title: Atrial natriuretic peptide levels in the elderly: differentiating normal aging changes from disease.
abstract: BACKGROUND
  Atrial natriuretic peptide (ANP) levels increase with advancing age and in patients with cardiac dysfunction. Previous studies have failed to differentiate the elevated ANP levels of normal aging from those of cardiac disease.
  
  
  METHODS
  To differentiate the increased ANP levels seen in normal aging from that of disease, fasting supine ANP was measured in healthy young (n = 24), healthy old (n = 90), and clinically stable but cardiovascularly diseased old (n = 269) residents of a life care facility. ANP levels were correlated with physical exam findings, blood chemistries, measures of physical and cognitive function, and medications.
  
  
  RESULTS
  ANP levels were almost fourfold higher in the healthy elderly than in the young (11.4 +/- 1.1 (SEM) vs 3 +/- 0.3 pmol/L, p < .01), and two-and-one-half times higher in the cardiovascular-diseased elderly than the healthy elderly (29 +/- 1.9 vs 11.4 +/- 1.1 pmol/L, p < .01). An ANP value of 21 pmol/L has a sensitivity of 83% and specificity of 52% in distinguishing those elders classified as healthy from those classified as having chronic cardiovascular disease. ANP levels had positive univariate correlation with age (even from 70 to 102 years) and systolic blood pressure. ANP rose progressively with increasing numbers of markers of cardiovascular comorbidity. ANP was higher in subjects with jugular venous pressure > 10 cm, presence of a third heart sound, peripheral edema, artificial cardiac pacemaker, atrial arrhythmias, and in those taking digoxin, diuretics, or nitrates. On multivariate analysis independent predictors of ANP levels were, in descending order, nitrates, age, diuretics, and atrial arrhythmias.
  
  
  CONCLUSIONS
  These data suggest that ANP levels greater than 21 pmol/L are associated with cardiovascular comorbidity in a clinically stable elderly cohort.
authors.affiliation: Department of Geriatrics, North Mississippi Medical Center, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Davis
authors.forename: L C
authors.initials: LC
authors.lastname: Fish
authors.forename: K L
authors.initials: KL
authors.lastname: Minaker
authors.forename: D
authors.initials: D
authors.lastname: Elahi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D009320:Atrial Natriuretic Factor / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood; D006801:Humans
chemical_list: D009320:Atrial Natriuretic Factor