Purpose: To examine the effect of growth hormone (GH) treatment on physical performance in children with idiopathic short stature and normal GH secretion. Materials and Methods : A total of 24 children participated in the study (13 GH-treated, 11 non-treated, aged 8–13 y, 11 males and 13 females, Tanner stage 1–2). Participants performed a battery of motor skill performance tests (Eurofit), as well as the Wingate anaerobic test. Results: No statistically significant differences in any of the Eurofit physical fitness test results (eg, 20-m shuttle run 33.0 [15.1] vs 25.1 [21.0] laps in treated and nontreated participants, respectively, P = .25) or the Wingate anaerobic test were found between the groups (eg, peak power 5.0 [2.9] vs 3.9 [2.6] watts/kg in treated and nontreated participants, respectively, P = .2). Conclusions: Therapeutic usage of exogenous GH for pre and early pubertal children with idiopathic short stature and normal GH secretion was not associated with beneficial effects on physical performance indices. This suggests that the use of GH as a potential performance enhancing agent, in this age group, at least at commonly used doses, is not advantageous.
Adi Weinberg, Nitzan Dror, Katya Motin, Michal Pantanowitz, Dan Nemet, and Alon Eliakim
Sigal Ben-Zaken, Yoav Meckel, Nitzan Dror, Dan Nemet, and Alon Eliakim
In recent years several genetic polymorphisms related to the GH-IGF-I axis were suggested to promote athletic excellence in endurance and power sports. We studied the presence of the C-1245T SNP (rs35767), a nucleotide substitution in the promoter region of the IGF-I gene, and the presence of the 275124A > C SNP (rs1464430), a common nucleotide substitution in the intron region of the IGF-I receptor (IGF-IR) gene in elite long and short-distance swimmers compared with nonphysically active controls. The rare T/T IGF-I polymorphism was found only in 5.3% of the long-distance swimmers, and was not found at all in the short-distance swimmers or among the control group participants. The prevalence of the IGF-I receptor AA genotype was significantly lower in the swimming group as a whole (35%) compared with the control group (46%), in particularly due to reduced frequency of the AA genotype among short-distance swimmers (26%). In contrast to previous reports in elite endurance and power track and field athletes, single nucleotide polymorphisms of the IGF-I and the IGF-IR were not frequent among elite Israeli short- and long-distance swimmers emphasizing the importance of other factors for excellence in swimming. The results also suggest that despite seemingly similar metabolic characteristics different sports disciplines may have different genetic polymorphisms. Thus, combining different disciplines for sports genetic research purposes should be done with extreme caution.
Alon Eliakim, Bareket Falk, Neil Armstrong, Fátima Baptista, David G. Behm, Nitzan Dror, Avery D. Faigenbaum, Kathleen F. Janz, Jaak Jürimäe, Amanda L. McGowan, Dan Nemet, Paolo T. Pianosi, Matthew B. Pontifex, Shlomit Radom-Aizik, Thomas Rowland, and Alex V. Rowlands
This commentary highlights 23 noteworthy publications from 2018, selected by leading scientists in pediatric exercise science. These publications have been deemed as significant or exciting in the field as they (a) reveal a new mechanism, (b) highlight a new measurement tool, (c) discuss a new concept or interpretation/application of an existing concept, or (d) describe a new therapeutic approach or clinical tool in youth. In some cases, findings in adults are highlighted, as they may have important implications in youth. The selected publications span the field of pediatric exercise science, specifically focusing on: aerobic exercise and training; neuromuscular physiology, exercise, and training; endocrinology and exercise; resistance training; physical activity and bone strength; growth, maturation, and exercise; physical activity and cognition; childhood obesity, physical activity, and exercise; pulmonary physiology or diseases, exercise, and training; immunology and exercise; cardiovascular physiology and disease; and physical activity, inactivity, and health.