Relative contributions of testosterone and estrogen in regulating bone resorption and formation in normal elderly men
Relative contributions of testosterone and estrogen in regulating bone resorption and formation in normal elderly men
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DOI：
10.1172/jci10942
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发表时间：
2000-12-01
影响因子：
15.9
通讯作者：
Khosla, S
中科院分区：
文献类型：
--
作者：
Falahati-Nini, A;Riggs, BL;Khosla, S
不能产生雌激素（E）或对其无反应的年轻成年男性患有骨质减少症，这表明雌激素可能像在女性中一样，也对男性的骨转换起调节作用。具有生物活性的雌激素和睾酮（T）在老年男性中都会大幅下降，但不清楚哪种激素缺乏是导致骨吸收增加和骨形成受损进而引起骨质流失的更重要因素。因此，我们通过抑制59名老年男性（平均年龄68岁）体内内源性睾酮和雌激素的产生来直接解决这一问题。首先在生理性睾酮和雌激素替代的条件下对他们进行研究，然后评估同时停用睾酮和雌激素、仅停用睾酮、仅停用雌激素或继续使用两种激素对骨转换的影响。在两种激素都缺乏的情况下，骨吸收标志物显著增加，而在两种激素都使用的男性中则没有变化。通过双因素方差分析，雌激素在防止骨吸收标志物增加方面起主要作用，而睾酮没有显著影响。相比之下，血清骨钙素（一种骨形成标志物）在两种激素都缺乏时下降，并且雌激素和睾酮都能维持骨钙素水平。我们得出结论，在老年男性中，雌激素是调节骨吸收的主要性类固醇，而雌激素和睾酮在维持骨形成方面都很重要。
Young adult males who cannot produce or respond to estrogen (E) are osteopenic, suggesting that E may regulate bone turnover in men, as well as in women. Both bioavailable E and testosterone (T) decrease substantially ill aging men, but it is unclear which deficiency is the more important factor contributing to the increased bone resorption and impaired bone formation that leads to their bone loss. Thus, of addressed this issue directly by eliminating endogenous T and E production in 59 elderly men (mean age 68 years), studying them first under conditions of physiologic T and E replacement and then assessing the impact on bone turnover of withdrawing both T and E, withdrawing only T, or only E, or continuing both. Bone resorption markers increased significantly in the absence of both hormones and were unchanged in men receiving both hormones. By two-factor ANOVA, E played the major role in preventing the increase in the bone resorption markers, whereas T had no significant effect. By contrast, serum osteocalcin, a bone formation marker, decreased in the absence of both hormones, and both E and T maintained osteocalcin levels. We conclude that in aging men, E is the dominant sex steroid regulating bone resorption, whereas both E and T are important in maintaining bone formation.