Association between Cardiorespiratory Fitness and Lung Health from Young Adulthood to Middle Age

Abstract

Rationale: Beyond the risks of smoking, there are limited data on factors associated with change in lung function over time.

Objectives: To determine whether cardiorespiratory fitness was longitudinally associated with preservation of lung health.

Methods: Prospective data were collected from 3,332 participants in the Coronary Artery Risk Development in Young Adults study aged 18-30 in 1985 who underwent treadmill exercise testing at baseline visit, and 2,735 participants with a second treadmill test 20 years later. The association between cardiorespiratory fitness and covariate adjusted decline in lung function was evaluated.

Measurements and main results: Higher baseline fitness was associated with less decline in lung function. When adjusted for age, height, race-sex group, peak lung function, and years from peak lung function, each additional minute of treadmill duration was associated with 1.00 ml/yr less decline in FEV1 (P < 0.001) and 1.55 ml/yr less decline in FVC (P < 0.001). Greater decline in fitness was associated with greater annual decline in lung function. Each 1-minute decline in treadmill duration between baseline and Year 20 was associated with 2.54 ml/yr greater decline in FEV1 (P < 0.001) and 3.27 ml/yr greater decline in FVC (P < 0.001). Both sustaining higher and achieving relatively increased levels of fitness over 20 years were associated with preservation of lung health.

Conclusions: Greater cardiopulmonary fitness in young adulthood, less decline in fitness from young adulthood to middle age, and achieving increased fitness from young adulthood to middle age are associated with less decline in lung health over time. Clinical trial registered with www.clinicaltrials.gov (NCT 00005130).

Trial registration: ClinicalTrials.gov NCT00005130.

Keywords: exercise; physical fitness; respiratory epidemiology; respiratory function tests.

Figures

Figure 1.

Mean adjusted decline in lung health (FEV1 and FVC) from peak measurement to Year 20 across sex-specific quartiles of 20-year change in cardiorespiratory fitness stratified by lifetime smoking intensity. Red dots represent mean (with standard error of the mean) decline in lung function for each sex-specific quartile of decline in fitness, and multivariable linear regression lines are superimposed as solid lines with 95% confidence intervals represented as dashed lines. (never smokers, n = 1,585; ≤10 pack-years, n = 685; ≥10 pack-years, n = 465) (FEV1: never smokers, β = 1.91, P < 0.001; ≤10 pack-years, β = 1.27, P = 0.002; ≥10 pack-years, β = 3.17, P < 0.001) (FVC: never smokers, β = 2.04, P < 0.001; ≤10 pack-years, β = 1.47, P = 0.003; ≥10 pack-years, β = 3.15, P < 0.001). All β coefficients are in units of ml/yr decline in FEV1 or FVC per minute decline in treadmill performance such that a higher positive number denotes greater decline in lung function.