Study On Pulmonary Functions And The Related Factors Among Pupils In Hefei

Aim: To investigate the normal reference values of pulmonary functions and explore the related influential factors by measuring the lung functions among the 6-12 year-old primary school health students in a primary school in Hefei.Method: Sample of these health students was taken by randomization. Among them, there were 38 boys and 32 girls who were assigned to groups by every age, and each group consisted of 10 students. Routine ventilation lung functions were performed on the pulmonary function instrument: MASTER SCREEN PAED which was made by the Germany JAEGER Company. At first, anthropologic references such as height, weight, sitting height, length of arm, circumference of arm, chest and head were measured; then number of family members, exposure of passive smoking, history of delivery and BCG immunization were investigated through questionnaires. Standard procedures according to the guideline were operated by trained doctors. At the next step, skin prickle tests were done to check out some allergic agents, such as weeds, moulds, chinar, birches, house dust mites, big nettle, powder dust mites, animal furs, feathers and lobsters, all of these testing substances were made in Germany. The sterilized needle for only one-time utilization was prickled lightly under the skin of the font bent side of the right arms at the same depth and to avoid bleeding while performing, phosphorus histamine was used as the positive comparative reaction while the physiological salt solution was used as the negative comparative one. PPD (Purified Protein Derivative,PPD) test was done intracutaneous as well with syringe to take in 0.1 ml PPD having 5 units tuberculin to shoot on the convergence spot of middle and down 1/3 of the left arm so that skin mound of 6-10 mm in diameter could be formed, the so called Mantoux test. The reactive results were arranged to be observed after 48-72 hours. Diameters of the local hard nodes were measured with soft rulers, the reaction intensity was judged on both the horizontal and vertical average diameters. SPSS 10.0 was used to perform the statistic analysis. T test was used to compare the mean values between 2 groups, while values for the comparison among many groups and comparison between every 2 values were tested by use of univariate Analysis of Variance: ANOVA. Association between variables was analyzed by use of multivariate linear regression. Comparison between the measured values and predicated values of lung functions was analyzed by the adoption of randomized section and group ANOVA. In the analysis of multivariate linear regression, the statistic significance for the differenceαwas 0.10 or 0.05. The measured values of the pulmonary function were defined as the dependent variables while the independent variables consisted of age, weight, height, sitting height, length of arm, circumference of arm, chest and head; number of the often residing family members, exposure to passive smoking, allergic tests and PPD reaction; cesarean delivery, normal delivery or preterm delivery.Results :It was shown that the average weight was 37.87±10.19 (kg), the average height was 139.41±11.11 (cm), mean of sitting height was 72.56±6.26 (cm), length of arm: 44.48±3.77 (cm), circumference of head: 52.48±1.36 (cm), circumference of arm: 22.75±2.88 (cm) and the mean of circumference of chest was 68.60±7.25 (cm).Overalls to see that the actually measured values of lung functions increased with the increasing of the age, among them, FVC, FEV1, PEF, FEV1%, FVC, MV, MVV, FEF25, FEF50 have shown more obvious increase while VT, IC, ERV, VC MAX had limited increase until one was 10 years old. In addition, there was statistically significant difference between the actually measured values and the predicated values for VT, MV, FEV1%, FVC, MVV, FEF25, FEF75 (P<0.05) while there was no significant difference for FVC, FEV1, FEF50, VCMAX, IC, ERV (P>0.05). Still more, it was shown that the regression coefficient between height and all the measured pulmonary function:β>0, and P<0.05 or P<0.10, so was the regression coefficient between sitting height and IC, ERV, VC MAX, MV, FVC, FEV1, MVV, PEF, PEF25:β>0, and P<0.05 or P<0.10. The regression coefficient between length of arm and VT, IC, VC MAX, FVC, FEV1, MVV, PEF, PEF25:β>0, and P<0.05 or P<0.10, positive correlation was displayed while the regression coefficient between circumference of arm and FVC:β<0, P<0.10, negative correlation and there was no statistic significance between circumference of arm and other values of lung function P>0.05 or P>0.10, no relationship. As to the regression coefficient between the circumference of chest and IC, VC MAX, FVC:β>0, and P<0.05, positive correlation while the regression coefficient between the circumference of chest and VT,MV:β<0, P<0.10, negative correlation was displayed. Moreover, the regression coefficient between the circumference of head and VT, MV:β>0, and P<0.05 or P<0.10, positive correlation was displayed. The regression coefficient between weight and all the measured pulmonary indicators showed no significant difference, P>0.05 or P>0.10, no relationship was present. Interesting was that the regression coefficient between the living areas and VT, MV, FEV1, MVV, PEF, ERV, FEF75, FEF50, FEV1%, FVC:β>0, and P<0.05 or P≤0.10, there was positive correlation. So was the regression coefficient between number of the often residing family members and FEF50, FEV1%, FVC. Skin prickle tests showed that the regression coefficient between positive allergic reaction and all the indicators of lung function:β<0, P<0.05 or P<0.10, negative correlation existed while for the PPD test, the regression coefficient between positive PPD test and FEV1%, FVC:β<0, and P<0.10, there was negative correlation and between positive PPD test and FEF25: P>0.10, no correlation showed. However, the regression coefficient between positive PPD test and all the rest indicators of lung function:β>0 and P<0.05 or P≤0.10, there was positive correlation. It seemed that there was no correlation between all the indicators of the lung function and passive smoking exposure, cesarean delivery, normal delivery and preterm newborns because of no statistic significance: P>0.10. The most frequent allergic agent was powder dust mites, and all the others was house dust mites, lobster, moulds, feathers, animal furs, birch, weeds, nettle, chinar and treeⅠby frequency in turn. Percentage of positive PPD test was 30%.Conclusions:Through this investigation, we got both the physical growth indicators: weight, height, sitting height, length, circumference of chest, arm and head, and the routine pulmonary function indicators in healthy students between 6-12 years old in the local areas, by the way, we found out the positive percentage of allergic response and PPD test. At the last step, we performed the analysis of the correlation between all the above factors and pulmonary function. Results showed that age and height were most related to lung function, positive correlation was displayed, next to height were sitting height, length of arm and circumference of chest related to lung function, and weight, circumference of arm and circumference of head were least related to lung function. In addition, there was positive relation between living areas, positive PPD tests and lung function while negative relation showed between positive allergic reaction and lung function. In the end, there was no relationship between passive smoking exposures, cesarean delivery, normal delivery, preterm born and the pulmonary function for school aged children.