Center for Endocrinology, Diabetes, and Metabolism at Children's Hospital Los Angeles, Keck School of Medicine of USC, Los Angeles, CA, USA.
Clin Endocrinol (Oxf). 2012 Feb;76(2):228-35. doi: 10.1111/j.1365-2265.2011.04187.x.
C-type natriuretic peptide (CNP) and thyroid hormone (TH) are essential for normal skeletal growth. Plasma CNP peptides correlate with growth velocity, but the relationship between thyroid status and CNP production is unknown. This study examined the impact of restoring normal TH levels on CNP and height velocity (HV) in children with acquired hypo- and hyperthyroidism.
We performed a prospective, observational study in prepubertal children with acquired hypothyroidism (n = 15) and hyperthyroidism (n = 12).
Blood levels of CNP, amino-terminal proCNP (NTproCNP), bone-specific alkaline phosphatase (BSAP), IGF-I and TH levels were measured before and during the first 6 months of standard treatment for hypo- and hyperthyroidism, and correlations were determined.
At baseline, HV, CNP, NTproCNP and BSAP were significantly higher in hyper- than in hypothyroid subjects. Changes in TH after treatment were closely coupled to change in CNP and NTproCNP in hyperthyroid, but not in hypothyroid, children. In addition, a positive association of HV with CNP peptides was found during treatment of hyperthyroidism. Normalizing TH did not correlate with changes in BSAP or IGF-I in either group.
Plasma CNP peptides are higher in children with hyperthyroidism than in those with hypothyroidism at diagnosis and, in hyperthyroid children, change concordantly with TH and HV during treatment. Differential responses of CNP in the two groups suggest CNP production is dependent on growth plate activity and not a direct effect of TH on CNP gene expression. Our findings suggest novel mechanisms underlying changes in skeletal response during treatment in children with acquired thyroid disease.
C 型利钠肽（CNP）和甲状腺激素（TH）是骨骼正常生长所必需的。血浆 CNP 肽与生长速度相关，但甲状腺状态与 CNP 产生之间的关系尚不清楚。本研究旨在探讨恢复正常 TH 水平对获得性甲状腺功能减退症和甲状腺功能亢进症儿童 CNP 和身高速度（HV）的影响。
我们对 15 例获得性甲状腺功能减退症和 12 例甲状腺功能亢进症的青春期前儿童进行了前瞻性、观察性研究。
在接受标准治疗的前 6 个月内，测量了 CNP、氨基末端 proCNP（NTproCNP）、骨特异性碱性磷酸酶（BSAP）、IGF-I 和 TH 水平，并确定了相关性。
在基线时，HV、CNP、NTproCNP 和 BSAP 在甲状腺功能亢进症患者中明显高于甲状腺功能减退症患者。治疗后 TH 的变化与甲状腺功能亢进症儿童而非甲状腺功能减退症儿童的 CNP 和 NTproCNP 变化密切相关。此外，在治疗甲状腺功能亢进症期间发现 HV 与 CNP 肽呈正相关。在两组中，TH 正常化均与 BSAP 或 IGF-I 的变化无关。
在诊断时，甲状腺功能亢进症儿童的血浆 CNP 肽高于甲状腺功能减退症儿童，并且在甲状腺功能亢进症儿童中，在治疗期间与 TH 和 HV 变化一致。两组中 CNP 的不同反应表明 CNP 的产生取决于生长板的活性，而不是 TH 对 CNP 基因表达的直接影响。我们的研究结果表明，获得性甲状腺疾病儿童在治疗期间骨骼反应变化的新机制。
