Cavaliere H, Knobel M, Medeiros-Neto G
Horm Res. 1987;25(3):132-9. doi: 10.1159/000180644.
The effect of thyroid hormone therapy (L-T4 or L-T3) on plasma immunoreactive insulin-like growth factor I (somatomedin C, Sm-C) concentrations was studied in 8 normal controls, 14 primary hypothyroid subjects and in 7 patients with endemic cretinism. In normals basal levels of Sm-C (1.56 +/- 0.77 U/ml) increased to (2.46 +/- 1.0 U/ml; L-T4) and to (2.9 +/- 0.95 U/ml; L-T3). Plasma Sm-C basal levels were significantly lower in primary hypothyroid subjects (0.81 +/- 0.48 U/ml) and increased to 2.54 +/- 1.43 U/ml (L-T4) and to 2.16 +/- 0.83 U/ml (L-T3). A significant and positive correlation (r = 0.56) was found between Sm-C and serum T4 and T3 concentrations. Plasma Sm-C concentrations in endemic cretinism were initially normal in 4 patients, but low in the remaining 3 (mean +/- SD: 1.18 +/- 0.63 U/ml) and did not increase after 12 months (1.34 +/- 0.61 U/ml) or 18 months (1.01 +/- 0.43 U/ml) of L-T4 and L-T3 therapy. Plasma T4 levels and free T4 increased considerably in EC after therapy with a significant decrease in the previously elevated plasma TSH concentrations. The subnormal response of plasma Sm-C during effective thyroid thyroid hormone therapy could be an additional factor involved in growth failure of endemic cretins.
在8名正常对照者、14名原发性甲状腺功能减退患者和7名地方性克汀病患者中，研究了甲状腺激素疗法（左甲状腺素或左三碘甲状腺原氨酸）对血浆免疫反应性胰岛素样生长因子I（生长介素C，Sm-C）浓度的影响。在正常人群中，Sm-C的基础水平（1.56±0.77 U/ml）分别升至（2.46±1.0 U/ml；左甲状腺素）和（2.9±0.9 U/ml；左三碘甲状腺原氨酸）。原发性甲状腺功能减退患者的血浆Sm-C基础水平显著较低（0.81±0.48 U/ml），分别升至2.54±1.43 U/ml（左甲状腺素）和2.16±0.83 U/ml（左三碘甲状腺原氨酸）。发现Sm-C与血清T4和T3浓度之间存在显著正相关（r = 0.56）。4名地方性克汀病患者的血浆Sm-C浓度最初正常，但其余3名患者较低（平均±标准差：1.18±0.63 U/ml），在接受左甲状腺素和左三碘甲状腺原氨酸治疗12个月（1.34±0.61 U/ml）或18个月（1.01±0.43 U/ml）后未升高。治疗后，地方性克汀病患者的血浆T4水平和游离T4显著升高，之前升高的血浆促甲状腺激素浓度显著降低。在有效的甲状腺激素治疗期间，血浆Sm-C反应异常可能是地方性克汀病生长发育迟缓的另一个相关因素。
