Pugeat M, Crave J C, Tourniaire J, Forest M G
Hospices Civils de Lyon, Laboratoire de la Clinique Endocrinologique, Hôpital de l'Antiquaille, France.
Horm Res. 1996;45(3-5):148-55. doi: 10.1159/000184778.
The high-affinity binding of the sex hormone-binding globulin (SHBG) for testosterone and to a lesser extent for estradiol influences the circulating levels of these sex steroid hormones, their biodisposal to target cells as well as their mutual balance. Although the regulation of SHBG is still not completely understood, in vitro studies performed with human hepatocarcinoma (Hep G2) cells have shown that estrogens and thyroxine stimulate SHBG secretion, by increasing the steady state of its mRNA concentrations. These observations are in good agreement with studies showing that SHBG levels increase during oral administration of estrogens as well as in patients with thyrotoxicosis. Interestingly, SHBG levels are normal in syndromes such as the abnormal transport of thyroid hormones and/or the syndrome of thyroid hormone resistance, which can be confused with thyrotoxicosis. By contrast, the effects of androgens are controversial. In many patients with hirsutism, SHBG concentrations are low and correlate negatively with both body mass index and fasting insulin levels. Because of the inhibitory effect of both insulin and insulin-like growth factor-1 on SHBG secretion by Hep G2 cells in vitro, it has been proposed that SHBG levels could be a marker of insulin resistance and/or hyperinsulinism in humans. Furthermore, an increased risk for either noninsulin-dependent diabetes and/or the overall mortality are associated with decreased SHBG levels in postmenopausal women. Finally, in men, SHBG levels are positively correlated with the concentration of high-density lipoprotein cholesterol. Therefore, the measurement of SHBG in clinical practice can be a useful diagnostic tool for: (1) correctly interpretating testosterone and estradiol serum concentrations; (2) investigating androgen-estrogen balance in gonadal and sexual dysfunctions; (3) assessing the peripheral effect of the hormones which regulate SHBG productions, and (4) evaluating insulin resistance and cardiovascular risk.
性激素结合球蛋白（SHBG）对睾酮具有高亲和力结合作用，对雌二醇的结合作用较弱，这会影响这些性甾体激素的循环水平、它们向靶细胞的生物处置以及它们之间的相互平衡。尽管对SHBG的调节仍未完全了解，但用人肝癌（Hep G2）细胞进行的体外研究表明，雌激素和甲状腺素通过增加其mRNA浓度的稳态来刺激SHBG分泌。这些观察结果与以下研究结果高度一致：口服雌激素期间以及甲状腺毒症患者中SHBG水平会升高。有趣的是，在诸如甲状腺激素异常转运和/或甲状腺激素抵抗综合征等可能与甲状腺毒症混淆的综合征中，SHBG水平是正常的。相比之下，雄激素的作用存在争议。在许多多毛症患者中，SHBG浓度较低，且与体重指数和空腹胰岛素水平均呈负相关。由于胰岛素和胰岛素样生长因子-1在体外对Hep G2细胞分泌SHBG具有抑制作用，因此有人提出SHBG水平可能是人类胰岛素抵抗和/或高胰岛素血症的标志物。此外，绝经后女性中SHBG水平降低与非胰岛素依赖型糖尿病和/或总体死亡率增加的风险相关。最后，在男性中，SHBG水平与高密度脂蛋白胆固醇浓度呈正相关。因此，在临床实践中测量SHBG可作为一种有用的诊断工具，用于：（1）正确解释睾酮和雌二醇的血清浓度；（2）研究性腺和性功能障碍中的雄激素-雌激素平衡；（3）评估调节SHBG产生的激素的外周作用；以及（4）评估胰岛素抵抗和心血管风险。
