Body composition and the expiratory reserve volume of pre-pubertal lean and obese boys and girls.
Previously, we examined the expiratory reserve volume (ERV) of the lungs as a function of percentage body fat in an adult population (age range 18-58 years). A negative correlation resulted when ERV (expressed as a percentage of vital capacity, (ERV/VC) x 100) was regressed on percentage fat for both sexes. In the present study, similar comparisons were made for 33 pre-pubertal boys and girls (aged 7-12.5 years). The regression equation for the boys ((ERV/VC) x 100 = 44.2 - 0.56%fat, r = -0.77, P = 0.002) was similar to that of the adult men ((ERV/VC) x 100 = 48.7 - 0.80 %fat, r = -78) and women ((ERV/VC) x 100 = 49.5 - 0.63 %fat, r = -0.70). However, the girls studied did not follow the same pattern. In this group of pre-pubertal girls, a significant increase in (ERV/VC) x 100 with increasing body fatness was seen ((ERV/VC) x 100 = 29.3 + 0.19 %fat, r = 0.48, P = 0.03). In all four groups, no correlation was seen with age or height. Whereas there was a significant correlation between weight and (ERV/VC) x 100 in the adults, no such relationship was evident in the younger subjects. In pre-pubertal obese girls limited upper body muscle development, perhaps as a result of limited physical activity, may explain the different relationship between ERV and body fatness.
Barlett
H L
HL
Laboratory for Human Performance Research, Pennsylvania State University, University Park 16802.
Kenney
W L
WL
Buskirk
E R
ER
D001823:Body Composition; D001835:Body Weight; D002648:Child; D005105:Expiratory Reserve Volume; D005260:Female; D006801:Humans; D008297:Male; D009132:Muscles / Q000502:physiology; D009765:Obesity / Q000503:physiopathology*; D012044:Regression Analysis