Tomlinson OW, Barker AR, Oades PJ, Williams CA
Med Sci Sports Exerc. 2017 Oct;49(10):1980-1986.
PURPOSE: The aim of this study was to describe the relationship between body size
and oxygen uptake efficiency slope (OUES) in pediatric patients with cystic
fibrosis (CF) and healthy controls (CON), to identify appropriate scaling
procedures to adjust the influence of body size upon OUES.
METHODS: The OUES was derived using maximal and submaximal points from
cardiopulmonary exercise testing in 72 children (36 CF and 36 CON). OUES was
subsequently scaled for stature, body mass (BM), and body surface area (BSA)
using ratio-standard (Y/X) and allometric (Y/X) methods. Pearson’s correlation
coefficients were used to determine the relationship between body size and OUES.
RESULTS: When scaled using the ratio-standard method, OUES had a significant
positive relationship with stature (r = 0.54, P < 0.001) and BSA (r = 0.25, P =
0.031) and significant negative relationship with BM (r = -0.38, P = 0.016) in
the CF group. Combined allometric exponents (b) for CF and CON were stature 3.00,
BM 0.86, and BSA 1.40. A significant negative correlation was found between OUES
and stature in the CF group when scaled allometrically (r = -0.37, P = 0.027).
Nonsignificant (P > 0.05) correlations for the whole group were found between
OUES and allometrically scaled BM (CF r = -0.25, CON, r = 0.15) and BSA (CF r =
-0.27, CON r = 0.13).
CONCLUSIONS: Only allometric scaling of either BM or BSA, and not ratio-standard
scaling, successfully eliminates the influence of body size upon OUES. Therefore,
this enables a more direct comparison of the OUES between patients with CF and