Maternal Urinary Phthalate Metabolites are Associated with Lipidomic Signatures Among Pregnant Women in Puerto Rico

BACKGROUND: Phthalates have been reported to alter circulating lipid concentrations in animals, and investigation of these associations in humans will provide greater understanding of potential mechanisms for health outcomes. OBJECTIVE: to explore associations between phthalate metabolite biomarkers and lipidomic profiles among pregnant women (n = 99) in the Puerto Rico PROTECT cohort. METHODS: We measured 19 urinary phthalate metabolites during 24–28 weeks of pregnancy. Lipidomic profiles were identified from plasma samples by liquid chromatography-mass spectrometry-based shotgun lipidomics. Relationships between phthalate metabolites and lipid profiles were estimated using compound-by-compound comparisons in multiple linear regression and dimension reduction techniques. We derived sums for each lipid class and sub-class (saturated, monounsaturated, polyunsaturated) which were then regressed on phthalate metabolites. Associations were adjusted for false discovery. RESULTS: After controlling for multiple comparisons, 33 phthalate-lipid associations were identified (False discovery rate adjusted p-value<0.05), and diacylglycerol 40:7 and plasmenyl-phosphatidylcholine 35:1 were the most strongly associated with multiple phthalate metabolites. Metabolites of di-2-ethylhexyl phthalate, bis(2-ethylhexyl) phthalate, dibutyl phthalates, and diisobutyl phthalate were associated with increased ceramides, lysophosphatidylcholines, lysophosphatidylethanolamines, and triacylglycerols, particularly those containing saturated and monounsaturated fatty acid chains. SIGNIFICANCE: Characterization of associations between lipidomic markers and phthalate metabolites during pregnancy will yield mechanistic insight for maternal and child health outcomes.