title: Impact of age, phenotype and cardio-renal function on plasma C-type and B-type natriuretic peptide forms in an adult population.
abstract: BACKGROUND
  In contrast to the cardiac hormones, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), variations in plasma concentrations of C-type natriuretic peptide (CNP) in healthy adults are ill-defined, limiting their clinical application.
  
  
  OBJECTIVE
  Our objective was to define the effect of age, phenotype (gender, height, BMI), and cardiac and renal function on plasma CNPs in an adults population without renal or cardiovascular disease.
  
  
  METHODS
  This was a prospective cross-sectional observational study of adult volunteers, aged 21-80 years, randomly selected from the electoral roll.
  
  
  METHODS
  Plasma CNP and its associated aminoterminal propeptide (NTproCNP) were measured in 258 subjects and related to age, gender, height and plasma creatinine. Subgroup analyses seeking associations with cardiac function (plasma BNP and NTproBNP) and bone turnover bone-specific alkaline phosphatase (bALP) were also determined.
  
  
  RESULTS
  Plasma concentrations of CNPs in men continued to decline from adolescent values to reach a nadir in the 5th decade after which values increased. Similar but less marked changes occurred in women. In both sexes, NTproCNP was inversely and independently correlated with height. In contrast to B-type natriuretic peptides (BNPs), NTproCNP was higher in men, significantly related to creatinine and positively related to bALP.
  
  
  CONCLUSIONS
  Gender- and age-specific changes affect CNPs in adults. Inverse associations of NTproCNP with adult height, positive correlation with creatinine - and in contrast to CNP - no association with BNP are further unique findings distinguishing NTproCNP, which need to be considered in future studies.
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand. tim.prickett@otago.ac.nz
authors.forename: T C R
authors.initials: TC
authors.lastname: Prickett
authors.forename: R C
authors.initials: RC
authors.lastname: Olney
authors.forename: V A
authors.initials: VA
authors.lastname: Cameron
authors.forename: M J
authors.initials: MJ
authors.lastname: Ellis
authors.forename: A M
authors.initials: AM
authors.lastname: Richards
authors.forename: E A
authors.initials: EA
authors.lastname: Espiner
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D020098:Natriuretic Peptide, C-Type / Q000097:blood*; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D020097:Natriuretic Peptide, Brain; D020098:Natriuretic Peptide, C-Type