Circulatory metabolomics reveals the association of the metabolites with clinical features in the patients with intrahepatic cholestasis of pregnancy

OBJECTIVE: Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of adverse pregnancy outcomes to the mother and fetus. As yet, the metabolic profiles and the association of the clinical features remain obscure.
METHODS: Fifty seven healthy pregnant women and 52 patients with ICP were recruited in this study. Plasma samples were obtained from pregnancies who received prenatal care between the 30-36 weeks. Untargeted metabolomics to portray metabolic profiles were performed by LC/MS. Mul- combined with univariate data analysis and statistical analysis were performed to select differential metabolites between ICP and control group. Debiased sparse partial correlation (DSPC) network analysis of differential metabolites was performed to explore the potential mutual regulation among metabolites on the basis of de-sparsified graphical lasso modeling procedure. Pathway analysis was performed using MetaboAnalyst. Linear regression and Pearson correlation analysis were applied to analyze correlations associated with bile acid levels, metabolites, newborn weight and pregnancy outcome in ICP patients.
RESULTS: Conspicuous metabolic changes and choreographed metabolic profiles were disclosed: 125 annotated metabolites and eighteen metabolic pathways were disturbed in ICP patients. DSPC networks indicated dense interactions among amino acids and their derivatives, bile acids, carbohydrates and organic acids. The levels of total bile acid were increased in ICP patients with meconium-stained amniotic fluid compared with those without MSAF. Abnormal tryptophan metabolism, elevated long chain saturated fatty acid and estrone sulfate levels, and low antioxidant capacity were relevant to increasing bile acid levels. Correlation analysis showed that newborn body weights were significant correlated with the levels of several bile acids and some metabolites of amino acids.
CONCLUSION: The ICP patient showed metabolic disorder, and the levels of a number of metabolites were correlated with TBA levels and neonatal body weights. These results provide us important information to further understand the metabolic characteristics of patients with ICP and adverse pregnancy outcomes.

研究目的：妊娠期肝内胆汁淤积症（Intrahepatic cholestasis of pregnancy, ICP）可增加母婴不良妊娠结局的发生风险，目前其代谢谱特征及与临床表型的关联仍不明确。
方法：本研究共纳入57名健康孕妇与52名ICP患者。于孕30~36周接受产前检查时采集血浆样本，采用液相色谱-质谱联用（LC/MS）进行非靶向代谢组学分析，以刻画整体代谢谱。通过单变量数据分析结合多变量统计分析，筛选ICP组与对照组的差异代谢物。基于去稀疏化图套索建模流程，对差异代谢物开展去偏稀疏偏相关（Debiased sparse partial correlation, DSPC）网络分析，以探究代谢物间潜在的相互调控关系。采用MetaboAnalyst进行代谢通路富集分析。通过线性回归与Pearson相关分析，探究ICP患者体内胆汁酸水平、代谢物、新生儿体重与妊娠结局之间的关联。
结果：本研究揭示了ICP患者显著的代谢改变与特征性代谢谱：共计125种注释代谢物及18条代谢通路在ICP患者体内发生紊乱。DSPC网络分析显示，氨基酸及其衍生物、胆汁酸、糖类与有机酸之间存在密集的相互作用。相较于未伴胎粪污染羊水（meconium-stained amniotic fluid, MSAF）的ICP患者，伴MSAF的ICP患者总胆汁酸（Total Bile Acid, TBA）水平显著升高。色氨酸代谢异常、长链饱和脂肪酸及雌酮硫酸盐水平升高，以及抗氧化能力下降，均与胆汁酸水平升高密切相关。相关性分析结果表明，新生儿体重与多种胆汁酸及部分氨基酸代谢物水平存在显著关联。
结论：本研究证实ICP患者存在代谢紊乱，且多种代谢物水平与总胆汁酸（TBA）水平及新生儿体重显著相关。上述结果为进一步阐明ICP患者的代谢特征及不良妊娠结局的发生机制提供了重要依据。