title: Long-term C-reactive protein variability and prediction of metabolic risk.
abstract: OBJECTIVE
  This analysis was undertaken to determine the long-term intraindividual variability, determinants of change, and capacity of the inflammatory marker C-reactive protein (CRP) to predict metabolic traits and diabetes in a large community-based population.
  
  
  METHODS
  Intraindividual CRP variability, predictors of CRP change, and metabolic events were evaluated in the Framingham Heart Study Offspring cohort using data from the same 2409 participants with CRP measured by the same methodology at each of 3 examination cycles, spanning 20 years.
  
  
  RESULTS
  Between the first and second examinations (averaging 16 years apart), 23% to 47% of men and 27% to 49% of women remained within the same quintile of CRP values. An additional 24% to 51% of men and 24% to 50% of women occupied an adjacent quintile. Intermediate-term CRP variability (over 4 years) was similar to long-term variability. Both long- and intermediate-term variability of CRP were significantly less than that of plasma cholesterol measured in these same groups. Linear regression models for CRP at the intermediate examination demonstrated that CRP at the initial examination contributed the largest proportion of the variability (partial R-square = 0.27) seen in the overall model after adjustment for other covariates known to affect CRP concentrations. Although logistic regression models demonstrated that CRP over the intermediate term did not predict new-onset metabolic syndrome at the final examination, CRP did predict an increase in glucose and new-onset diabetes.
  
  
  CONCLUSIONS
  The results of this longitudinal analysis suggest the intraindividual, long-term variability of CRP concentrations is relatively small and predictive of new diabetes over an intermediate-term of 4 years.
authors.affiliation: The Framingham Heart Study and Boston University School of Medicine, Framingham, Mass, USA.
authors.forename: Ting-hsu
authors.initials: TH
authors.lastname: Chen
authors.forename: Philimon
authors.initials: P
authors.lastname: Gona
authors.forename: Patrice A
authors.initials: PA
authors.lastname: Sutherland
authors.forename: Emelia J
authors.initials: EJ
authors.lastname: Benjamin
authors.forename: Peter W F
authors.initials: PW
authors.lastname: Wilson
authors.forename: Martin G
authors.initials: MG
authors.lastname: Larson
authors.forename: Ramachandran S
authors.initials: RS
authors.lastname: Vasan
authors.forename: Sander J
authors.initials: SJ
authors.lastname: Robins
mesh_terms: D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000097:blood* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012727:Sex Characteristics; D013997:Time Factors
chemical_list: D002097:C-Reactive Protein