The Prognostic Performance of Lung Diffusing Capacity in Preserved Ratio Impaired Spirometry: An Observational Cohort Study

Hiroaki Ogata; Kachi Sha; Yasuaki Kotetsu; Aimi Enokizu-Ogawa; Katsuyuki Katahira; Akiko Ishimatsu; Kazuhito Taguchi; Atsushi Moriwaki; Makoto Yoshida

doi:10.2147/COPD.S384074

The Prognostic Performance of Lung Diffusing Capacity in Preserved Ratio Impaired Spirometry: An Observational Cohort Study

Int J Chron Obstruct Pulmon Dis. 2022 Oct 28:17:2791-2799. doi: 10.2147/COPD.S384074. eCollection 2022.

Authors

Hiroaki Ogata¹, Kachi Sha¹, Yasuaki Kotetsu¹, Aimi Enokizu-Ogawa¹, Katsuyuki Katahira¹, Akiko Ishimatsu¹, Kazuhito Taguchi¹, Atsushi Moriwaki¹, Makoto Yoshida¹

Affiliation

¹ Department of Respiratory Medicine, National Hospital Organization Fukuoka National Hospital, Fukuoka, Japan.

Abstract

Purpose: Similar to chronic obstructive pulmonary disease (COPD), the diffusing capacity of the lung (D_LCO) might be decreased and associated with poor prognosis in preserved ratio impaired spirometry (PRISm), a clinical entity as a prodromal phase of COPD. The aims of the present study were to evaluate the distributions of D_LCO and to assess the association between D_LCO and mortality among subjects with PRISm.

Patients and methods: We conducted an observational cohort study at the National Hospital Organization Fukuoka National Hospital. We classified the 899 patients ≥ 40 years of age with an assessment of D_LCO into five groups based on spirometry: preserved spirometry, PRISm, mild COPD, moderate COPD, and severe/very severe COPD. The prevalence of low D_LCO (< 80% per predicted) was compared among the five groups. Using PRISm patients with follow-up data, we further investigated the association of low D_LCO with all-cause mortality.

Results: The prevalence of low D_LCO in the PRISm group (58.8%) was significantly higher than that in the preserved-spirometry group (21.8%), the mild-COPD group (23.5%), and the moderate-COPD group (36.0%) (all P < 0.01), and it was comparable to that in the severe/very severe-COPD group (63.2%). The results remained unchanged after adjusting for potential confounders. Among the PRISm subjects, the overall survival rate was significantly lower in the low-D_LCO group than in the preserved-D_LCO group (P < 0.01). The multivariable-adjusted hazard ratio (HR) for all-cause mortality was significantly higher in the low-D_LCO group than in the preserved-D_LCO group (HR = 10.10 (95% confidence interval 2.33-43.89)).

Conclusion: Diffusing capacity was more impaired in PRISm subjects than in those with preserved spirometry or mild to moderate COPD. Regarding PRISm, low D_LCO was a significant risk factor for all-cause mortality. Clinicians should assess D_LCO in the management of PRISm to predict the future risk of overall death.

Keywords: all-cause mortality; chronic obstructive pulmonary disease; diffusing capacity of the lungs; preserved ratio impaired spirometry.

Publication types

Observational Study

MeSH terms

Cohort Studies
Forced Expiratory Volume
Humans
Lung
Prognosis
Pulmonary Diffusing Capacity
Pulmonary Disease, Chronic Obstructive* / diagnosis
Pulmonary Disease, Chronic Obstructive* / epidemiology
Spirometry / methods

Grants and funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.