有神经管缺陷妊娠史女性的叶酸吸收情况。

Folate absorption in women with a history of neural tube defect-affected pregnancy.

作者信息

Boddie A M, Dedlow E R, Nackashi J A, Opalko F J, Kauwell G P, Gregory J F, Bailey L B

机构信息

Department of Food Science and Human Nutrition, College of Agriculture, University of Florida, Gainesville, FL 32611, USA.

出版信息

Am J Clin Nutr. 2000 Jul;72(1):154-8. doi: 10.1093/ajcn/72.1.154.

DOI:10.1093/ajcn/72.1.154

PMID:10871574

Abstract

BACKGROUND

The risk of neural tube defects (NTDs) is significantly reduced by supplemental folic acid. NTD risk may be associated with impaired absorption of polyglutamyl folate, the primary form of naturally occurring food folate, and of folic acid in supplements or fortified food. Stable-isotope methods provide the specificity needed to test this hypothesis.

OBJECTIVE

We determined whether women who had an NTD-affected pregnancy had a reduced ability compared with control women to absorb polyglutamyl folate relative to folic acid.

DESIGN

Healthy, nonpregnant women with a history of an NTD-affected pregnancy (cases; n = 11) and control women (n = 11) were administered an oral dose containing a mixture of [(2)H]pteroylpentaglutamate ([(2)H(2)]PteGlu(5); 233 nmol) and [(13)C]pteroylmonoglutamate ([(13)C(5)]PteGlu(1); 567 nmol) after a 30-d saturation protocol (2 mg unlabeled folic acid/d). Relative extents of absorption were evaluated by urinary excretion of (2)H(2)- and (13)C(5)-labeled folates 48 h postdose.

RESULTS

During the first 24 h postdose, cases excreted less (f1.gif" BORDER="0"> +/- SD) [(2)H(2)]PteGlu(5) (21 +/- 12% compared with 37 +/- 19%; P = 0.01) and [(13)C(5)]PteGlu(1) (17 +/- 8% compared with 31 +/- 14%; P = 0.007) than did controls. No significant differences between cases and controls were detected in the percentage of [(2)H(2)]PteGlu(5) or [(13)C(5)]PteGlu(1) excreted during the second 24 h postdose or when the data were averaged over 48 h. However, excretion of the [(2)H(2)]folates tended to be lower in cases than in controls over the 48-h period (33 +/- 13% compared with 45 +/- 26%; P = 0.21). A similar trend (P = 0.29) for lower excretion of [(13)C(5)]folates in cases was also observed (31 +/- 16% compared with 39 +/- 17%). The ratio of urinary [(2)H(2)]folates to [(13)C(5)]folates did not differ significantly between cases and controls.

CONCLUSION

These data suggest the need for a larger-scale study using stable-isotope methods to further investigate this hypothesis.

摘要

背景

补充叶酸可显著降低神经管缺陷（NTDs）的风险。NTD风险可能与多聚谷氨酸叶酸（天然食物叶酸的主要形式）以及补充剂或强化食品中的叶酸吸收受损有关。稳定同位素方法提供了检验这一假设所需的特异性。

目的

我们确定与对照女性相比，曾有过NTD相关妊娠的女性吸收多聚谷氨酸叶酸相对于叶酸的能力是否降低。

设计

对有NTD相关妊娠史的健康非妊娠女性（病例组；n = 11）和对照女性（n = 11），在经过30天的饱和方案（每天2毫克未标记叶酸）后，口服给予含有[(2)H]蝶酰五谷氨酸（[(2)H(2)]PteGlu(5)；233纳摩尔）和[(13)C]蝶酰单谷氨酸（[(13)C(5)]PteGlu(1)；567纳摩尔）的混合物。给药后48小时，通过(2)H(2)-和(13)C(5)-标记叶酸的尿排泄量评估相对吸收程度。

结果

给药后的前24小时内，病例组排泄的[(2)H(2)]PteGlu(5)（分别为21 ± 12%和37 ± 19%；P = 0.01）和[(13)C(5)]PteGlu(1)（分别为17 ± 8%和31 ± 14%；P = 0.007）比对照组少。在给药后第二个24小时或48小时数据平均时，病例组和对照组排泄的[(2)H(2)]PteGlu(5)或[(13)C(5)]PteGlu(1)百分比无显著差异。然而，在48小时期间，病例组[(2)H(2)]叶酸的排泄量往往低于对照组（分别为33 ± 13%和45 ± 2 = 0.21）。病例组[(13)C(5)]叶酸排泄量较低也有类似趋势（分别为31 ± 16%和39 ± 17%；P = 0.29）。病例组和对照组尿中[(2)H(2)]叶酸与[(13)C(5)]叶酸的比值无显著差异。