title: Genetic and environmental contributions to phenotypic components of metabolic syndrome: a population-based twin study.
abstract: The increasing prevalence of metabolic syndrome (MS) poses a serious public-health problem worldwide. Effective prevention and intervention require improved understanding of the factors that contribute to MS. We analyzed data on a large twin cohort to estimate genetic and environmental contributions to MS and to major MS components and their intercorrelations: waist circumference (WC), systolic (SBP) and diastolic blood pressure (DBP), fasting plasma glucose (FPG), triglycerides (TGs), and high-density lipoprotein-cholesterol (HDL-C). We applied structural equation modeling to determine genetic and environmental structure of MS and its major components, using 1,617 adult female twin pairs recruited from rural China. The heritability estimate for MS was 0.42 (95% confidence interval (CI): 0.00-0.83) in this sample with low MS prevalence (4.4%). For MS components, heritability estimates were statistically significant and ranged from 0.13 to 0.64 highest for WC, followed by TG, SBP, DBP, HDL-C, and FPG. HDL-C was mainly influenced by common environmental factors (0.62, 95% CI: 0.58-0.62), whereas the other five MS components were largely influenced by unique environmental factors (0.32-0.44). Bivariate Cholesky decomposition analysis indicated that the clinical clustering of MS components may be explained by shared genetic and/or environmental factors. Our study underscores the importance of examining MS components as intercorrelated traits, and to carefully consider environmental and genetic factors in studying MS etiology.
authors.affiliation: Mary Ann and J. Milburn Smith Child Health Research Program, Department of Pediatrics, Northwestern University Feinberg School of Medicine and Children's Memorial Hospital and Children's Memorial Research Center, Chicago, Illinois, USA.
authors.forename: Shanchun
authors.initials: S
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Yunxian
authors.initials: Y
authors.lastname: Yu
authors.forename: Xiumei
authors.initials: X
authors.lastname: Hong
authors.forename: Katherine K
authors.initials: KK
authors.lastname: Christoffel
authors.forename: Binyan
authors.initials: B
authors.lastname: Wang
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Tsai
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Li
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.forename: Genfu
authors.initials: G
authors.lastname: Tang
authors.forename: Houxun
authors.initials: H
authors.lastname: Xing
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Brickman
authors.forename: Donald
authors.initials: D
authors.lastname: Zimmerman
authors.forename: Xiping
authors.initials: X
authors.lastname: Xu
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000328:Adult; D001794:Blood Pressure; D002681:China; D008076:Cholesterol, HDL / Q000378:metabolism; D004200:Diseases in Twins; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D024821:Metabolic Syndrome / Q000209:etiology / Q000235:genetics*; D008875:Middle Aged; D010641:Phenotype; D013599:Systole; D014280:Triglycerides / Q000378:metabolism
chemical_list: D008076:Cholesterol, HDL; D014280:Triglycerides