Insulin-like growth factor-I in men with idiopathic osteoporosis
Insulin-like growth factor-I in men with idiopathic osteoporosis
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DOI：
10.1210/jc.82.9.2799
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发表时间：
1997-09-01
影响因子：
5.8
通讯作者：
Bilezikian, JP
中科院分区：
文献类型：
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作者：
Kurland, ES;Rosen, CJ;Bilezikian, JP
大多数没有酗酒、性腺功能减退或糖皮质激素过量史的男性骨质疏松症的病因尚不清楚。一些组织形态测量报告表明骨形成指数下降。我们测试了这样的假设：特发性骨质疏松症男性的骨形成减少可能与胰岛素样生长因子 I (IGF-I) 介导的骨骼机制缺陷有关。对 24 名患有严重特发性骨质疏松症（平均腰椎 T 评分 -3.5 +/- 0.16）的中年男性（50.5 +/- 1.9 岁）进行了研究。以下生化指标均正常：血清钙、25-羟基维生素D、1,25-二羟基维生素D、睾酮、骨钙素、I型胶原羧基端前肽、骨特异性碱性磷酸酶、尿钙和胶原交联。甲状旁腺激素水平处于正常范围下限，25 +/- 2 pg/mL (nl：10-65)。平均血清 IGF-I 水平也在正常范围的较低范围内，157.9 +/- 7.6 ng/mL（正常年龄匹配范围，140-260 ng/mL）。八名男性的 IGF-I 水平低于 140 ng/mL。平均 IGF-I Z 评分为 -0.75，与预期平均值 0 显着不同 (P = 0.0002)。 IGF-I 与年龄呈负相关（r = -0.49，P < 0.02）。在年龄保持不变的情况下，血清 IGF-I 占腰椎骨矿物质密度差异的 15%（BMD；P < 0.001）。骨钙素浓度与远端 1/3 半径处的骨密度密切相关 (r = + 0.44; P < 0.002)。骨活检标本的组织形态计量学分析显示松质骨体积 (31%; P < 0.001)、皮质宽度 (28%; P < 0.05)、类骨表面 (33%; P < 0.01) 和骨形成率显着减少（54%；P < 0.01）当结果与年龄匹配的对照受试者进行比较时。侵蚀表面百分比正常，与血清 IGF-I 水平呈负相关（r = -0.5；P < 0.04）。这些结果表明，患有特发性骨质疏松症的男性血清 IGF-I 水平降低，IGF-I 与腰椎骨密度 (BMD) 降低相关，并可能导致腰椎骨密度 (BMD) 降低。低 IGF-I 水平可能反映了组织形态计量学证明的骨形成减少。对 IGF-I 轴的进一步研究可能会揭示对男性特发性骨质疏松症病因学的见解。
The etiology of osteoporosis in most men without a history of alcohol abuse, hypogonadism, or glucocorticoid excess is unknown. Several histomorphometric reports have demonstrated a reduction in indices of bone formation. We tested the hypothesis that the putative reduction in bone formation in men with idiopathic osteoporosis may be related to deficiencies in skeletal mechanisms that are mediated by insulin-like growth factor I(IGF-I). Twenty-four middle-aged men (50.5 +/- 1.9 yr) with severe idiopathic osteoporosis (mean lumbar spine T-score -3.5 +/- 0.16) were studied. The following biochemical indices were all normal: serum calcium, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, testosterone, osteocalcin, carboxyterminal propeptide of type I collagen, bone specific alkaline phosphatase, urinary calcium, and collagen crosslinks. Parathyroid hormone level was in the lower range of normal, 25 +/- 2 pg/mL (nl: 10-65). Mean serum IGF-I level was also in the lower range of normal, 157.9 +/- 7.6 ng/mL (normal age-matched range, 140-260 ng/mL). Eight men had IGF-I levels that were below 140 ng/mL. The mean IGF-I Z score was -0.75, significantly different from the expected mean of zero (P = 0.0002). IGF-I was correlated negatively with age (r = -0.49, P < 0.02). With age held constant, serum IGF-I accounted for 15% of the variance in lumbar bone mineral density (BMD; P < 0.001). The osteocalcin concentration correlated well with bone density at the distal 1/3 radius (r = + 0.44; P < 0.002).Histomorphometric analysis of bone biopsy specimens showed significant reductions in cancellous bone volume (31%; P < 0.001), cortical width (28%; P < 0.05), osteoid surface (33%; P < 0.01), and bone formation rate (54%; P < 0.01) when results were compared with age-matched control subjects. Percent eroded surface was normal and was correlated inversely with serum IGF-I levels (r = -0.5; P < 0.04).These results suggest that serum IGF-I levels are reduced in men with idiopathic osteoporosis and that IGF-I correlates with and may contribute to the reduction in lumbar spine bone mass density (BMD). The low IGF-I levels may reflect the reduction in bone formation demonstrated by histomorphometry. Insights into the etiology of idiopathic osteoporosis in men may be revealed by further studies of the IGF-I axis.