title: Inspiratory resonant frequency of forced oscillation technique as a predictor of the composite physiologic index in interstitial lung disease.
abstract: The composite physiologic index (CPI), which is derived from FEV1, FVC, and diffusing capacity, has been developed to predict the extent of fibrosis on high-resolution computed tomography (HRCT). However, the relevance to the forced oscillation technique (FOT) is not fully understood. We hypothesized that FOT would independently predict the CPI in interstitial lung disease (ILD). In this cross-sectional study we assessed the relationship between pulmonary function tests, forced oscillatory parameters, and the degree of fibrosis in ILD. Spirometry, evaluation of diffusing capacity for carbon monoxide, and the broadband frequency FOT were performed in 93 patients with a clinical/HRCT diagnosis of ILD. The CPI was calculated and fibrosis extent was measured by HRCT and scored. Univariate analyses revealed that, of the forced oscillatory parameters, inspiratory resonant frequency best correlated with FVC, FEV1, diffusing capacity, CPI, and fibrosis score. In multiple regression analyses, CPI was independently predicted by inspiratory resonant frequency and fibrosis score (model R(2)=0.405, p<0.0001).
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, 4-27-1 Kita-Ando, Aoi, Shizuoka, 420-8527, Japan. Electronic address: mfujii74@gmail.com.
authors.forename: Masato
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, 4-27-1 Kita-Ando, Aoi, Shizuoka, 420-8527, Japan. Electronic address: toshihiro-shirai@i.shizuoka-pho.jp.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Shirai
authors.affiliation: Second Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. Electronic address: mori.kazutaka@gmail.com.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Mori
authors.affiliation: Second Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. Electronic address: masa.mikam@gmail.com.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mikamo
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, 4-27-1 Kita-Ando, Aoi, Shizuoka, 420-8527, Japan. Electronic address: sisidiba@gmail.com.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Shishido
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, 4-27-1 Kita-Ando, Aoi, Shizuoka, 420-8527, Japan. Electronic address: takefumi-akita@i.shizuoka-pho.jp.
authors.forename: Takefumi
authors.initials: T
authors.lastname: Akita
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, 4-27-1 Kita-Ando, Aoi, Shizuoka, 420-8527, Japan. Electronic address: cqn00563@nifty.com.
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital, 4-27-1 Kita-Ando, Aoi, Shizuoka, 420-8527, Japan. Electronic address: kazuhiro-asada@i.shizuoka-pho.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Asada
authors.affiliation: Second Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. Electronic address: suda@hama-med.ac.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004646:Emphysema / Q000209:etiology / Q000473:pathology; D005260:Female; D005355:Fibrosis / Q000209:etiology / Q000473:pathology; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D013147:Spirometry; D015898:Tomography Scanners, X-Ray Computed; D055815:Young Adult
keywords: Composite physiologic index; Fibrosis; Forced oscillation technique; Interstitial lung disease; Resonant frequency