Measurement of Zinc Absorption From Meals: Comparison of Extrinsic Zinc Labeling and Independent Measurements of Dietary Zinc Absorption
Measurement of Zinc Absorption From Meals: Comparison of Extrinsic Zinc Labeling and Independent Measurements of Dietary Zinc Absorption
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DOI：
10.1024/0300-9831.79.4.230
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发表时间：
2009-07-01
影响因子：
2.3
通讯作者：
Krebs, Nancy F.
中科院分区：
文献类型：
--
作者：
Sheng, Xiao-Yang;Hambidge, K. Michael;Krebs, Nancy F.
背景：外在标记技术通常用于测量锌的吸收分数（FAZ（外在）），但尚未得到充分评估。目的：比较使用 FAZ（外在）测量法测定吸收的锌量（TAZ（外在））与同时测定膳食锌吸收量（TAZ（代谢））的结果，后者不依赖于用外在示踪剂（改良的代谢平衡技术）标记摄入的食物。设计：连续 6 天，21 名健康、自由生活、饮食稳定的成年女性在三餐中口服 Zn-70。 Zn-68和Zn-67静脉内施用。使用双同位素示踪剂比率技术测量 FAZ（外在），并乘以膳食锌得到 TAZ（外在）。 TAZ（代谢）通过添加锌的净吸收和内源性粪便锌来测定，后者通过同位素稀释技术测定。结果：TAZ（外在）和 TAZ（代谢）分别为 3.0 +/- 1.1 毫克/天和 3.1 +/- 1.1 毫克/天，配对 t 检验 p = 0.492。 TAZ（外在）和TAZ（代谢）的相关系数为0.91，FAZ（外在）和FAZ（代谢）的相关系数为0.95。 Bland Altman 分析表明 TAZ（外在）和 TAZ（代谢）的偏差为 0.07，一致性限制为 -0.86 至 1.01。结论：两种独立方法的结果为我们的各种复合饮食的外在标签技术提供了合理的验证。
Background: Extrinsic labeling techniques are typically used to measure fractional absorption of zinc (FAZ(extrinsic)) but none have been adequately evaluated. Objective: To compare determination of the quantity of zinc absorbed (TAZ(extrinisic)) using measurements of FAZ(extrinsic) with results of simultaneous determinations of dietary zinc absorbed (TAZ(metabolic)) that are not dependent on labeling ingested food with an extrinsic tracer (modified metabolic balance technique). Design: Zn-70 was administered orally with all meals for 6 consecutive days to 21 healthy, free-living adult women consuming a constant diet. Zn-68 and Zn-67 were administered intravenously. FAZ(extrinsic) was measured using a dual isotope tracer ratio technique and multiplied by dietary zinc to give TAZ(extrinsic). TAZ(metabolic) was determined by addition of net absorption of zinc and endogenous fecal zinc, the latter determined by an isotope dilution technique. Results: and TAZ(extrinsic) and TAZ(metabolic) were 3.0 +/- 1.1 mg/day and 3.1 +/- 1.1 mg/day respectively, paired t-test p = 0.492. The correlation coefficient for TAZ(extrinsic) and TAZ(metabolic) was 0.91, and for FAZ(extrinsic) and FAZ(metabolic) was 0.95. A Bland Altman analysis indicated a bias of 0.07, and the limits of agreement of -0.86 to 1.01 for TAZ(extrinsic) and TAZ(metabolic). Conclusion: These results from two independent methods provide reasonable validation of our extrinsic labeling technique for a wide range of composite diets.