Apolipoproteins as an integral part of lipoproteins are crucial for the transport and metabolism of lipids. However, there is a lack of longitudinal studies to quantify the concentrations of maternal Show more
Apolipoproteins as an integral part of lipoproteins are crucial for the transport and metabolism of lipids. However, there is a lack of longitudinal studies to quantify the concentrations of maternal apolipoproteins from preconception to postpartum and their associations with maternal metabolic health and offspring birth outcomes. Quantification of apolipoproteins was performed on maternal plasma samples (N = 243 trios) collected at preconception, 26-28 weeks' pregnancy, and three months postpartum in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO) cohort study. Linear regression models and network analysis were implemented to investigate the association of apolipoproteins with maternal genetic variants, biochemical measures, metabolic risk factors, and offspring birth outcomes. The concentrations of ApoC-III, ApoB and ApoL1 substantially increased in pregnancy compared to preconception and postpartum. Genome-wide association studies (GWAS) identified multiple single-nucleotide polymorphisms (SNPs) associated with plasma apolipoproteins (P < 5.00E-08), including APOE-rs7412 for ApoE, LPA-rs56393506 for Apo(a), APOM-rs707921 for ApoM, ABCC4-rs117797426 for ApoJ, THSD7B-rs575613 for ApoA-II, and LOC102724443-rs140433245 for ApoA-IV. Plasma apolipoproteins were strongly associated with biochemical measures including lipidomic profiles, lipoprotein features and fat-soluble vitamins, as well as metabolic risk factors including glycaemic traits, liver enzymes, inflammatory markers, albumin, and blood pressure. Integrative network analysis of apolipoproteins and their correlates/determinants revealed both shared and specific associations, with the strongest relationships observed among apolipoproteins, cholesterol, triglycerides, alpha tocopherol, and GlycA (P We describe the longitudinal landscape of maternal circulating apolipoproteins from preconception to postpartum and their associations with maternal metabolic risk factors and offspring birth outcomes. This multi-omics characterisation of biochemical correlates and genetic determinants of maternal apolipoproteins will deepen our understanding of the molecular basis of metabolic flexibility in expectant mothers, leading to better assessment of pregnancy-related outcomes. This research was supported by the Singapore National Research Foundation under its Translational and Clinical Research (TCR) Flagship Programme and administered by the Singapore Ministry of Health's National Medical Research Council (NMRC), Singapore- NMRC/TCR/004-NUS/2008; NMRC/TCR/012-NUHS/2014. The Singapore Lipidomics Incubator (SLING) is supported by grants from the National University of Singapore via the Life Sciences Institute, the National Research Foundation (NRF, NRFI2015-05 and NRFSBP-P4) and A∗STAR IAF-ICP I1901E0040. Additional funding is provided by Institute for Human Development and Potential (IHDP)-Agency for Science, Technology and Research (A∗STAR), Singapore. Show less
In randomized trials, supplementation of n-3 (ω-3) long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy has resulted in increased size at birth, which is attributable to longer gestation Show more
In randomized trials, supplementation of n-3 (ω-3) long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy has resulted in increased size at birth, which is attributable to longer gestation. We examined this finding by using a Mendelian randomization approach utilizing fatty acid desaturase (FADS) gene variants affecting LC-PUFA metabolism. As part of a tri-ethnic mother-offspring cohort in Singapore, 35 genetic variants in FADS1, FADS2, and FADS3 were genotyped in 898 mothers and 1103 offspring. Maternal plasma n-3 and n-6 PUFA concentrations at 26-28 wk of gestation were measured. Gestation duration was derived from an ultrasound dating scan in early pregnancy and from birth date. Birth length and weight were measured. Eight FADS variants were selected through a tagging-SNP approach and examined in association with PUFA concentrations, gestation duration among spontaneous labors, and birth size with the use of ethnicity-adjusted linear regressions and survival models that accounted for the competing risks of induced labor and prelabor cesarean delivery. Maternal FADS1 variant rs174546, tagging for 8 other variants located on FADS1 and FADS2, was strongly related to plasma n-6 but not n-3 LC-PUFA concentrations. Offspring and maternal FADS3 variants were associated with gestation duration among women who had spontaneous labor: each copy of rs174450 minor allele C was associated with a shorter gestation by 2.2 d (95% CI: 0.9, 3.4 d) and 1.9 d (0.7, 3.0 d) for maternal and offspring variants, respectively. In survival models, rs174450 minor allele homozygotes had reduced time to delivery after spontaneous labor compared with major allele homozygotes [HR (95% CI): 1.51 (1.18, 1.95) and 1.51 (1.20, 1.89) for mothers and offspring, respectively]. With the use of a Mendelian randomization approach, we observed associations between FADS variants and gestation duration. This suggests a potential role of LC-PUFAs in gestation duration. This trial was registered at http://www.clinicaltrials.gov as NCT01174875. Show less