Faculty of Exercise and Sport Sciences, University of Tartu, Jakobi 5, 51014 Tartu, Estonia.
J Bone Miner Metab. 2011 Nov;29(6):717-24. doi: 10.1007/s00774-011-0272-x. Epub 2011 May 21.
The aim of the present study was to investigate possible differences in plasma adipocytokine and ghrelin levels and body composition parameters in prepubertal rhythmic gymnasts (RG) and untrained controls (UC), and to examine the relationships of bone mineral density (BMD) with hormonal status in prepubertal children with different physical activity patterns. Eighty-nine 7- to 9-year-old girls participated in the study (RG, n = 46; UC, n = 43). Body composition and BMD were measured by dual-energy X-ray absorptiometry. Bone maturity was estimated by using a radiograph of the nondominant hand. The measured whole-body, lumbar spine (LS), and femoral neck (FN) BMD values were significantly higher (P < 0.05) in gymnasts than in controls. In addition, RG presented significantly lower and higher values (P < 0.05) for leptin and ghrelin concentrations, respectively, in comparison with UC. No differences were observed for adiponectin levels between the studied groups. No relationships between measured BMD values with leptin and ghrelin were observed even after adjustment for age and fat mass (FM) in RG. Whole-body and LS BMD values were significantly correlated with leptin after controlling for age and FM (r = 0.32, P < 0.05) in UC. Femoral neck BMD remained significantly correlated with ghrelin after adjusting for age and FM (r = -0.4, P < 0.05) in UC. No relationships were found between measured BMD values and adiponectin even after controlling for age and FM values in both groups. In conclusion, although all measured BMD values were significantly higher in RG, plasma adipocytokine and ghrelin concentrations were not directly related to bone mineralization in prepubertal RG in contrast to UC.
本研究旨在探讨青春期前艺术体操运动员（RG）和未训练对照组（UC）之间血浆脂肪细胞因子和 ghrelin 水平和身体成分参数的差异，并研究不同身体活动模式的青春期前儿童骨密度（BMD）与激素状态的关系。89 名 7-9 岁女孩参加了研究（RG，n=46；UC，n=43）。身体成分和 BMD 通过双能 X 射线吸收法测量。骨成熟度通过非优势手的 X 光片来估计。测量的全身、腰椎（LS）和股骨颈（FN）BMD 值在体操运动员中明显高于对照组（P<0.05）。此外，与 UC 相比，RG 中瘦素和 ghrelin 浓度分别表现出明显较低和较高的值（P<0.05）。两组之间的脂联素水平无差异。即使在 RG 中调整年龄和脂肪量（FM）后，也未观察到测量的 BMD 值与瘦素和 ghrelin 之间存在关系。在 UC 中，控制年龄和 FM 后，全身和 LS BMD 值与瘦素显著相关（r=0.32，P<0.05）。在 UC 中，控制年龄和 FM 后，股骨颈 BMD 仍与 ghrelin 显著相关（r=-0.4，P<0.05）。即使在两组中控制年龄和 FM 值后，也未发现测量的 BMD 值与脂联素之间存在关系。总之，尽管 RG 中所有测量的 BMD 值均显著升高，但与 UC 相比，青春期前 RG 中血浆脂肪细胞因子和 ghrelin 浓度与骨矿化无直接关系。
