2011—2013年中国母乳骨桥蛋白含量及相关因素

Concentration of osteopontin in human milk and associated factors in Chinese populations from 2011 to 2013

目的了解中国不同人群母乳骨桥蛋白(osteopontin, OPN)含量并分析其相关因素。方法基于2011—2013年中国母乳成分数据库项目样本和数据,按泌乳阶段分层后,随机抽取共459名研究对象,采用超高效液相色谱-串联质谱法测定母乳OPN。结果母乳OPN浓度[M(P25,P75)]为44.0(30.1,72.0)mg/L,初乳、过渡乳及成熟乳OPN浓度分别为45.6(31.8,80.7)、41.3(29.2,70.0)和46.9(30.2,71.9)mg/L。OPN占母乳总蛋白质比例分别为0.40%、0.42%和0.65%。各泌乳阶段母乳中OPN浓度接近,占母乳总蛋白比例呈现随着泌乳阶段延长增加的趋势(r=0.21,P<0.001)。多因素分析结果显示,近一周的睡眠质量与母乳OPN水平相关(P=0.04),睡眠质量高的乳母乳中OPN水平明显高于睡眠质量差的乳母(46.5 mg/L vs. 34.7 mg/L)。云南地区母乳OPN平均水平高于北京地区(50.5 mg/L vs. 36.1 mg/L,P=0.03)。母亲年龄、分娩方式、孕前体质指数、孕期增重、被动吸烟以及过去24小时户外活动与母乳中OPN含量均无明显相关性。婴儿早产、过去2周婴儿发生腹泻、呼吸系统疾病或过敏性疾病与母乳中OPN浓度无关。结论中国人乳OPN在不同泌乳阶段含量相近,地区及睡眠质量与母乳中OPN水平相关。

OBJECTIVE To analyze content of human milk osteopontin(OPN) and to explore associated factors in Chinese populations. METHODS The samples and data were extracted from the database for human milk composition in China between 2011 and 2013. A sub-sample of 459 mothers was randomly selected after stratification according to lactation stage, and human milk OPN concentrations were determined by ultra performance liquid chromatography-tandem mass spectrometer(UPLC/MS). RESULTS The average OPN concentration(M(P25,P75)) in breast milk was 44.0(30.1-72.0) mg/L within 0-330 days postpartum. OPN concentrations were independent of lactation stage, which were 45.6(31.8, 80.7) mg/L in colostrum, 41.3(29.2, 70.0) mg/L in transitional milk and 46.9(30.2, 71.9) mg/L in mature milk, corresponding to 0.40%、0.42% and 0.65% of the total milk protein content(OPN/protein%). The percentage of OPN to total protein in milk showed an increasing trend with lactation progression(r=0.21, P<0.001). Multivariate analysis showed that sleep quality of mothers within one week prior to milk collection was correlated with the breast milk OPN level(P=0.04). The OPN level in breast milk from mothers with good sleep quality was significantly higher than that from mothers with poor sleep quality(46.5 mg/L vs. 34.7 mg/L). The median level of milk OPN concentration in mothers from Yunnan was higher than mothers from Beijing(50.5 mg/L vs. 36.1 mg/L, P=0.03). Maternal age, mode of delivery, prepregnancy body mass index, weight gain during pregnancy, passive smoking and outdoor activities 24 hours prior to milk collection were not correlated with milk OPN concentration. OPN concentration in breast milk was not related to preterm birth. Also, milk OPN concentration did not correlate with diarrhoea, respiratory disease, or allergic disease in infants during two weeks before milk collection. CONCLUSIONThe concentration of OPN in breast milk of Chinese woman may be similar among different lactation stages. Geographic region and sleep quality of mothers may be related to the milk OPN concentration.