The prognostic capacity of B-type natriuretic peptide on cognitive disorder varies by age.
BACKGROUND
It is known that blood levels of natriuretic peptides associate with cognitive disorder among the middle-aged. We aimed to test whether this association is valid in an older population aged 75 years or older.


METHODS
A total of 601 older subjects aged 75 or older participated in the study. A subgroup of 137 with a diagnosed cognitive disorder were tested for natriuretic peptides (ANP, NT-proANP, and BNP), and compared with age-matched controls (n = 464). The control group was followed-up for 5 years, and the association of the baseline BNP with the occurrence of cognitive impairment was studied.


RESULTS
In the youngest age tertile (75-78 y), BNP was significantly associated with a diagnosed cognitive disorder when other factors with a known effect on natriuretic peptides were taken into account. In the oldest tertile (83-96 y), higher BNP values suggested the absence of cognitive dysfunction. ANP and NT-proANP did not associate with the presence of cognitive impairment. Among the control group, BNP predicted a cognitive disorder at follow-up, but only in the youngest tertile.


CONCLUSIONS
The previously found link between a high BNP concentration and cognitive disorder in older people is only valid among those aged less than 79 years.
Department of Clinical Neurophysiology, Helsinki University Central Hospital, FI-00290 Helsinki, Finland.
Matti
M
Hiltunen
Tuomas
T
Kerola
Raimo
R
Kettunen
Sirpa
S
Hartikainen
Raimo
R
Sulkava
Olli
O
Vuolteenaho
Tuomo
T
Nieminen
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood*; D000704:Analysis of Variance; D009320:Atrial Natriuretic Factor / Q000097:blood; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000097:blood*; D015140:Dementia, Vascular / Q000097:blood*; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000097:blood*; D008297:Male; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis
D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor