for COPD, and Xinjiang,
China, has a high incidence of pulmonary tuberculosis. The effects of tuberculosis history on
airflow restriction, clinical symptoms, and acute episodes in COPD patients have not been reported
in the local population. Besides, the exact relationship between lung function changes in people
with a history of tuberculosis and COPD risk is not clear.
Methods: This study is based on the Xinjiang baseline survey data included in the Natural Population
Cohort Study in Northwest China from June to December, 2018. Subjects' questionnaires,
physical examination, and lung function tests were performed through a face-to-face field survey to
analyze the impact of previous pulmonary tuberculosis on local COPD. Furthermore, we clarified
the specific relationship between pulmonary function decline and the probability of developing
COPD in people with a history of tuberculosis.
Results: A total of 3249 subjects were eventually enrolled in this study, including 87 with a history
of tuberculosis and 3162 non-TB. The prevalence of COPD in the prior TB group was significantly
higher than that in the control group (p-value = 0.005). First, previous pulmonary tuberculosis is an
essential contributor to airflow limitation in the general population and patients with COPD. In all
subjects included, pulmonary function, FEV1% predicted (p-value < 0.001), and FEV1/FVC (%)
(p-value < 0.001) were significantly lower in the prior TB group than in the control group. Compared
to non-TB group, FEV1% prediction (p-value = 0.019) and FEV1/FVC (%) (p-value
= 0.016) were found to be significantly reduced, and airflow restriction (p-value = 0.004) was more
severe in prior TB group among COPD patients. Second, COPD patients in the prior TB group had
more severe clinical symptoms. Compared with no history of tuberculosis, mMRC (p-value
= 0.001) and CAT (p-value = 0.002) scores were higher in the group with a history of tuberculosis
among COPD patients. Third, compared with the non-TB group, the number of acute exacerbations
per year (p-values=0.008), the duration of each acute exacerbation (p-values=0.004), and hospitalization/
patient/year (p-values<0.001) were higher in the group with a history of tuberculosis
among COPD patients. Finally, a dose-response relationship between FEV1/FVC (%) and the
probability of developing COPD in people with previous pulmonary TB was observed; when
FEV1/FVC (%) was < 80.8, the risk of COPD increased by 13.5% per unit decrease in lung function
[0.865(0.805, 0.930)].
Conclusion: COPD patients with previous pulmonary tuberculosis have more severe airflow limitations
and clinical symptoms and are at higher risk for acute exacerbations. Furthermore, lung
function changes in people with a history of tuberculosis were associated with a dose-response relationship
with the probability of developing COPD.
