Area under the inspiratory flow-volume curve (AIN): Proposed normative values. PLoS One 2024;19(8):e0307966
Date
08/01/2024Pubmed ID
39088417Pubmed Central ID
PMC11293737DOI
10.1371/journal.pone.0307966Scopus ID
2-s2.0-85200103757 (requires institutional sign-in at Scopus site) 1 CitationAbstract
RATIONALE: Area under expiratory flow-volume curve (AEX) has been shown to be a valuable functional measurement in respiratory physiology. Area under inspiratory flow-volume loop (AIN) also shows promise in characterizing upper and/or lower airflow obstruction.
OBJECTIVES: we aimed here to develop normative reference values for AIN, able to ascertain deviations from normal.
METHODS: We analyzed AIN in 4,980 spirometry tests recorded in non-smoking, healthy individuals in the Pulmonary Function Testing Laboratory.
RESULTS: The mean (95% confidence interval, CI), standard deviation and median (25th-75th interquartile range) AIN were 16.05 (15.79-16.31), 9.08 and 14.72 (9.12-21.42) L2·sec-1, respectively. The mean (95% CI) and standard deviation of the best-trial measurements for square root of AIN (Sqrt AIN) were 3.84 (3.81-3.87) and 1.14; 4.15 (4.12-4.18) and 1.03 in men, and 2.68 (2.63-2.72) and 0.72 L·sec-1/2 in women. The mean (standard deviation) of pre- and post-bronchodilator Sqrt AIN were 3.71 (1.17) and 3.81 (1.19) L·sec-1/2, respectively. The mean (95% CI), standard deviation and lowest 5th percentile (lower limit of normal, LLN) of Sqrt AIN/Sqrt AEX (%) were 101.3 (100.82-101.88), 18.7, and 71.8%; stratified by gender, it was 102.2 (101.6-102.8), 18.6, and 72.8% in men, and 98 (96.9-99.2), 18.8, and 68.6% in women, respectively.
CONCLUSIONS: The availability of area under the inspiratory flow-volume curve (AIN) and the derived indices offers a promising opportunity to assess upper airway disease (e.g., involvement of larynx, trachea or major bronchi), especially because some of these measurements appear to be independent of age, race, height, and weight.
Author List
Ioachimescu OC, Stoller JKAuthor
Octavian C. Ioachimescu PhD, MD Vice Chair, Director, Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdolescentAdult
Aged
Area Under Curve
Female
Humans
Inhalation
Male
Middle Aged
Reference Values
Respiratory Function Tests
Spirometry
Young Adult
