Distribution and reproducibility of spirometric response to ozone by gender and age

• Published in: Journal of applied physiology (1985) 2003-11, Vol.95 (5), p.1917-1925
• Main Authors: Hazucha, Milan J, Folinsbee, Lawrence J, Bromberg, Philip A
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Distribution; Biological and medical sciences; Cross-Sectional Studies; Female; Forced Expiratory Volume; Fundamental and applied biological sciences. Psychology; Gender differences; Humans; Longitudinal Studies; Lungs; Male; Middle age; Middle Aged; Oxidants, Photochemical - administration & dosage; Oxidants, Photochemical - adverse effects; Ozone; Ozone - administration & dosage; Ozone - adverse effects; Reproducibility of Results; Sex Distribution; Spirometry - standards; Spirometry - statistics & numerical data
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00490.2003

Department of Medicine, School of Medicine, and the Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina, Chapel Hill, North Carolina 27599-7310 Submitted 9 May 2003 ; accepted in final form 15 July 2003 Subjects were healthy nonsmoking men ( n = 146) and women ( n = 94) 18-60 yr old. Initially, each subject was exposed for 1.5 h to 0.42 ppm O 3 . Forty-seven individuals were later reexposed twice, 1 wk to several months apart, to 0.4 ppm O 3 . Intermittent exercise utilized in all exposures was adjusted to produce an O 3 dose of 560 ppm x l/m 2 body surface area. The post-O 3 percent change in forced-expiratory volume in 1 s ( %FEV 1 ) decrements of young (18-35 yr) and middle-aged (36-60 yr) men and women differed significantly ( P < 0.05) from normal distribution with values skewed toward larger decrements in younger subjects. The mean %FEV 1 rates were -16.3%, -16.6%, -11.6%, and -6.4%, respectively. The rate of decline with age was 2.5 times higher in young women compared with young men ( P < 0.05). This pattern was reversed in the middle-age cohort. Our data support earlier reports of no significant difference in spirometric response to O 3 between young men and women. The data also confirm that large FEV 1 decrements after O 3 exposure are mostly confined to younger individuals that also show much greater variance in response to repeated exposures than the middle-aged subjects. The majority of subjects remained in their initial category of O 3 sensitivity on retesting after various time lapses. The r value (Spearman) between the first and second and first and third exposure response ranged from 0.544 to 850, depending on classification. However, the mean %FEV 1 differed by as much as six percentage points between exposure days. The yearly loss of responsiveness (0.2% to 0.7%/year) with progressing age determined by cross-sectional analyses was substantially smaller. responsiveness; multiple exposures; sensitivity; young; middle age Address for reprint requests and other correspondence: M. J. Hazucha, Center for Environmental Medicine, Asthma and Lung Biology, Univ. of North Carolina, Chapel Hill, NC 27599-7310 (E-mail: mhazucha{at}med.unc.edu ).