Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Department of Endocrinology, Jiangmen Central Hospital, Affiliated Jiangmen Hospital of Sun Yat-sen University, Jiangmen, Guangdong, China.
PLoS One. 2021 Dec 2;16(12):e0260521. doi: 10.1371/journal.pone.0260521. eCollection 2021.
This study analysed the associations of sex steroids with fat-free mass (FFM) and handgrip strength in 641 Chinese boys. Serum total testosterone (TT) and oestradiol were measured by chemiluminescence immunoassay. Free testosterone (FT) and oestradiol were calculated. FFM and handgrip strength were measured by bioelectrical impedance analysis and a hand dynamometer, respectively. Generalised additive models and multiple linear regression were used to explore the relationships. A subgroup analysis was conducted in early-mid pubertal and late-post pubertal groups. Age, height, weight, physical activity, intake of dietary protein and/or stage of puberty were adjusted. TT and FT were positively related to FFM and handgrip strength, with a curvilinear relationship being detected for handgrip strength (p<0.050). This curvilinear relationship was only observed in the late-post pubertal group, suggesting a potential threshold effect (FT>11.99ng/dL, β = 1.275, p = 0.039). In the early-mid pubertal group, TT and/or FT were linearly or near-linearly related to FFM or handgrip strength (β = 0.003-0.271, p<0.050). The association between FT and FFM was stronger than that in the late-post pubertal group. This study found that serum T had different associations with muscle parameters in Chinese early-mid pubertal and late-post pubertal boys. In the late-post pubertal boys, serum T was curvilinearly related to muscle strength with a threshold effect and its link with muscle mass was weaker.
本研究分析了 641 名中国男孩的性激素与去脂体重（FFM）和握力之间的关系。采用化学发光免疫分析法检测血清总睾酮（TT）和雌二醇。计算游离睾酮（FT）和雌二醇。FFM 和握力分别采用生物电阻抗分析法和手持测力计进行测量。采用广义加性模型和多元线性回归来探讨这些关系。在青春期早期-中期和青春期后期晚期进行了亚组分析。调整了年龄、身高、体重、体力活动、膳食蛋白质摄入量和/或青春期阶段。TT 和 FT 与 FFM 和握力呈正相关，握力呈曲线关系（p<0.050）。这种曲线关系仅在青春期后期晚期观察到，表明存在潜在的阈值效应（FT>11.99ng/dL，β=1.275，p=0.039）。在青春期早期-中期，TT 和/或 FT 与 FFM 或握力呈线性或近线性相关（β=0.003-0.271，p<0.050）。FT 与 FFM 的关联比青春期后期晚期更强。本研究发现，血清 T 与中国青春期早期-中期和青春期后期晚期男孩的肌肉参数有不同的关联。在青春期后期晚期男孩中，血清 T 与肌肉力量呈曲线关系，存在阈值效应，与肌肉质量的关联较弱。
