The prognostic capacity of B-type natriuretic peptide on cognitive disorder varies by age.

Introduction: 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.