Gorai I, Taguchi Y, Chaki O, Nakayama M, Minaguchi H
Department of Obstetrics and Gynecology, Yokohama City University School of Medicine 3-9 Fukuura, Kanazawa-ku, Yokohama 236, Japan.
Calcif Tissue Int. 1997 Apr;60(4):317-22. doi: 10.1007/s002239900235.
Urinary excretion of cross-linked N-telopeptide of type I collagen (NTx) has been reported to be a specific marker of bone resorption [18]. We assessed a new immunoassay for NTx as an indicator of changes in bone resorption caused by spontaneous menopause and compared cross-sectionally the levels of urinary NTx, hydroxylysylpyridinoline (HP), lysylpyridinoline (LP), hydroxyproline (OH-Pr), other serum biochemical indices, and lumbar spine and proximal femur bone mineral density (BMD). Eighty-one Japanese women aged 22-77 participated in this study; 36 were premenopausal and 45 were postmenopausal. Urinary HP, LP, and NTx stayed at low levels in the premenopausal period and rose 21%, 30%, and 67% in the postmenopausal period, respectively. The rise in LP and NTx was statistically significant (P < 0.01), suggesting that NTx is mostly released from bone matrix when bone resorption is accelerated. When premenopausal women were divided into two age groups and postmenopausal women were divided into two groups according to years since menopause (YSM) there were significant differences in LP and NTx between women <4 YSM and women aged <40 and those women aged 41+ (P < 0.01 and P < 0.05, respectively). A significant 110% increase in urinary NTx and a 48% increase in urinary LP were observed in postmenopausal women compared with age-matched premenopausal women aged 45-55. All biochemical markers other than serum PTH correlated significantly with each other (r = 0. 243-0.858, P < 0.05-0.0001). Urinary NTx inversely correlated with lumbar spine BMD. When postmenopausal women were divided into three groups, the correlation between bone resorption and formation markers in women 0-1 YSM was greater than in women 2-10 YSM and in women 11 + YSM, indicating that resorption and formation are coupled at the early postmenopausal period. We conclude that urinary NTx is responsive to changes in bone metabolism caused by estrogen deficiency and may be a more sensitive and specific marker than HP, LP, or OH-Pr in the early postmenopausal years.
I型胶原交联N-端肽（NTx）的尿排泄已被报道为骨吸收的特异性标志物[18]。我们评估了一种新的NTx免疫测定法，作为自发性绝经引起的骨吸收变化的指标，并对尿NTx、羟赖氨酰吡啶啉（HP）、赖氨酰吡啶啉（LP）、羟脯氨酸（OH-Pr）、其他血清生化指标以及腰椎和股骨近端骨密度（BMD）水平进行了横断面比较。81名年龄在22 - 77岁的日本女性参与了本研究；36名处于绝经前，45名处于绝经后。尿HP、LP和NTx在绝经前期维持在低水平，并在绝经后期分别上升了21%、30%和67%。LP和NTx的上升具有统计学意义（P < 0.01），表明当骨吸收加速时，NTx主要从骨基质中释放出来。当将绝经前女性分为两个年龄组，将绝经后女性根据绝经年限（YSM）分为两组时，YSM < 4年的女性与年龄 < 40岁的女性以及41岁及以上女性之间的LP和NTx存在显著差异（分别为P < 0.01和P < 0.05）。与年龄匹配（45 - 55岁）的绝经前女性相比，绝经后女性的尿NTx显著增加110%，尿LP增加48%。除血清甲状旁腺激素外，所有生化标志物之间均存在显著相关性（r = 0.243 - 0.858，P < 0.05 - 0.0001）。尿NTx与腰椎BMD呈负相关。当将绝经后女性分为三组时，YSM为0 - 1年的女性中骨吸收与形成标志物之间的相关性大于YSM为2 - 10年的女性以及YSM为11年及以上的女性，这表明在绝经后早期骨吸收与形成是耦合的。我们得出结论，尿NTx对雌激素缺乏引起的骨代谢变化有反应，并且在绝经后早期可能是比HP、LP或OH-Pr更敏感和特异的标志物。
