Longitudinal change in forced expiratory volume in healthy, non-smoking men and women: The Baltimore Longitudinal Study of Aging.

Abstract

Studies of age-associated changes in forced expiratory volume at one second (FEV1) have varied in the degree of screening for health and smoking, and have not examined age differences in variability in FEV1. Longitudinal rates of change and variability in FEV1 among healthy lifetime-non-smoking White men and women in the Baltimore Longitudinal Study of Aging (BLSA) are reported. Longitudinal FEV1 data collected at 2-year intervals for up to 28 yr in 91 men (417 observations) and 14 yr in 82 women (248 observations) were modelled using mixed-effects regression models. Longitudinal percentile distributions of FEV1 were calculated which reflect age differences in between-subjects variability. The results show that longitudinal rate of decline in FEV1 is more rapid in men than women (340 ml/decade in men compared to 240–330 ml/decade in women), but similar on a percentage basis (10%) and the difference is not statistically significant; FEV1 decline begins in early adulthood and progresses at a relatively constant rate over the adult lifespan; longitudinal decline in FEV1 in BLSA participants is not statistically different from cross-sectional estimates from the BLSA and Crapo et al. (1981); and between-subjects variability is greater in men than women and increases with age. The results document a relatively steady progressive longitudinal decline in FEV1 in healthy non-smoking White adults, as well as age and gender differences in variability in FEV1. The percentile distribution curves reported here are apparently the first reference values for FEV1 to be derived using longitudinal methods that reflect age-specific differences in variability. Am. J. Hum. Biol. 10:471–481, 1998. Published 1998 Wiley-Liss, Inc.1 This article is a US Government work and, as such, is in the public domain in the United States of America.