Proatrial natriuretic polypeptide (31-67) in healthy individuals: day-to-day variation and influence of sex and age.
N-terminal parts of proatrial natriuretic polypeptide have been proposed to be sensitive and specific markers of congestive heart failure (CHF). A prerequisite for use of a clinical marker is knowledge of day-to-day variation and dependence on age and sex. Immunoreactive N-terminal proatrial natriuretic polypeptide (31-67) (ir-N-ANP(31-67)) was measured in a clinically relevant population of healthy individuals. A total of 21 females (mean age 52 years, range 42-76) and 26 males (mean age 54 years, range 42-73), without cardiovascular disease, were included in the study. No correlation was found between ir-N-ANP(31-67) and sex. A statistically significant positive linear correlation (ir-N-ANP pmol 1(-1) = 182+ (8.2 x age in years) (p = 0.004) was found between age and ir-N-ANP(31-67). For the youngest subjects (42 years) the expected mean ir-N-ANP(31-67) was 530 pmol 1(-1), and for the oldest subjects (76 years) it was 800 pmol 1(-1). For all the subjects, the median ir-N-ANP(31-67) was found to be 626 pmol 1(-1) (range 300-1151). The day-to-day variation was studied and no significant difference was found in the plasma concentration of two samples taken 2-5 days apart. Of the individual day-to-day variation, 95% would be expected to be in the interval from -244 to 188 pmol 1(-1) (mean +/- 2 x SD). We conclude that ir-N-ANP(31-67) rises with age. The age-dependent rise in ir-N-ANP(31-67) is modest, but should be taken into consideration in order to use ir-N-ANP(31-67) as a diagnostic marker of CHF. The day-to-day variation is found to be rather high and cannot be neglected if N-ANP(31-67) is to be used as a marker of asymptomatic heart failure.
Department of Clinical Chemistry, Aalborg Hospital, Denmark.
J B
JB
Hansen
G
G
Nielsen
J
J
Aarøe
D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood; D009320:Atrial Natriuretic Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006333:Heart Failure / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*; D012016:Reference Values; D015203:Reproducibility of Results; D012727:Sex Characteristics
D015415:Biomarkers; D010446:Peptide Fragments; D011498:Protein Precursors; C054548:atrial natriuretic factor prohormone (31-67); D009320:Atrial Natriuretic Factor