Division of Endocrinology and Metabolism, S. Croce & Carle Hospital, Cuneo, Italy.
Calcif Tissue Int. 2011 Mar;88(3):231-7. doi: 10.1007/s00223-010-9453-1. Epub 2011 Jan 5.
Osteocalcin (OC) has been proposed as a regulator of insulin sensitivity in both humans and other animals. Primary hyperparathyroidism (PHPT) is characterized by high OC levels and insulin resistance. The aim of this study was to evaluate whether in PHPT the link between OC levels and blood markers of insulin resistance was maintained. In a consecutive series of 219 adult PHPT patients, serum OC as well as fasting insulin and glucose levels were measured. Insulin sensitivity was estimated by homeostatic model assessment (HOMA2-S%). The same parameters were evaluated in a subgroup of 45 patients after parathyroidectomy (PTX). PHPT patients were characterized by markedly high OC levels. After subdividing them according to glucose tolerance, it was found that OC was similar in subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT), while diabetic subjects had lower serum OC than those with NGT (P < 0.02) or IGT (P < 0.04). OC was negatively associated with fasting glucose and positively associated with HOMA2-S%. OC independently predicted HOMA2-S% in a multivariate analysis. In the subgroup of surgically cured PHPT patients, OC levels significantly decreased after PTX, while HOMA2-S% did not change. Our findings indicate that in PHPT there is a positive relationship between OC and glucose metabolism, OC being one of the predictors of insulin sensitivity. However, data in surgically cured patients, showing OC normalization in spite of unchanged HOMA2-S%, suggest that OC does not likely play a major role in affecting insulin sensitivity in PHPT.
骨钙素（OC）被认为是人类和其他动物胰岛素敏感性的调节剂。原发性甲状旁腺功能亢进症（PHPT）的特征是 OC 水平升高和胰岛素抵抗。本研究旨在评估 PHPT 中 OC 水平与血液胰岛素抵抗标志物之间的联系是否保持不变。在连续的 219 例成年 PHPT 患者中，测量了血清 OC 以及空腹胰岛素和血糖水平。用稳态模型评估（HOMA2-S%）估计胰岛素敏感性。在 45 例甲状旁腺切除术（PTX）后的患者亚组中评估了相同的参数。PHPT 患者的 OC 水平明显升高。根据葡萄糖耐量将其细分后发现，OC 在糖耐量正常（NGT）和糖耐量受损（IGT）的受试者中相似，而糖尿病患者的血清 OC 低于 NGT（P < 0.02）或 IGT（P < 0.04）。OC 与空腹血糖呈负相关，与 HOMA2-S%呈正相关。OC 在多变量分析中独立预测 HOMA2-S%。在手术治愈的 PHPT 患者亚组中，PTX 后 OC 水平显著降低，而 HOMA2-S%没有变化。我们的研究结果表明，在 PHPT 中，OC 与葡萄糖代谢之间存在正相关关系，OC 是胰岛素敏感性的预测因子之一。然而，在手术治愈的患者中，OC 正常化而 HOMA2-S%不变的数据表明，OC 不太可能在 PHPT 中对胰岛素敏感性产生重大影响。
