Usefulness of a Newly Developed Spirometer to Measure Dynamic Lung Hyperinflation following Incremental Hyperventilation in Patients with Chronic Obstructive Pulmonary Disease

Serum periostin reflects dynamic hyperinflation in patients with asthma

Introduction

Dynamic hyperinflation (DH) is sometimes observed and is associated with impaired daily life activities of asthma. We assessed the relationship between DH and asthma biomarkers (blood eosinophil, fractional exhaled nitric oxide (F _eNO) and serum periostin) in patients with asthma.

Methods

Fifty patients with stable asthma were prospectively recruited and underwent blood test, F _eNO measurement, spirometry and metronome-paced tachypnoea (MPT) test to assess DH. In MPT tests, inspiratory capacity (IC) was measured at baseline and after 30 s of MPT with breathing frequencies of 20, 30 and 40 breaths·min^-1. DH was assessed by the decline of IC from baseline, and maximal IC reduction ≥10% was considered as positive DH.

Results

Thirty patients (60%) showed positive DH. Patients with positive DH showed higher serum periostin levels (107.0±30.7 ng·mL^-1) than patients with negative DH (89.7±23.7) (p=0.04). Patients in Global Initiative for Asthma treatment steps 4-5 (n=19) showed higher serum periostin levels (p=0.01) and more severe IC reduction after MPT (p<0.0001) than patients in steps 1-3 (n=31). Maximal IC reduction after MPT was significantly correlated with asthma control test score (r=-0.28, p=0.05), forced expiratory volume in 1 s (r=-0.56, p<0.0001), and serum periostin levels (r=0.41, p=0.003).

Conclusion

Serum periostin may have the possibility to reflect DH in patients with stable asthma.

Metronome-Paced Incremental Hyperventilation May Predict Exercise Tolerance and Dyspnea as a Surrogate for Dynamic Lung Hyperinflation During Exercise

Background

Dynamic lung hyperinflation (DLH) has been evaluated based on decreased inspiratory capacity (IC) during exercise load. However, this is not routinely done in clinical practice. We have developed a convenient method of metronome-paced incremental hyperventilation (MPIH) and reported its usefulness. In the present study, we compared these two methods for evaluating DLH and examined whether our MPIH method can be used to predict DLH during exercise.

Methods

DLH was measured by MPIH and constant load exercise (CLE) in 35 patients with stable COPD. DLH was defined as the most decreased IC (IC_lowest) and the most decreases in IC from IC at rest (-IC_lowest), and we compared between these two methods.

Results

The IC_lowest in CLE and the -IC_lowest in MPIH were significantly lower in emphysema-dominant COPD than in emphysema-nondominant COPD. Both IC_lowest and -IC_lowest showed significant correlations between the two methods (r = 0.67, p < 0.01 and r = 0.44, p < 0.01, respectively). The endurance time of CLE was significantly correlated with IC_lowest following MPIH (r = 0.62, p < 0.01) but not with that obtained by the CLE method. Furthermore, the IC_lowest of MPIH was more significantly correlated with endurance time in emphysema-dominant COPD. Weak but significant correlations between the -IC_lowest obtained by each method and maximum modified Borg scale were observed (MPIH: r = 0.38, p = 0.02; CLE: r = 0.37, p = 0.03).

Conclusion

The MPIH method may be a convenient method to predict exercise tolerance and dyspnea as a clinically useful synergic screening surrogate for DLH during exercise.

Efficacy of tiotropium and olodaterol combination therapy on dynamic lung hyperinflation evaluated by hyperventilation in COPD: an open-label, comparative before and after treatment study

Background: Dynamic lung hyperinflation (DLH) following metronome-paced incremental hyperventilation (MPIH) was reported to be useful for assessment of pathophysiological impairment in patients with chronic obstructive pulmonary disease (COPD), and the effects of tiotropium and olodaterol on DLH following MPIH have not been reported.

Methods: Treatment consisted of administration of tiotropium/olodaterol 5/5 μg inhalation solution (2.5/2.5 μg per actuation) using a soft-mist inhaler once a day. We compared outcomes before and after 8 weeks of treatment. The primary outcome was defined as a decrease in inspiratory capacity (IC) from rest by MPIH, which is an index of DLH. The secondary outcomes were COPD assessment test (CAT), forced expiratory volume in 1 s (FEV₁), and 6-min walking distance (6MWD). In addition, we investigated whether there were correlations between changes with treatment in DLH and FEV₁, 6MWD, and dyspnea.

Results: Thirty-three of the 38 registered patients completed this study. Most of these 33 patients had mild to moderate COPD. Decreasing IC by MPIH was significantly reduced by treatment for 8 weeks, with a mean change of about −0.11 to −0.13 mL (P <0.05). In addition, CAT score, FEV₁, and 6MWD improved with treatment (P <0.05). There were no significant correlations between changes in DLH, FEV₁, 6MWD, or dyspnea with treatment.

Conclusions: The results of this study showed that the combination of tiotropium and olodaterol is effective for improvement of DLH following hyperventilation.

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