title: C-reactive protein in adolescent twins: patterns and relationship to adiposity.
abstract: BACKGROUND
  Elevated C-reactive protein (CRP) is a marker of cardiovascular risk in adults. Patterns and determinants of CRP in adolescents have not been well described.
  
  
  OBJECTIVE
  This study aimed to determine how CRP varies by age, gender, Tanner stage, and body fat composition in rural Chinese adolescents and to what degree adiposity-CRP associations are attributable to shared genetic and environmental factors.
  
  
  METHODS
  Data were derived from an ongoing study of metabolic syndrome in a large community-based twin cohort enrolled in Anqing, China.
  
  
  METHODS
  The study sample included 1180 adolescent twins aged 13-21 yr.
  
  
  METHODS
  Plasma CRP concentrations were measured by sandwich immunoassay using flow metric xMAP technology. Body fat composition was assessed by dual-energy x-ray absorptiometry.
  
  
  RESULTS
  CRP levels linearly increased across age and Tanner stage in males (P ≤ 0.0001), but in females, CRP exhibited no trend after adjusting for fat mass (P > 0.05). For males, the most explanatory measure was body mass index (partial r(2) = 5.2%), whereas percent body fat (partial r(2) = 8.8%) was more explanatory in females. Of the phenotypic correlations between adiposity measures and CRP (0.25-0.28), 86-89% were attributed to shared genetic factors and 11-14% to common unique environmental factors in both sexes.
  
  
  CONCLUSIONS
  Adiposity is a strong determinant of CRP even in this relatively lean Chinese population. There is notable gender difference for the CRP pattern and the relationship of CRP with adiposity during adolescence. To a large degree, common genetic factors may underlie the observed adiposity-CRP-phenotypic correlations.
authors.affiliation: Mary Ann and J Milburn Smith Child Health Research Program, Northwestern University Feinberg School of Medicine and Children's Memorial Hospital and Children's Memorial Research Center, Chicago, Illinois 60614, USA.
authors.forename: Guoying
authors.initials: G
authors.lastname: Wang
authors.forename: Katherine Kaufer
authors.initials: KK
authors.lastname: Christoffel
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Brickman
authors.forename: Xiumei
authors.initials: X
authors.lastname: Hong
authors.forename: Lester
authors.initials: L
authors.lastname: Arguelles
authors.forename: Shanchun
authors.initials: S
authors.lastname: Zhang
authors.forename: Binyan
authors.initials: B
authors.lastname: Wang
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Li
authors.forename: Houxun
authors.initials: H
authors.lastname: Xing
authors.forename: Gengfu
authors.initials: G
authors.lastname: Tang
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: D015502:Absorptiometry, Photon; D050154:Adiposity / Q000235:genetics / Q000502:physiology*; D000293:Adolescent; D000375:Aging / Q000502:physiology; D000886:Anthropometry; D044466:Asian People; D001823:Body Composition / Q000235:genetics / Q000502:physiology; D002097:C-Reactive Protein / Q000378:metabolism*; D004777:Environment; D005260:Female; D006801:Humans; D007118:Immunoassay; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology / Q000235:genetics; D011627:Puberty; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein