Searchable abstracts of presentations at key conferences in endocrinology
Endocrine Abstracts (2014) 35 P820 | DOI: 10.1530/endoabs.35.P820

1Endocrine Unit, Second Department of Obstetrics and Gynecology, Aretaieion Hospital, Athens University Medical School, Athens, Greece; 2First Department of Pediatrics, ‘Aghia Sofia’ Children’s Hospital, Athens University Medical School, Athens, Greece; 3School of Physical Education and Sports Sciences, Democritus University of Thrace, Komotini, Greece; 4Endocrine Unit, Evgenidion Hospital, Athens University, Athens, Greece; 5Pediatric Endocrinology Unit, Third Department of Pediatrics, Hippokrateion Children’s Hospital, Aristotle University Medical School, Thessaloniki, Greece.


Oxidative stress in humans has been associated with obesity. Puberty is a maturation period characterized mainly by changes of the GH and the gonadotrophin hormones secretion. To investigate the possible association of the GH and the hypothalamic–pituitary–gonadal (HPG) axes before and during early puberty, with the pro- and anti-oxidation mechanisms 76 healthy, pre-pubertal normal weight (n=28), pre-pubertal obese (n=11), early pubertal normal weight (n=25) and early pubertal obese (n=12) male pupils of the 5th and 6th grades of an elementary school were studied at baseline and after a sub-maximal exercise protocol (on a stationary cycle ergometer) at 70% VO2max. All subjects underwent blood sampling before and after this exercise bout for measurement of pro- (thiobarbituric acid reactive substances (TBARS) and protein carbonyls (PCs) and anti- (glutathione (GSH) and the oxidized glutathione disulfide (GSSG), the GSH:GSSG ratio, the enzymes glutathione peroxidase (GPX) and catalase and total antioxidant capacity (TAC)) oxidation markers and hormones (GH, IGF1, IGFBP3, FSH, LH, and testosterone).

Baseline and post-exercise TBARS and PCs were significantly greater while baseline GSH, GSH:GSSG, and TAC were significantly lower in obese than in normal weight subjects. Baseline and post-exercise GPX was significantly lower in obese than normal weight pre-pubertal subjects. GH and testosterone concentrations were lower in early pubertal obese compared to normal weight subjects. Early pubertal subjects demonstrated greater amounts of TAC than pre-pubertal ones at baseline. Following the exercise bout, TBARS, PCs, GSSG, TAC, catalase, and GPX increased while GSH and the ratio GSH:GSSG decreased in all studied groups. GH concentrations increased following exercise in early pubertal subjects. Multiple regression analysis of all subjects, revealed statistically significant positive linear regression between the exercise-associated GH increase and that of GSSG. In all studied subjects baseline GH was the best negative predictor for post-exercise PCs. Baseline waist circumference was the best negative and positive predictor for post-exercise concentrations of GPX and for TBARS respectively.

In conclusion, moderate acute aerobic exercise is a good model for the study of the pro- and anti-oxidation mechanisms. Obese subjects demonstrate greater pro- and lower anti-oxidation mechanisms than normal-weight subjects while also demonstrating lower GH concentrations in early puberty. These observations highlight the deleterious potential of obesity. The anti-oxidant capacity of the organism seems to improve with puberty along with the potentiation of the exercise-associated GH increase.

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