USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030, USA.
Division of Pediatric Endocrinology and Diabetes, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030, USA.
J Clin Endocrinol Metab. 2022 Aug 18;107(9):e3797-e3804. doi: 10.1210/clinem/dgac344.
Childhood obesity disproportionately affects Hispanic youth. The skeletal system appears to be a target organ of the adverse effects of obesity. Yet, the relationship between adiposity and bone health in youth and the modulating factors are not well understood.
This work aims to examine the relationship between adiposity, insulin resistance (IR), cardiorespiratory fitness (CRF), and bone mass in Hispanic youth.
A total of 951 Hispanic youth (50% male), aged 4 to 19 years, participated in this cross-sectional design study from the Viva La Familia Study at Children's Nutrition Research Center. Bone mineral content (BMC) and density (BMD), lean mass (LM), total body fat mass (FM), truncal FM were obtained using dual-energy x-ray absorptiometry. Fasting glucose and insulin were obtained and the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. CRF was measured using a treadmill ramp protocol. We applied linear regression models and mediation analyses.
Adiposity measures were negatively related to BMC and BMD after accounting for LM and sex. IR negatively contributed whereas CRF positively contributed to the variance in BMC and BMD, more notably in the pubertal age group. In mediation analysis, HOMA-IR partially mediated the negative relationship of adiposity to BMC (standardized indirect effect [IE] = -0.0382; 95% CI, -0.0515 to -0.0264) whereas the sequential IE of HOMA-IR and CRF partially attenuated (IE = -0.0026; 95% CI, -0.0053 to -0.0005) this relationship. Similar findings were seen with BMD as the primary outcome.
IR mediates the negative relationship between adiposity and bone mass whereas CRF may partially attenuate it.
儿童肥胖症在西班牙裔青少年中不成比例地高发。骨骼系统似乎是肥胖不良影响的靶器官。然而，肥胖症与青少年骨健康之间的关系及其调节因素尚不清楚。
本研究旨在探讨西班牙裔青少年体脂率、胰岛素抵抗（IR）、心肺适能（CRF）与骨量之间的关系。
共有 951 名西班牙裔青少年（50%为男性）参与了这项横断面设计研究，年龄在 4 至 19 岁之间，他们来自儿童营养研究中心的“Viva La Familia”研究。采用双能 X 射线吸收法测定骨矿物质含量（BMC）和密度（BMD）、瘦体重（LM）、全身脂肪量（FM）和躯干 FM。空腹血糖和胰岛素被检测，通过计算稳态模型评估的胰岛素抵抗（HOMA-IR）得出胰岛素抵抗情况。采用跑步机斜坡方案测量心肺适能。我们应用线性回归模型和中介分析。
在考虑 LM 和性别后，体脂率与 BMC 和 BMD 呈负相关。IR 对 BMC 和 BMD 的变异有负贡献，而 CRF 对 BMC 和 BMD 的变异有正贡献，在青春期年龄组更为明显。在中介分析中，HOMA-IR 部分介导了体脂率与 BMC 之间的负相关关系（标准化间接效应[IE]=-0.0382；95%CI，-0.0515 至-0.0264），而 HOMA-IR 和 CRF 的顺序 IE 部分减弱了这种关系（IE=-0.0026；95%CI，-0.0053 至-0.0005）。作为主要结果的 BMD 也出现了类似的发现。
IR 介导了体脂率与骨量之间的负相关关系，而 CRF 可能部分减弱了这种关系。
