Effects of Adrenal and Gonadal HR in Young Women with AN

描述（由申请人提供）：严重骨质减少是神经性厌食症（AN）的常见且通常不可逆的并发症。患有AN的青少年通常具有降低的峰值骨量，并且早期骨质疏松症和骨折的风险增加。这些年轻女性血清性腺类固醇和肾上腺雄激素脱氢表雄酮（DHEA）水平低于正常，这可能与她们的低骨密度（BMD）有关。低DHEA水平伴随着胰岛素样生长因子I（IGF-I）、雌激素和睾酮水平的降低。本研究组先前的数据表明，口服DHEA治疗年轻女性AN：增加瘦体重，骨形成标志物和IGF-I的血清水平，并减少骨吸收的尿标志物。我们还发现，标准激素替代疗法（HRT）显着降低骨吸收标志物。这些治疗对骨强度和最终骨折风险的影响的信息缺乏。在这个项目中，我们将测试一个假设，即联合治疗脱氢表雄酮和雌激素/维生素B1通过合成代谢和抗溶骨性机制，将提高AN患者的骨量。我们将检验18个月的DHEA + HRT将增加这些患者的BMD和骨形成标志物，同时降低骨吸收标志物的假设。这项拟议中的研究将检查在这些年轻女性中恢复正常水平的DHEA和雌激素是否会在骨增生的关键时期增加骨量。该研究还将检查DHEA对骨骼的合成代谢作用是否通过骨骼IGF-I调节系统介导。使用双能X线吸收测定法（DXA）数据的横截面分析，我们还将测量骨结构几何学指数，以确定这些年轻女性的机械强度是否受损，以及强度是否在合成代谢/抗吸收联合治疗后恢复。为了获得新的信息，潜在的机制骨丢失和骨折风险的年轻女性与AN，我们的研究目标是：具体目标1：通过一项随机对照试验，以衡量18个月的过程中的DHEA + HRT对骨量的影响，骨转换的标志物，和血清IGF-I水平相比，安慰剂。具体目标二：通过DXA数据的横截面几何分析，确定与安慰剂相比，肾上腺和性腺类固醇替代联合治疗是否改变骨结构以增加强度。

DESCRIPTION (provided by applicant): Profound osteopenia is a frequent and often irreversible complication of anorexia nervosa (AN). Adolescents with AN often have a reduced peak bone mass and are at increased risk for early osteoporosis and fractures. These young women have subnormal serum levels of gonadal steroids and the adrenal androgen dehydroepiandrosterone (DHEA) that may be associated with their low bone mineral density (BMD). Low DHEA levels are accompanied by decreased levels of insulin-like growth factor I (IGF-I), estrogen, and testosterone. Previous data from our group indicate that oral DHEA therapy in young women with AN: increases lean body mass, serum levels of bone formation markers and IGF-I, and decreases urinary markers of bone resorption. We also found that standard hormonal replacement therapy (HRT) significantly decreased bone resorption markers. Information on the effects of these therapies on bone strength and ultimate fracture risk is lacking. In this project, we will test the hypothesis that combined therapy with DHEA and estrogen/progestin will enhance bone mass in patients with AN through anabolic and antiosteolytic mechanisms. We will test the hypothesis that 18 months of DHEA + HRT will increase BMD and markers of bone formation, while decreasing bone resorption markers in these patients. The proposed study will examine whether restoring normal levels of DHEA and estrogen in these young women will increase bone mass during a critical period for bone accretion. The study will also examine whether DHEA's anabolic effects on bone are mediated through the skeletal IGF-I regulatory system. Using cross-sectional analyses of dual energy x-ray absorptiometry (DXA) data, we will also measure indices of bone structural geometry to determine if mechanical strength is compromised in these young women, and if strength is restored in response to combined anabolic/antiresorptive therapy. To gain new information on the mechanisms underlying bone loss and fracture risk in young women with AN, our research goals are: Specific Aim 1: Through a randomized controlled trial, to measure the effects of an 18-month course of DHEA + HRT on bone mass, markers of bone turnover, and serum levels of IGF-I compared to placebo. Specific Aim 2: To determine whether combined therapy with adrenal and gonadal steroid replacement changes bone structure to increase strength compared to placebo, as assessed through cross-sectional geometric analysis of DXA data.