Zikan Vit, Stepan Jan J
Department of Internal Medicine 3, Charles University, Faculty of Medicine, Prague, Czech Republic.
Bone. 2009 Apr;44(4):634-8. doi: 10.1016/j.bone.2008.12.013. Epub 2008 Dec 24.
The aim of this study was to assess the effects of the antiresorptive treatments of alendronate (ALN), risedronate (RIS) and raloxifene (RLX) on the response of bone to endogenous parathyroid hormone (PTH) induced by acute hypocalcemia. Forty women (age, 55-80 years) with postmenopausal osteoporosis (treated with ALN, RIS and RLX or untreated-control group) were given infusions of sodium ethylenediaminetetraacetic acid (EDTA; 10 mg/kg of body weight). Serum ionized calcium (iCa), plasma intact PTH and marker of bone resorption, serum beta C-terminal telopeptide of type I collagen (beta-CTX; beta CrossLaps) were followed for 180 min. In all women, decrease in serum iCa following the EDTA load resulted in an acute increase in serum PTH. Between 60 and 180 min, plasma PTH in the ALN and RIS treated women remained significantly higher than in the control group. The integrated beta-CTX responses (area under curves, AUCs) to peaks of PTH were significantly lower in the ALN treated women than in those treated with RIS, RLX or control group. There was no significant difference in beta-CTX AUC response to PTH between RIS, RLX and control women. Taken together, these findings suggest that in women with postmenopausal osteoporosis treated with ALN, a substantial reduction of bone turnover blunts the acute bone resorbing effect of endogenous PTH.
本研究旨在评估阿仑膦酸盐（ALN）、利塞膦酸盐（RIS）和雷洛昔芬（RLX）等抗吸收治疗对急性低钙血症诱导的内源性甲状旁腺激素（PTH）作用下骨反应的影响。40名年龄在55 - 80岁之间的绝经后骨质疏松症女性（分为接受ALN、RIS和RLX治疗组或未治疗的对照组）静脉输注乙二胺四乙酸钠（EDTA；10mg/kg体重）。监测血清离子钙（iCa）、血浆完整PTH以及骨吸收标志物血清I型胶原β-羧基末端肽（β-CTX；β交联C末端肽）180分钟。所有女性在EDTA负荷后血清iCa降低，导致血清PTH急性升高。在60至180分钟之间，接受ALN和RIS治疗的女性血浆PTH显著高于对照组。ALN治疗组女性对PTH峰值的β-CTX综合反应（曲线下面积，AUCs）显著低于接受RIS、RLX治疗的女性或对照组。RIS、RLX治疗组女性与对照组女性之间，β-CTX对PTH的AUC反应无显著差异。综上所述，这些发现表明，在接受ALN治疗的绝经后骨质疏松症女性中，骨转换的大幅降低减弱了内源性PTH的急性骨吸收作用。
