Tracking of lung function parameters and the longitudinal relationship with lifestyle.

The purpose of this study was to analyse tracking (i.e. relative stability over time/predictability of future values by early measurements) of lung function parameters and their longitudinal relationship with lifestyle (smoking, alcohol consumption, daily physical activity, neuromotor and cardiopulmonary fitness, and dietary intake of retinol and polyunsaturated fatty acids (PUFA)). Data were obtained from the observational Amsterdam Growth and Health Study, a longitudinal study with six repeated measurements between ages 13-27 yrs (n=167). The statistical analyses were carried out with generalized estimating equations. The following "stability" coefficients were found: for forced vital capacity (FVC) in males 0.66 (95% confidence interval (CI): 0.54-0.77) and in females 0.51 (95% CI: 0.43-0.60); for forced expiratory volume in one second (FEV1) in males 0.65 (95% CI: 0.50-0.80), in females 0.53 (95% CI 0.46-0.60); for peak expiratory flow (PEF) in both males and females 0.41 (95% CI: 0.31-0.51). Positive relationships were found between alcohol consumption and FVC and FEV1 and between neuromotor fitness and PEF and (only for males) with FVC and FEV1. Physical activity was inversely related to PEF and the intake of PUFA positively related to FVC and FEV1. Smoking was related to a decrease in FVC and FEV1; changes in physical activity positively correlated to changes in FVC. In conclusion, high to moderate stability/tracking was observed for forced vital capacity and forced expiratory volume in one second; for peak expiratory flow it was slightly lower. Preventive strategies regarding improvements of lung function should focus on smoking cessation and improving daily physical activity.