Lung function in our aging population

The chronological age of the Caucasian population and their anthropometrical data have significantly changed within the last five decades. Therefore the question arises whether or not the commonly used reference values of the European Community (ECCS) for lung function may still be accepted today. Since these values were obtained in the 1960s from subjects in a limited age range. For the elderly, the measured values are deduced by extrapolation beyond the range of reference equations which had been obtained in a different population. Therefore decisions concerning elderly and smaller subjects concerning remuneration due to impaired lung function after industrial exposure on the basis of EGKS values are questionable.

Lung function tests were performed by pneumotachography, recording static lung volumes and flow-volume-curves in 262 asymptomatic non smoking males, aged 20 to 90 years. Measurements were performed with the MasterLab, or Pneumo-Screen systems (CareFusion, Höchberg). Results were compared to the reference values of ECCS, SAPALDIA and LuftiBus.

For simplicity analysis of age and height dependence of investigated respiratory parameters (VC, FVC, FEV₁, FEV₁%FVC, PEF, MEF_75,50,25) can be described by linear functions (y = a * height - b * age + c). The forced expiratory vital capacity, FVC, was calculated by FVC = 0.0615*H - 0.0308*A - 4.673; r = 0.78. Mean FVC for younger subjects was found to be 104.7 ± 10.7% of the ECCS reference values and 96.5 ± 11.8% in older subjects. For most parameters investigated linear regressions on age were steeper than described by the ECCS reference values. The regression of lung function to height largely follows the ECCS prescriptions.

Bochum lung function values of younger healthy subjects were higher compared to the reference values of the ECCS and showed a steeper age descent. The alternatively discussed reference values of the SAPALDIA-, or LuftiBus-Study are higher, but do not cover all necessary parameters and/or the age range. A multi centre study for contemporary reference values is recommended.