TY - JOUR
T1 - Alterations in growth and body composition during puberty
T2 - III. Influence of maturation, gender, body composition, fat distribution, aerobic fitness, and energy expenditure on nocturnal growth hormone release
AU - Roemmich, James N.
AU - Clark, Pamela A.
AU - Mai, Vu
AU - Berr, Stuart S.
AU - Weltman, Arthur
AU - Veldhuis, Johannes D.
AU - Rogol, Alan D.
PY - 1998
Y1 - 1998
N2 - We examined the relationships among gender, sexual maturation, four- compartment model estimates of body composition, body fat distribution (magnetic resonance imaging for abdominal visceral fat and anthropometrics), aerobic fitness, basal and total energy expenditure, and overnight GH release in an ultrasensitive chemiluminescence assay in healthy prepubertal and pubertal boys (n = 18 and 11, respectively) and girls (n = 12 and 18, respectively). Blood samples were withdrawn every 10 min from 1800-0600 h to determine the area under the serum GH-time curve (AUC), sum of the GH peak heights (Σ GH peak heights), and the mean nadir GH concentration. GH release was greater in the pubertal than prepubertal subjects due to an increase in Σ GH peak heights (43.8 ± 3.6 vs. 24.1 ± 3.5 ng · mL-1, P = 0.0002) and mean nadir (1.7 ± 0.2 vs. 0.7 ± 0.2 ng · mL-1, P = 0.0002), but not peak number (4.3 ± 0.2 vs. 4.5 ± 0.2). The girls had a greater Σ GH peak heights (39.0 ± 3.5 vs. 28.8 ± 3.6 ng · mL-1, P = 0.05) and mean nadir concentration (1.4 p 0.2 vs. 0.9 ± 0.2 ng · mL-1, P = 0.05) than the boys. Significant inverse relationships existed between Σ GH peak heights (r = -0.35, P = 0.06) or mean nadir (r = -0.39, P = 0.04) and four-compartment percent body fat for all boys but not for all girls or when combining all subjects. For all girls, significant inverse relationships existed between Σ GH peak heights (r = -0.39, P = 0.03) or mean nadir (r = -0.37, P = 0.04) and waist/hip ratio. Similar inverse relationships in all boys or all subjects were not significant. Forward stepwise regression analysis determined that bone age (i.e. maturation, primary factor) and gender were the significant predictors of AUC, Σ GH peak heights, and mean nadir. The influence of maturation reflects rising sex steroid concentrations, and the gender differences appear to be because of differences in estradiol concentrations rather than to body composition or body fat distribution.
AB - We examined the relationships among gender, sexual maturation, four- compartment model estimates of body composition, body fat distribution (magnetic resonance imaging for abdominal visceral fat and anthropometrics), aerobic fitness, basal and total energy expenditure, and overnight GH release in an ultrasensitive chemiluminescence assay in healthy prepubertal and pubertal boys (n = 18 and 11, respectively) and girls (n = 12 and 18, respectively). Blood samples were withdrawn every 10 min from 1800-0600 h to determine the area under the serum GH-time curve (AUC), sum of the GH peak heights (Σ GH peak heights), and the mean nadir GH concentration. GH release was greater in the pubertal than prepubertal subjects due to an increase in Σ GH peak heights (43.8 ± 3.6 vs. 24.1 ± 3.5 ng · mL-1, P = 0.0002) and mean nadir (1.7 ± 0.2 vs. 0.7 ± 0.2 ng · mL-1, P = 0.0002), but not peak number (4.3 ± 0.2 vs. 4.5 ± 0.2). The girls had a greater Σ GH peak heights (39.0 ± 3.5 vs. 28.8 ± 3.6 ng · mL-1, P = 0.05) and mean nadir concentration (1.4 p 0.2 vs. 0.9 ± 0.2 ng · mL-1, P = 0.05) than the boys. Significant inverse relationships existed between Σ GH peak heights (r = -0.35, P = 0.06) or mean nadir (r = -0.39, P = 0.04) and four-compartment percent body fat for all boys but not for all girls or when combining all subjects. For all girls, significant inverse relationships existed between Σ GH peak heights (r = -0.39, P = 0.03) or mean nadir (r = -0.37, P = 0.04) and waist/hip ratio. Similar inverse relationships in all boys or all subjects were not significant. Forward stepwise regression analysis determined that bone age (i.e. maturation, primary factor) and gender were the significant predictors of AUC, Σ GH peak heights, and mean nadir. The influence of maturation reflects rising sex steroid concentrations, and the gender differences appear to be because of differences in estradiol concentrations rather than to body composition or body fat distribution.
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U2 - 10.1210/jc.83.5.1440
DO - 10.1210/jc.83.5.1440
M3 - Article
C2 - 9589636
AN - SCOPUS:0031796413
SN - 0021-972X
VL - 83
SP - 1440
EP - 1447
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 5
ER -