title: Within-subject variation of plasma resistin levels over a 1-year period.
abstract: BACKGROUND
  Resistin, a recently discovered hormone, is purportedly involved in metabolic and inflammatory processes in humans and may thus be an important marker to assess disease risk in large-scale epidemiological studies.
  
  
  METHODS
  We assessed the reliability of human resistin levels in 63 men and 51 women aged 35-67 years with repeated measurements of resistin over a period of 1 year. Student's paired t-test was used to compare resistin concentrations at baseline and 1 year later. Intraclass correlation coefficients (ICCs) were calculated by analysis of variance.
  
  
  RESULTS
  There was no significant difference between resistin concentrations at baseline and after 1 year for both sexes combined or when analyzed separately for men and women. The ICCs were 0.70 (95% CI 0.59-0.78) for both sexes combined, 0.75 (95% CI 0.62-0.84) for men, and 0.66 (95% CI 0.47-0.79) for women. Resistin levels were not significantly related to age, body mass index, waist-to-hip ratio, sex, or fasting status.
  
  
  CONCLUSIONS
  Individual blood resistin concentrations did not significantly change over a period of 1 year, but showed a high degree of reliability. Our findings suggest that a single resistin measurement may be sufficient for risk assessment in epidemiological studies.
authors.affiliation: German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany. weikert@mail.dife.de
authors.forename: Cornelia
authors.initials: C
authors.lastname: Weikert
authors.forename: Sabine
authors.initials: S
authors.lastname: Westphal
authors.forename: Claus
authors.initials: C
authors.lastname: Luley
authors.forename: Stefan N
authors.initials: SN
authors.lastname: Willich
authors.forename: Heiner
authors.initials: H
authors.lastname: Boeing
authors.forename: Tobias
authors.initials: T
authors.lastname: Pischon
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D052243:Resistin / Q000097:blood*; D012307:Risk Factors; D012727:Sex Characteristics; D049629:Waist-Hip Ratio
chemical_list: D015415:Biomarkers; C499624:RETN protein, human; D052243:Resistin