ACTA BIOLOGICA SLOVENICA LJUBLJANA 2002 Vol. 45, Št. 1: 31 - 38 Ventilatory and anthropometric variables in healthy f emale students from the University of Ljubljana Ventilacijski in antropometrični parametri zdravih študentk Univerze v Ljubljani Dorjana ZERBO-ŠPORIN', Matjaž FLEŽAR2, Marija ŠTEFANČIČ3 1 Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia; E-mail: dorjana.zerbos@lek.si (Corresponding person) 2 Clinical department of Pulmonary Diseases and Allergies, SPS Interna! Clinics, Clinical center Ljubljana, SI-4204 Golnik, Slovenia 3 Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia Abstract. Forced expiratory vita! capacity (FEVC) and forced expiratory volume in the first second (FEV 1 ) were measured in healthy, non-smoking female students from the University of Ljubljana. The sample included 86 students, none active in sports, ranging in age from 18-23 years. The results were analysed in terms of anthropometric variables, and regression equations were deri ved. Comparisons were made with Europaean Respiratory Society (ERS) prediction equations derived from non-Slovenian populations, commonly used in our medica! practice. The ERS and our equations predict significantly different values for FEVC and insignificantly for FEV 1 • According to comparisons of r2 and SD of residuals, we presumed that newly deri ved equations can be better predictors of ventilatory parameters for SI ovene female students population. Keywords: students, female, physiology, ventilation, spirometry, anthropometry, vita! capacity, forced expiratory volume. Izvleček. Pri zdravih študentkah nekadilkah, ki se s športom ne ukvarjajo aktivno, smo merili forsirano ekspiratorno vitalno kapaciteto (FEVC) in forsirani ekspiratorni volumen l (FEV 1 ). Vzorec je obsegal 86 študentk ljubljanske universe, starih od 18 do 23 let. Iz izmerjenih antropometričnih parametrov smo izpeljali dve regresijski enačbi za izračun FEVC in FEV, Rezultate smo primerjali z rezultati Evropskega respiratornega združenja (ERS), ki se običajno uporabljajo v medicinski praksi. Izmerjene vrednosti FEVC značilno in vrednosti FEV 1 neznačilno presegajo predvidene evropske standarde. Smatramo, da so za slovensko žensko populacijo naše predikcijske enačbe primernejše, zato priporočamo uporabo lastnih standardov. Ključne besede: študentke, fiziologija, spirometrija, antropometrija, vitalna kapaciteta, forsirani ekspiratorni volumen. 32 Acta Biologica Slovenica, 45 (1), 2002 Introduction Lung volumes and spirometric tests are routinely used to evaluate the normality of respiratory functions. This is achieved by comparing laboratory measured values with those predicted from multiple regression equations that have been developed ona reference sample; the equations frequently use age and body height as independent or predictor variables (WITHERS & al. 1989a, BECKLAKE & al. 1991, QUANJER & al. 1993). There are often very significant variations in predicted values for Jung function indices. Such variation reflects, among other considerations (BECKLAKE & al. 1991, ZUSKIN & al. 1996), differences in the population studied, equipment used to measure Jung functions and methodology employed. As there are, at present, no references values for any adult Slovenian population, the results of spirometric testing have been mostly evaluated using reference values developed in other populations of Europe. Many studies have found that using reference values developed in other populations ofEurope and North America in practice are inadequate for some Jung function parameters(WITHERS & al. 1989a,b, SMOLEJ-NARANČIC & al. 1991, BRANDLI & al. 1996). The objectives of this investigation were, therefore, to define the correlations between spirometric values and measured anthropometric variables and to provide reliable standards in the form of prediction equations. Subjects and methods The study included 86 non-smoking female students, not participating in active sports. Only students without a history of respiratory illness or not showing its symptoms before or during the study and without chest wall deformity were included. We used a Standardized Medica! Research Council questionnaire (QUANJER & al. 1993) to screen the subjects on the basis of having : l. never suffered from asthma, chronic bronchitis, pneumonia, pulmonary