母乳中的硒代胱氨酸作为中国不同地理缺硒风险地区哺乳期妇女硒摄入量的生物标志物。

Breast milk selenocystine as a biomarker for selenium intake in lactating women at differential geographical deficiency risk in China.

作者信息

He Meng-Jie, Zhang Shuang-Qing, Liu Liping, Han Feng, Chai Yingjuan, Zhang Jie, Wang Shijin, Wang Qin, Liu Yiqun, Sun Licui, Lu Jiaxi, Yang Qiu, Huang Linghe, Huang Zhen-Wu

机构信息

National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China.

Zhejiang Center for Disease Control and Prevention, Hangzhou, China.

出版信息

Asia Pac J Clin Nutr. 2019;28(2):341-346. doi: 10.6133/apjcn.201906_28(2).0016.

DOI:10.6133/apjcn.201906_28(2).0016

PMID:31192563

Abstract

BACKGROUND AND OBJECTIVES

A reliable biomarker for optimal selenium (Se) intake in lactating women is not currently available.

METHODS AND STUDY DESIGN

Daily dietary Se intake in lactating women was calculated from a 24-hour meal record survey for over 3 days. Se levels in plasma and breast milk were measured through inductively coupled plasma mass spectrometry. Plasma selenoprotein P 1 levels and glutathione peroxidase 3 activity were measured using an enzyme-linked immunosorbent assay. Ultra-performance liquid chromatography-tandem mass spectrometry was used to analyze proteinaceous Se species in enzymatically digested breast milk.

RESULTS

Dietary Se intakes of lactating women from Liangshan, Beijing, and Enshi were 41.6±21.2 ng/d, 51.1±22.6 ng/d, and 615±178 ng/d, respectively (p<0.05). The Se levels in the blood and breast milk were significantly associated with the dietary Se intake (p<0.05). The proteinaceous Se species in breast milk were SeMet and SeCys2. The levels of SeMet in the lactating women from Liangshan, Beijing, and Enshi were 3.31±2.44 ng Se/mL, 7.34±3.70 ng Se/mL, and 8.99±9.64 ng Se/mL, while that of SeCys2 were 13.7±12.0 ng Se/mL, 35.6±20.9 ng Se/mL, and 57.4±13.2 ng Se/mL, respectively. Notably, the concentration of SeCys2, the metabolite of unstable SeCys, reached a saturation platform, whereas no similar phenomenon were found for the total Se SeMet from Secontaining proteins.

CONCLUSIONS

SeCys2 in breast milk is a potential biomarker for determining the optimal Se intake in lactating women.

摘要

背景与目的

目前尚无可靠的生物标志物用于确定哺乳期妇女的最佳硒（Se）摄入量。

方法与研究设计

通过连续3天以上的24小时膳食记录调查计算哺乳期妇女的每日膳食硒摄入量。采用电感耦合等离子体质谱法测定血浆和母乳中的硒水平。使用酶联免疫吸附测定法测量血浆硒蛋白P1水平和谷胱甘肽过氧化物酶3活性。采用超高效液相色谱-串联质谱法分析酶解母乳中的蛋白质硒种类。

结果

凉山、北京和恩施哺乳期妇女的膳食硒摄入量分别为41.6±21.2 ng/d、51.1±22.6 ng/d和615±178 ng/d（p<0.05）。血液和母乳中的硒水平与膳食硒摄入量显著相关（p<0.05）。母乳中的蛋白质硒种类为硒代蛋氨酸（SeMet）和硒代半胱氨酸（SeCys2）。凉山、北京和恩施哺乳期妇女的SeMet水平分别为3.31±2.44 ng Se/mL、7.34±3.70 ng Se/mL和8.99±9.64 ng Se/mL，而SeCys2的水平分别为13.7±12.0 ng Se/mL、35.6±20.9 ng Se/mL和57.4±13.2 ng Se/mL。值得注意的是，不稳定硒代半胱氨酸的代谢产物SeCys2的浓度达到了饱和平台，而含硒蛋白质中的总硒SeMet未发现类似现象。