Pulmonary function between 40 and 80 years of age.
Spirometry is the most frequently performed lung function test. To determine a normal range of spirometry results, reference formulas are used. Predicted values play an important role in establishing whether the volumes measured in an individual fall within a range to be expected in a healthy person of the same gender, height, and age. Such standards enable to assess the development of the respiratory system in the youth, the early recognition of the influence of a disease on the respiratory system and the influence of environmental factors on lung function. The objective of the present study was to estimate lung function prediction equations and to identify appropriate normal reference values for the Lublin Region local population of adults. We addressed the issue by analyzing the data from a lung function screening program conducted in the Lublin Region of Poland. Pulmonary function of adults aged 40-80 years was assessed from the measurements of forced vital capacity (FVC) and forced expired volume in the first second (FEV(1)) in 136 adults. Reference values of FVC and FEV(1) for females and males were calculated by linear multiple regressions with age and height used as predictors. Different equations were compared to show their reliability when applied to the local population. The results were as follows. In females, the mean FEV(1) was 2.856 +/-0.534 (L) (113.7 +/-14.3%) and the mean FVC was 3.517 +/-0.662 (L) (118.5 +/-14.1%), in males, 3.913 +/-0.773 (L) (110.9 +/-15.1%), 4.922 +/-0.941 (L) (112.1 +/-14.1%), respectively. The estimated prediction equations were: for the FVC - for females - FVC (L) = 0.0528 (height) - 0.0262 (age) - 3.676 and for males - FVC = 0.0756 (height) - 0.0649 (age) - 4.904; and for the FEV(1) - for females - FEV(1) (L) = 0.0378 (height) - 0.0282 (age) - 1.799 and for males - FEV(1) (L) = 0.0553 (height) - 0.0553 (age) - 2.874. Units are years for age and centimeters for height. In conclusion, the analysis of the lung function data showed that there were significant difficulties in determining the appropriate reference values of FEV(1) and FVC. The predicted FEV(1) and FVC values derived from equations based on the ECSC (1) reference populations are considerably lower than those calculated in the present study, re-emphasizing the need to be cautious when applying the ECSC reference values for the local Lublin population. There seems to be a need for a constant refinement of spirometric standards.