A simple single serum method to measure fractional calcium absorption using dual stable isotopes.
A simple single serum method to measure fractional calcium absorption using dual stable isotopes.
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一种使用双稳定同位素测量钙吸收分数的简单单血清方法。
DOI：
10.1055/s-0029-1234088
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Dawson-Hughes,B
中科院分区：
文献类型：
--
作者：
Ceglia,L;Abrams,SA;Harris,SS;Rasmussen,HM;Dallal,GE;Dawson-Hughes,B
双稳定同位素方法与定时24小时尿液收集是金标准的方法来衡量分数钙吸收。然而，需要收集24小时的尿液使得这项技术既耗时又费力。我们的研究试图确定是否使用一个单一的血清样本的初始同位素给药后4小时的双同位素方法提供了一个有用的方法来测量分数钙吸收。在固定钙摄入量为30 mmol/天的代谢性饮食持续10天后，19名54-74岁的健康受试者口服同位素（44 Ca），2小时后静脉注射同位素（42 Ca）。一旦给予口服同位素，收集尿液24小时，并在4小时后获得血清样品。通过质谱法测量尿液和血清中口服与静脉注射同位素的比例。4小时单一血清法测定的钙吸收分数为16.2±7.7%，24小时尿液法测定的钙吸收分数为18.5±7.5%。尿液和血清方法之间的平均差异较小，为2.33%，置信区间为-3.97至8.60%。两种方法显示出很强的线性相关性（r= 0.912，p< 0.001）。使用双稳定同位素与4小时单一血清法得到的钙吸收分数值比24小时尿液法低12.5%;然而，它对受试者进行了准确的排序，因此使其成为临床研究应用中有用的替代方法。
The dual stable isotope method with a timed 24-h urine collection is the gold standard approach to measure fractional calcium absorption. However, the need to collect urine for 24 h makes this technique time-consuming and laborious. Our study sought to determine whether a dual isotope method using a single serum sample obtained 4 h after administration of the initial isotope provides a useful approach to measure fractional calcium absorption. Following a metabolic diet with a fixed calcium intake of 30 mmol/day for 10 days, nineteen healthy subjects age 54–74 were given a test meal with an oral isotope (44 Ca) followed 2 h later by an intravenous isotope (42 Ca). Once the oral isotope was administered, urine was collected for 24 h, and a serum sample was obtained after 4 h. The ratio of the oral to intravenous isotopes was measured in the urine and serum by mass spectroscopy. Fractional calcium absorption was 16.2±7.7% by the 4-h single serum method versus 18.5±7.5% by the 24-h urine method. There was a small mean difference between the urine and serum methods of 2.33% with a confidence interval− 3.97 to 8.60%. The two methods showed a strong linear association (r= 0.912, p< 0.001). Use of dual stable isotopes with a 4-h single serum method gives fractional calcium absorption values that are 12.5% lower than with the 24-h urine method; however, it rank orders subjects accurately thus making it a useful alternative method in clinical research applications.
DOI：
10.1093/ajcn/70.6.955
发表时间：
1999-12
期刊：
The American journal of clinical nutrition
影响因子：
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作者：
S. Abrams
通讯作者：
S. Abrams
影响因子：
3.6
作者：
Griffin, IJ;Abrams, SA
通讯作者：
Abrams, SA
影响因子：
4.2
作者：
Heaney, RP
通讯作者：
Heaney, RP