tuberculosis, pleurisy 2. never had a persistent cough and/or phlegm for at least 3 months in a year 3. never had chest surgery and/or a major chest injury 4. never lived in a heavily polluted environment The students came from different parts of Slovenia, but the majority of them were from the city of Ljubljana. On average, they were 20.2 years old. Ali the measurements were performed in the autumn of 1996 between 8am and I pm, by the same technician. Spirometry Pulmonary function tests consisted of measuring forced expiratory vita! capacity (FEVC) and its subdivision, forced expiratory vol ume in the first second (FEV J The results were recorded according to recommendations of the European Respiratory Society (QUANJER & al. 1993). Tests were conducted at an altitude of 350m above mean sea leve), using a Spiro 323 spirometer (P.K. Morgan Instruments, Inc.). The spirometer was calibrated ona daily basis, using a precision syringe. Barometric pressure, water vapour pressure and ambient temperature were recorded daily. Recorded volumes were expressed as body temperature and pressure saturated with water vapour (BTPS). Ali the tests were performed with the subjects in a sitting possition and a nose-clip was used. Prior to their commencement, a careful demonstration of the tests was given to the subjects. FEVC measurements were repeated until three FEVC values were obtained that varied no more than 100 ml or 5%, and the highest values accepted. The data in Tab. 1 demonstrate a high degree of test retest reliability for ventilatory and anthropometric D. Zerbo-Šporin, M. Fležar, M . Štefančič: Ventylatory and anthropometric variables in healthy ... 33 variables. For predicting Jung volumes of the non-smoking adult woman, we used the equations recommended by the European Respiratory Society (QUANJER & al. 1993) that are commonly used in Slovenian medica! practice (see Tab. 4). They were derived from studies carried out on adult subjects (18-70 years) of European descent, who were non-smokers and without (previous) disease which could compromise their ventilatory function. Table J: Test-retest reliability statistic for Jung volumes and selected anthropometric variables Tabela J: Napaka meritve izmerjenih ventilacijskih parametrov in antropometričnih mer Variable Mean of the first Mean of the second Idi SEE measurements measurements FEVC(I) 4 .14 4.11 O.II 0.09 FEV1 (1) 3.58 3.59 0.07 0.06 Weight (kg) 60.6 60.8 0.21 0.37 Height (cm) 167.1 167.2 0.12 0.51 Sitting height (cm) 88.J 87.8 0.29 0.45 Arm span (cm) 165 .6 165.9 0.26 0.57 Shoulder width (cm) 37.2 37.2 0.03 0.38 Width of chest (cm) 26.1 26.1 0.02 0.45 Depth of chest (cm) 16.1 16.3 0.27 0.46 Chesl circumference at TLC (cm) 90.1 90.5 0.38 1.09 Chest circumference at FRC (cm) 84.5 84.6 O.II 1.27 Chest circumference at RV (cm) 87.0 86.6 0.42 1.20 Thickness of triceps skin-fold (mm) 14.2 13.9 0.37 0.62 Thickness of subscapular skin-fold (mm) 11.2 10.9 0.22 0.67 Thickness of midaxillary skin-fold (mm) 10.1 10.4 0.33 1.14 Thickness of suprailiac skin-fold (mm) 12.5 12.2 0.26 1.21 Thickness of medial calf skin-fold (mm) 16.I 15 .9 0.29 0.94 FRC: functional residual capacity RV: residual volume JdJ : mean of the absolute differences SEE: standard error of estimate r: the coefficient of reliability Anthropometry 0.97 0.98 0.99 0.98 0.97 0.99 0.93 0.94 0.90 0.93 0.94 0.94 0 .97 0.98 0.96 0.97 0.98 Anthropometric variables were measured according to the requirements of the Intemational Biol,,_ i- J Programme(WEINER & LOURIE l 969), using standard anthropometric equipment. Stature w .,s measured with an Siber-Hegner anthropometer to an accuracy of 0.1 cm. Body weight was measured on digital Soehnle scales to an accuracy of 0.1 kg. Skin-fold thicknesses were taken with a John Buli calliper, under a constant pressure of I O gmm·2• The same instruments were used throughout the study. Statistical analyses Ali the statistical analyses were performed using a pocket Statistica 4 .3 Statsoft program. After 1.:hecking: variables for normality and linearity of distribution, bivariate correlations between measured parameters were calculated. Forward stepwise multiple regression analyses were made to derive equations for predicting FEVC and FEV I values from the best weighted combination (with significance p