Amin Shreyasee, Riggs B Lawrence, Melton L Joseph, Achenbach Sara J, Atkinson Elizabeth J, Khosla Sundeep
Division of Rheumatology, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
J Bone Miner Res. 2007 Jun;22(6):799-807. doi: 10.1359/jbmr.070306.
Elevated serum IGFBP-2 is associated with lower BMD in men and women. It is unknown whether IGFBP-2 serves as a negative regulator of bone metabolism by decreasing bone formation or increasing bone resorption. Studying an age-stratified community-based sample of 344 men and 276 women, IGFBP-2 was the strongest predictor of increased bone resorption among the IGF/IGFBPs studied.
Serum insulin-like growth factor binding protein-2 (IGFBP-2), which increases with age, is a predictor of low BMD among aging men and women. However, it is unknown whether IGFBP-2 negatively influences bone metabolism by decreasing bone formation or increasing bone resorption. Few have examined the relation between the insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) with bone turnover markers.
In an age-stratified, random sample of the community, we examined the association between serum IGF-I, IGF-II, IGFBP-1, -2, and -3, and bone turnover markers before and after adjustment for potential confounders (age, body mass index, bioavailable estradiol and testosterone, and sex hormone binding globulin). Analyses were stratified by sex and menopausal status.
We studied 344 men (age range, 23-90 yr) and 276 women (age range, 21-93 yr; 166 postmenopausal) not on oral contraceptives or hormone replacement. Among the IGF/IGFBPs assessed, IGFBP-2 was the strongest and most consistent predictor of bone turnover in men and women. After adjustment for potential confounders, IGFBP-2 was positively associated with osteocalcin (OC) and urine and serum N-teleopeptide (NTX) in men (r = 0.20, 0.26, and 0.23, respectively; p < 0.001), serum C-telopeptide (CTX) in premenopausal women (r = 0.28; p < 0.01), and OC, urine NTX, and serum CTX in postmenopausal women (r = 0.24, 0.33, and 0.19, respectively; p < 0.05).
Higher serum IGFBP-2, which is predictive of lower BMD, is associated with increased markers of bone resorption, independent of age, body mass, and sex hormones. The association between IGFBP-2 and markers of bone formation may reflect coupling with increased bone resorption, which is not adequate to maintain BMD.
血清IGFBP - 2升高与男性和女性较低的骨密度相关。目前尚不清楚IGFBP - 2是否通过减少骨形成或增加骨吸收来作为骨代谢的负调节因子。在一项基于社区的344名男性和276名女性的年龄分层样本研究中，IGFBP - 2是所研究的IGF/IGFBPs中骨吸收增加的最强预测因子。
血清胰岛素样生长因子结合蛋白 - 2（IGFBP - 2）随年龄增加，是老年男性和女性低骨密度的预测因子。然而，尚不清楚IGFBP - 2是否通过减少骨形成或增加骨吸收对骨代谢产生负面影响。很少有人研究胰岛素样生长因子（IGFs）及其结合蛋白（IGFBPs）与骨转换标志物之间的关系。
在一个年龄分层的社区随机样本中，我们在调整潜在混杂因素（年龄、体重指数、生物可利用雌二醇和睾酮以及性激素结合球蛋白）之前和之后，研究了血清IGF - I、IGF - II、IGFBP - 1、 - 2和 - 3与骨转换标志物之间的关联。分析按性别和绝经状态分层。
我们研究了344名男性（年龄范围23 - 90岁）和276名女性（年龄范围21 - 93岁；166名绝经后），这些人未服用口服避孕药或激素替代药物。在所评估的IGF/IGFBPs中，IGFBP - 2是男性和女性骨转换最强且最一致的预测因子。在调整潜在混杂因素后，IGFBP - 2与男性的骨钙素（OC）、尿和血清N - 端肽（NTX）呈正相关（分别为r = 0.20、0.26和0.23；p < 0.001），与绝经前女性的血清C - 端肽（CTX）呈正相关（r = 0.28；p < 0.01），与绝经后女性的OC、尿NTX和血清CTX呈正相关（分别为r = 0.24、0.33和0.19；p < 0.05）。
较高的血清IGFBP - 2可预测较低的骨密度，且与骨吸收标志物增加相关，独立于年龄、体重和性激素。IGFBP - 2与骨形成标志物之间的关联可能反映了与增加的骨吸收的耦合，而这种耦合不足以维持骨密度。
