Changes in resting energy expenditure and their relationship to insulin resistance and weight gain: a longitudinal study in pre-pubertal children (EarlyBird 17).
OBJECTIVE
In adults, adjustments in resting energy expenditure (REE) are used to defend energy balance against disturbance caused by over-and under-nutrition, and may be linked to changes in insulin resistance and leptin. Little is known of these associations in children. Our aim was to test the hypothesis that long-term weight gain in children is met with adaptive changes in resting energy expenditure, mediated by insulin resistance and/or leptin.


METHODS
REE by indirect calorimetry, anthropometry, body composition by DEXA, insulin resistance (HOMA-IR) and serum leptin were measured annually in 232 children from the age of 7-10 y.


RESULTS
REE rose from 7 to 10 y, and the rise exceeded that predicted by the concurrent rise in fat and fat-free mass by 184 kcal/day in the boys and by 160 kcal/day in the girls. However, there were no significant relationships in either gender between this 'excess' rise in REE and change in body composition (r < or = 0.08, p > or = 0.42). The rise in both boys and girls was associated with, but not explained by, a rise in insulin resistance (p < or = 0.002). There was no association with serum leptin (p > or = 0.32).


CONCLUSIONS
The data do not support the hypothesis of adaptive changes in REE in pre-pubertal children, and insulin resistance explains very little of the pre-pubertal rise in REE. The rise in REE beyond that explained by changes in body composition may reflect an increase in energy requirements prior to puberty.
Department of Endocrinology & Metabolism, Peninsula Medical School, Plymouth Campus, Plymouth, UK. joanne.hosking@phnt.swest.nhs.uk
Joanne
J
Hosking
William
W
Henley
Brad S
BS
Metcalf
Alison N
AN
Jeffery
Linda D
LD
Voss
Terence J
TJ
Wilkin
D015502:Absorptiometry, Photon; D000375:Aging; D000886:Anthropometry; D001481:Basal Metabolism; D001823:Body Composition; D002153:Calorimetry, Indirect; D002648:Child; D004734:Energy Metabolism; D005260:Female; D006706:Homeostasis; D006801:Humans; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D009751:Nutritional Requirements; D012727:Sex Characteristics; D015430:Weight Gain
D020738:Leptin