title: RBP4 variants are significantly associated with plasma RBP4 levels and hypertriglyceridemia risk in Chinese Hans.
abstract: We previously found that plasma RBP4 levels were strongly associated with metabolic syndrome components. This study aimed to determine whether RBP4 variants are associated with the metabolic syndrome components and plasma RBP4 levels, and to investigate whether the associations between plasma RBP4 and the metabolic syndrome components are causal. Five tagSNPs were tested for their associations with plasma RBP4 levels and metabolic syndrome components in a population-based sample of 3,210 Chinese Hans. A possible causal relationship between plasma RBP4 levels and hypertriglyceridemia was explored by Mendelian randomization. Plasma RBP4 levels were significantly associated with rs10882273 (betaz -0.10SD[-0.17, -0.03], P = 0.0050), rs3758538 (betaz -0.13SD[-0.24, -0.02], P = 0.0249) in all participants, and with rs17108993 in Shanghai participants (betaz -0.19SD[-0.32, -0.05], P = 0.0061). The single nucleotide polymorphism (SNP) rs3758538 was significantly associated with hypertriglyceridemia (OR 0.62[0.45-0.85], P = 0.0026) and triglycerides (betaz -0.19SD[-0.30, -0.07], P = 0.001) in all participants. In Mendelian randomization analysis, the observed effect size of association between rs3758538 and hypertriglyceridemia was different from the expected effect size (P = 0.0213). This is the first study to show that the RBP4 variants are significantly associated with plasma RBP4 levels and hypertriglyceridemia risk in Chinese Hans. However, results of Mendelian randomization do not support the hypothesis that RBP4 levels are causally related to hypertriglyceridemia risk.
authors.affiliation: Key Laboratory of Nutrition and Metabolism, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Graduate School of the Chinese Academy of Sciences, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Huaixing
authors.initials: H
authors.lastname: Li
authors.forename: Ruth J F
authors.initials: RJ
authors.lastname: Loos
authors.forename: Qibin
authors.initials: Q
authors.lastname: Qi
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Xu
authors.initials: X
authors.lastname: Lin
mesh_terms: D044466:Asian People / Q000235:genetics*; D002681:China; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood / Q000235:genetics; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000235:genetics; D011897:Random Allocation; D054839:Retinol-Binding Proteins, Plasma / Q000235:genetics / Q000378:metabolism; D012307:Risk Factors
chemical_list: C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma