Mechanism of circadian variation in bone resorption
Mechanism of circadian variation in bone resorption
复制标题
DOI：
10.1016/s8756-3282(01)00662-7
复制
发表时间：
2002-01-01
期刊：
影响因子：
4.1
通讯作者：
Christiansen, C
中科院分区：
文献类型：
--
作者：
Bjarnason, NH;Henriksen, EEG;Christiansen, C
骨吸收标志物的昼夜变化知之甚少，可能包含有关骨吸收调节的重要信息。为了探讨骨吸收的急性调节，我们研究了14名绝经后妇女在一项随机，交叉，24 - 11研究口服葡萄糖耐量试验（OGTT），正常饮食，或禁食的骨转换。尽管禁食抵消了骨吸收的变化，如通过血清I型胶原降解的C-端肽片段（s-CTx）测量的，但OGTT和正常饮食在2小时内诱导了50%的减少（p < 0.001）。对于OGTT，s-CTx在6小时后恢复到基线水平，对于正常饮食，s-CTx在下午保持抑制，并在夜间恢复到基线水平。9名绝经后妇女在上午8：00和下午8：00进行重复OGTT，结果表明，两个时间点的s-CTx降低程度相同，两次试验之间恢复至基线水平的程度居中。在23名男性和绝经前女性中进行的一项2小时OGTT和禁食随机交叉研究同样显示s-CTx下降了50%。在6名男性和绝经前女性中进行的胰岛素耐量试验与空腹相比的随机、交叉2小时研究表明，s-CTx降低20%-30%（p < 0.01-0.05）。在OGTT、蛋白质和脂肪摄入量的交叉实验期间，对10名健康个体进行9小时随访，结果显示s-CTx降低了50%，但血清葡萄糖和血清胰岛素谱不同。食物、葡萄糖、脂肪和蛋白质的摄入减少了骨吸收，禁食则抵消了骨吸收，这似乎与年龄和性别无关。外源性和内源性胰岛素刺激试验均诱导骨吸收减少，但与摄食期间观察到的减少相比，这只是部分减少。(C)2002年，Elsevier Science Inc. All rights reserved.
The diurnal variation in bone resorption markers is poorly understood and may contain essential information about regulation of bone resorption. To explore the acute regulation of bone resorption we studied bone turnover in 14 postmenopausal women during a randomized, crossover, 24 11 study of oral glucose tolerance test (OGTT), normal diet, or fasting. Whereas fasting counteracted variation in bone resorption, as measured by serum C-telopeptide fragments of collagen type I degradation (s-CTx), OGTT and normal diet induced a 50% reduction (p < 0.001) over 2 h. For OGTT, s-CTx reverted to baseline levels after 6 h, and for normal diet s-CTx remained suppressed during the afternoon and returned to baseline overnight. Repeated OGTT at 8:00 A.M. and 8:00 P.M. in nine postmenopausal women demonstrated that identical reductions in s-CTx could be obtained at both timepoints with an intermediate return to baseline between tests. A 2 h randomized, crossover study of OGTT and fasting in 23 men and premenopausal women similarly revealed a 50% decrease in s-CTx. A randomized, crossover 2 h study of insulin tolerance test compared with fasting in six men and premenopausal women demonstrated a 20%-30% decrease in s-CTx (p < 0.01-0.05). Nine hour follow-up of ten healthy individuals during a crossover experiment of OGTT, protein, and fat intake revealed a comparable 50% reduction in s-CTx, but distinct profiles of serum glucose and serum insulin. Bone resorption was reduced by intake of food, glucose, fat, and protein and counteracted by fasting, and this seems to have been be independent of age and gender. Both exogenous and endogenous insulin stimulation tests induced a reduction in bone resorption, but this was only partial when compared with the reduction observed during food intake. (C) 2002 by Elsevier Science Inc. All rights reserved.