Comparison Of Lung Function In Urban And Rural Greek Children Using Allometric Scaling

Introduction
There is a dearth of studies focusing in lung function differences between urban and rural Greek children. Furthermore,
most of the studies that have investigated lung function have made comparisons with either matched controls or
predicted values. In our knowledge only one study has used an allometric scaling technique in Greece [1]. Therefore,
the aim of this study was to compare urban and rural Greek primary schoolchildren on measures of lung function using
allometric scaling.

Methods
189 urban and 171 rural boys and 125 urban and 122 rural girls, all age 11-12 yrs at the time of testing, performed
forced expiratory manoeuvres into a portable spirometer. Measurements included forced vital capacity (FVC), forced
expiratory volume in one second (FEV1), and peak expiratory flow (PEF). Body mass and stature were also measured
using standardised anthropometric techniques. ln stature was the most related anthropometric variable to all log
transformed lung function variables (r= .566, .661, and 465 respectively, P<0.001). Therefore, each lung function
variable (y) was corrected for the stature (x), using power function ratios (y·x -b) [2]. To evaluate differences in
corrected lung function data in urban and rural subjects, an unpaired t-test was used for each gender.

Results
The initial regression analyses to determine commonality of slopes produced non-significant (p>0.05) interaction terms
for all relationships. In table 1 are presented the derived exponents for b with 95% confidence interval (CI) and the
explained variance (R2). Urban children had superior PEF while no significant difference was found in FVC and FEV1
(Table 2).

Discussion / Conclusions
Although there was significant difference only in PEF, urban children tended to be better than rural children regarding
the FVC and FEV1. Considering that there was not a significant difference in total physical activity between urban and
rural Greek children (Tsimeas, unpublished data) and that lung function comparisons in this study were performed
corrected for stature, is recommended to future researchers to explore other environmental factors affecting PEF.

References
[1]. Doherty M. & Dimitriou L. (1997). British Journal of Sports Medicine, 31,337-341
[2]. Winter E. (1992). Pediatric Exercise Science, 4, 296-301.

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