Atrial natriuretic peptide level contributes to a model of future mortality in the oldest old.
OBJECTIVE
To determine if atrial natriuretic peptide (ANP) level is associated with mortality in the oldest old and to develop a comprehensive model of mortality in the oldest old using clinical and laboratory parameters.


METHODS
Prospective cohort study with 7 years of follow-up.


METHODS
A 725-bed life care facility.


METHODS
282 frail older individuals (mean age 88, range 70-102).


METHODS
Variables measured included age, gender, Charlson Comorbidity Index, functional measurements, weight, blood pressure, and multiple laboratory variables, including ANP. Main outcome measurement was death.


RESULTS
Eighty-four percent (237/282) of subjects died during the 7-year follow-up period. On univariate analysis, the risk ratio (RR) for ANP tertile was 1.28. On bivariate analysis, adjusting for the development of congestive heart failure, the RR was 1.22. On multivariate analysis, the following variables were associated with mortality: ANP tertile (RR 1.24), age (RR 1.04), female gender (RR 0.43), Charlson Comorbidity Index score (RR 1.13), mentation score (RR 1.27), BUN/Cr ratio (RR 1.04), albumin level (RR 0.63), and hemoglobin level (RR 0.84).


CONCLUSIONS
ANP level and other variables are independent risk factors for mortality in frail individuals. ANP level may indicate homeostatic failure to adapt to fluid volume changes or may reflect subclinical heart disease. ANP level contributes to a multivariate model of mortality in frail older individuals.
Knight
E L
EL
Harvard Medical School Division on Aging, and Massachusetts General Hospital, Boston 02114, USA.
Kiely
D K
DK
Fish
L C
LC
Marcantonio
E R
ER
Minaker
K L
KL
D000368:Aged; D000369:Aged, 80 and over; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001794:Blood Pressure / Q000502:physiology; D001806:Blood Urea Nitrogen; D002908:Chronic Disease / Q000401:mortality*; D015897:Comorbidity; D016001:Confidence Intervals; D003404:Creatinine / Q000097:blood; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data*; D015577:Geriatric Assessment; D006339:Heart Rate / Q000502:physiology; D006452:Hemoglobinometry; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D015233:Models, Statistical; D012306:Risk; D012709:Serum Albumin / Q000378:metabolism; D016019:Survival Analysis
D012709:Serum Albumin; D009320:Atrial Natriuretic Factor; D003404:Creatinine