Department of Pediatrics, Division of Pediatric Endocrinology, Cohen Children's Medical Center, New Hyde Park, NY 11040, USA.
J Bone Miner Res. 2012 Feb;27(2):283-93. doi: 10.1002/jbmr.550.
Nonclassic actions of vitamin D include potential regulation of immune function and glucose homeostasis. The bone-metabolism loop has recently been expanded to include osteocalcin, which appears to play a more direct role in pancreatic beta cell function and energy metabolism. We hypothesized that both vitamin D and osteocalcin would correlate negatively with indices of adiposity-related comorbidity risk in periadolescents, varying by ethnic group. We analyzed anthropometric, metabolic, and inflammatory markers from a multiethnic population of 106 school children 11 to 14 years of age studied as part of the Reduce Obesity and Diabetes (ROAD) consortium. As expected, 25-hydroxyvitamin D (25-OH vitamin D) was inversely correlated with intact parathyroid hormone (iPTH); total osteocalcin (OCN) and uncarboxylated osteocalcin (uOCN) were directly correlated with each other. OCN and uOCN concentrations correlated inversely with age. Vitamin D deficiency was most prevalent among East Asians (EA) and African Americans (AA). The highest lipid risk scores and homeostatic model for assessment of insulin resistance (HOMA-IR) values were seen in the South Asian (SA) group. Overall, adiposity measures were inversely correlated with OCN and iPTH, whereas such relationships were not observed for vitamin D. Acute insulin response to glucose challenge correlated negatively with uOCN in all subjects; however, lipid risk score correlated negatively with uOCN only in whites. The relationships between markers of calcium metabolism and body composition, glucose homeostasis, lipids, and inflammation all showed racial and ethnic differences. No consistent relationship was found between vitamin D and adiposity or vitamin D and glucose metabolism; instead vitamin D levels varied by race and ethnicity in this school-based group. These findings are consistent with the hypothesis that markers of calcium and bone metabolism may reflect risk for adiposity-related comorbidities in children.
维生素 D 的非经典作用包括对免疫功能和葡萄糖稳态的潜在调节。骨代谢循环最近已扩展到包括骨钙素，它似乎在胰岛β细胞功能和能量代谢中发挥更直接的作用。我们假设，维生素 D 和骨钙素与青少年肥胖相关合并症风险的指标呈负相关，且这种相关性因种族而异。我们分析了作为减少肥胖和糖尿病（ROAD）联盟研究的一部分的、由来自多民族的 106 名 11 至 14 岁的学龄儿童组成的人群的人体测量、代谢和炎症标志物。正如预期的那样，25-羟维生素 D（25-OH 维生素 D）与完整甲状旁腺激素（iPTH）呈负相关；总骨钙素（OCN）和非羧化骨钙素（uOCN）相互之间呈正相关。OCN 和 uOCN 浓度与年龄呈反比。维生素 D 缺乏在东亚人（EA）和非裔美国人（AA）中最为普遍。南亚人（SA）组的血脂风险评分和胰岛素抵抗评估的稳态模型（HOMA-IR）值最高。总的来说，肥胖指标与 OCN 和 iPTH 呈负相关，而与维生素 D 则没有观察到这种关系。所有受试者的葡萄糖刺激后急性胰岛素反应与 uOCN 呈负相关；然而，只有在白人中，血脂风险评分与 uOCN 呈负相关。钙代谢和身体成分、葡萄糖稳态、脂质和炎症的标志物之间的关系均表现出种族和民族差异。在这个基于学校的群体中，没有发现维生素 D 与肥胖或维生素 D 与葡萄糖代谢之间的一致关系；相反，维生素 D 水平因种族和民族而异。这些发现与这样的假设一致，即钙和骨代谢标志物可能反映儿童肥胖相关合并症的风险。
