Shinichi Arizono

Effects of pulmonary rehabilitation in patients with idiopathic pulmonary fibrosis

Background and objective:  Although pulmonary rehabilitation is effective for patients with COPD, its efficacy in patients with IPF is unknown. The purpose of this study was to evaluate the effects of pulmonary rehabilitation in IPF.

Endurance time is the most responsive exercise measurement in idiopathic pulmonary fibrosis.

BACKGROUND: Although pulmonary rehabilitation (PR) has been reported to improve exercise capacity in patients with idiopathic pulmonary fibrosis, it is unknown which exercise measurement is the most responsive for evaluation of PR efficacy. The purpose of this study was to compare the responsiveness of 5 exercise measurements by evaluating the efficacy of PR in subjects with idiopathic pulmonary fibrosis. METHODS: We conducted a prospective observational study in which 53 subjects with idiopathic pulmonary fibrosis were enrolled. The PR group underwent a 10-week out-patient PR program. The control group was observed without any additional intervention, including PR. Five exercise measurements (endurance time [ET], peak work rate, peak oxygen consumption [V̇O2], 6-min walk distance, and incremental shuttle walk distance) were evaluated at baseline and after 10 weeks. The effect size was used for the assessment of responsiveness. RESULTS: In each group, 24 subjects completed the 5 measurements at baseline and after 10 weeks. The changes in ET (PR: 181.6%; control: −8.2%), peak V̇O2 (PR: 7.6%; control: −5.4%), peak work rate (PR: 15.1%; control: −5.1%), 6-min walk distance (PR: 6.0%; control: −3.8%), and incremental shuttle walk distance (PR: 9.1%; control: −5.1%) were significantly different between the groups after 10 weeks (P < .05). In the PR group, ET showed the most striking improvement among the 5 measurements (P < .05), and its effect size was as large as 2.96, whereas those of the others were all < 0.5. CONCLUSIONS: ET is the most responsive exercise measurement for evaluating PR efficacy in patients with idiopathic pulmonary fibrosis.

Quadriceps weakness contributes to exercise capacity in nonspecific interstitial pneumonia

BACKGROUND AND OBJECTIVE It has been shown that peripheral muscle dysfunction is a critical factor in determining exercise intolerance in patients with several chronic lung diseases, including idiopathic pulmonary fibrosis. We hypothesized that exercise capacity would be, at least in part, determined by peripheral muscle dysfunction in patients with fibrotic nonspecific interstitial pneumonia (f-NSIP), another major subtype of fibrotic interstitial lung disease. The aim of the current study was to elucidate the relevance of peripheral muscle dysfunction and its contribution to exercise intolerance in f-NSIP. METHODS The six-minute walk test was evaluated in 30 consecutive patients with f-NSIP along with potential determinants of exercise capacity, including respiratory muscle force and peripheral muscle force. RESULTS Among 30 patients, the median age was 61 years, and 21 were female. Sixteen patients showed significantly decreased quadriceps force (QF), and 17 had significant decreases in maximum expiratory pressure. Exercise capacity and muscle power were clearly related to sex. Adjusted for sex, QF showed a significant relation to exercise capacity measured by six-minute walk distance (6MWD), whereas pulmonary function parameters such as vital capacity showed marginal correlations. In stepwise multiple regression analysis, only QF was an independent predictor of 6MWD. CONCLUSIONS Quadriceps weakness is often observed in patients with f-NSIP. It seems that QF significantly contributes to exercise capacity in this population.

Exercise hypoxaemia as a predictor of pulmonary hypertension in COPD patients without severe resting hypoxaemia

Pulmonary hypertension (PH) in COPD is associated with morbidity and mortality. Previous studies showed a relationship between resting hypoxaemia and PH, but little is known about the relationship between exercise hypoxaemia and PH in COPD without resting hypoxaemia.

The COPD assessment test and St George's Respiratory Questionnaire: are they equivalent in subjects with COPD?

Background The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is a short questionnaire that has facilitated health status measurements in subjects with COPD. However, it remains controversial as to whether the CAT can be used as a suitable substitute for the St George’s Respiratory Questionnaire (SGRQ). This study investigated the reliability and score distributions of the CAT and SGRQ and evaluated which factors contributed to health status for each questionnaire. Methods A total of 109 consecutive subjects with stable COPD from a single center were enrolled in this study. Each subject completed pulmonary function tests, exercise tests, and the following self-administered questionnaires: the Baseline Dyspnea Index, the Hospital Anxiety and Depression Scale, the CAT, and SGRQ. Results Internal consistencies of CAT and SGRQ total scores were both excellent (Cronbach’s α coefficients =0.890 and 0.933). Statistically significant correlations were observed between CAT and SGRQ total scores (R=0.668, P<0.001). Correlations of CAT scores with parameters related to pulmonary function, dyspnea, exercise performance, and psychological factors were inferior to correlations with those parameters with SGRQ total scores. Both multiple regression analyses and principal component analyses revealed that there were slight differences between SGRQ total scores and CAT scores. Conclusion The CAT is similar to SGRQ in terms of discriminating health status. However, we demonstrated that what is assessed by the CAT may differ slightly from what is measured by SGRQ.