LONGITUDINAL CHANGE IN FORCED EXPIRATORY VOLUME IN HEALTHY, NONSMOKING MEN AND WOMEN - THE BALTIMORE LONGITUDINAL-STUDY OF AGING

Studies of age-associated changes in forced expiratory volume at one s econd (FEV1) have varied in the degree of screening for health and smo king, and have not examined age differences in variability in FEV1. Lo ngitudinal rates of change and variability in. FEV1 among healthy life time-non-smoking White men and women in the Baltimore Longitudinal Stu dy 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 regr ession models. Longitudinal percentile distributions of FEV were calcu lated which reflect age differences in between-subjects variability. T he results show that longitudinal rate of decline in FEV1 is more rapi d in men than women (340 ml/decade in men compared to 240-330 ml/decad e in women), hut similar on a percentage basis (10%) and the differenc e is not statistically significant; FEV1 decline begins in early adult hood and progresses at a relatively constant rate over the adult lifes pan; longitudinal decline in FEV1 in BLSA participants is not statisti cally different from cross-sectional estimates from the BLSA and Crape et al. (1981); and between-subjects variability is greater in men tha n women and increases with age. The results document a relatively stea dy progressive longitudinal decline in FEV1 in healthy non-smoking Whi te adults, as well as age and gender differences in variability in FEV 1, The percentile distribution curves reported here are apparently the first reference values for FEV1 to be derived using longitudinal meth ods that reflect age-specific differences in variability. (C) 1998 Wil ey-Liss, Inc.