Factors Associated with Lung Function Decline in Patients with Non-Tuberculous Mycobacterial Pulmonary Disease

Abstract

BackgroundThere is paucity of risk factors on lung function decline among patients with non-tuberculous mycobacteria (NTM) pulmonary disease in literature.MethodsPatients with NTM pulmonary disease between January 2000 and April 2011 were retrospectively selected. Sixty-eight patients had at least two pulmonary function tests within a mean follow-up period of 47 months.ResultsSixty-eight patients were included. They had a median age of 65 years and 65% had impaired lung function (Forced expiratory volume in 1 second [FEV1] <80% of predicted value). The mean FEV1 decline was 48 ml/year. By linear regression, younger age (beta: 0.472, p<0.001), initial FEV1>50% of predicted value (beta: 0.349, p = 0.002), male sex (beta: 0.295, p = 0.018), bronchiectasis pattern (beta: 0.232, p = 0.035), and radiographic score >3 (beta: 0.217, p = 0.049) were associated with greater FEV1 decline. Initial FEV1>50% of predicted value (beta: 0.263, p = 0.032) was also associated with greater FVC annual decline, whereas M. kansasii pulmonary disease was marginally associated with greater annual FVC decline (beta: 0.227, p = 0.062).ConclusionsNTM pulmonary disease is associated with greater decline in lung function in patients who are young, male, with bronchiectasis, and with a high radiographic score. Special attention should be given to patients with these risk factors.

Nontuberculous Mycobacterial Infection Is Associated with Increased Respiratory Failure: A Nationwide Cohort Study

“…Lee et al found a substantial decline in lung function in young NTM patients. [26]. Their findings are consistent with our findings.…”

Impact of pulmonary nontuberculous mycobacterial treatment on pulmonary function tests in patients with and without established obstructive lung disease

“…Alternatively, antibiotic therapy for pulmonary NTM may not sufficiently control the inflammation or maintain airway structure and function, and progressive airflow limitation may be the natural progression of disease. In order to accurately explore this issue, a larger cohort and longer observation period is necessary, including substantial numbers of patients in all groups (asthma, COPD, ‘normal’), as well as detailed information on both the nature and extent of radiological lung disease …”

“…Disease is frequently chronic despite prolonged multi‐drug therapy, secondary to difficulty in tolerating intensive therapy, an inability to eradicate the infection (sometimes due to drug resistance), and recurrence after apparently successful therapy . It is therefore important to identify patients at greater risk for clinical deterioration and provide optimal therapy to those patients …”

“…In patients without known pre‐existing lung disease, pulmonary NTM could initiate the development of PFT abnormalities. A rapid decrease of forced expiratory volume in 1 s (FEV1) has been described in younger pNTM patients with good baseline lung function in the presence of abronchiectatic radiological pattern and worse radiographical scores . Gas trapping and gas exchange abnormalities have been reported in patients with pulmonary Mycobacterium avium‐intracellulare complex (MAC) infection and no known predisposing lung disease …”

Nutritional Indicators are Correlated with the Radiological Severity Score in Patients with <i>Mycobacterium avium</i> Complex Pulmonary Disease: A Cross-sectional Study

“…The effects of disease progression on the amount of muscle in patients with MAC pulmonary disease are not well recognized. We did not evaluate whether the muscle function, such as the grip strength, was decreased in the MAC patients; however we hypothesized that a decrease in the amount of muscle and the attenuation of muscle strength influence the patient's pulmonary function and the quality of life as the disease progresses (13,14).…”