Characteristics and risk factors for inconsistency between the risk of exacerbations and the severity of airflow limitation in COPD based on GOLD 2017: A retrospective, cross-sectional study

Impact of Previous Pulmonary Tuberculosis on Chronic Obstructive Pulmonary Disease: Baseline Results from a Prospective Cohort Study

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.

Swiss Experience in Therapy With Dual Bronchodilation in Chronic Obstructive Pulmonary Disease in Relation to Self-Reported Physical Functionality

Background

Medical therapy in chronic obstructive pulmonary disease (COPD) usually includes inhaled dual bronchodilation leading not only to an improvement in symptoms but also to an increase in physical performance. However, it remains unknown whether responder rates to dual bronchodilation differ between the Swiss subgroup in comparison to participants of other European countries.

Methods

The non-interventional OTIVACTO trial investigated changes in self-reported physical functioning in COPD patients treated with tiotropium/olodaterol 5/5 µg fixed dose combination for 6 weeks. The cut-off between responder and non-responder was defined as a minimum increase of 10 points using the 10-question physical functioning questionnaire (PF-10) score. We searched for patterns of the responder patient group and compared the results of the whole dataset with the subgroup of Swiss participants.

Results

Compared to the total cohort (n = 7,608), the Swiss participants (n = 94) were predominantly > 65 years of age and had significantly more comorbidities. There were no significant differences according to COPD stage, smoking status, exacerbation rate in the last 12 months and modified Medical Research Council questionnaire (mMRC) score between the total cohort and the Swiss collective. There were no significant differences between the Swiss subgroup and the total cohort with regard to response to the medication in the PF-10 score. In the intragroup comparison, patients with high mMRC score showed significantly higher values in the PF-10 in both groups. The number of exacerbations had no influence on the PF-10 score in the Swiss subgroup but in the total cohort.

Conclusion

In terms of age and number of comorbidities, significant differences were found between the overall patient population and the Swiss participants, having no influence on the success of the medication. The patients suffering from increased dyspnea benefited most from tiotropium/olodaterol treatment (Clinical Trials Registry NCT02720757).