B‐type natriuretic peptide and severity of cognitive disorder

BACKGROUND: Natriuretic peptides have been linked to cognitive disorder in previous studies. The aim of this study was to examine the association between the severity of cognitive disorder and the levels of B-type natriuretic peptide (BNP) in an older general population. MATERIAL AND METHODS: This study is a part of the larger population-based, multidisciplinary Kuopio 75+ health study. A total of 601 subjects aged 75 or older participated in the study. A subgroup of 126 individuals was diagnosed with cognitive disorder, and the severity of the disease was assessed. The participants were tested for BNP. Analysis of covariance was carried out to study the relationship between BNP and the stage of cognitive disorder. RESULTS: The association between the level of cognitive disorder and BNP resembled an inverse U-shaped curve, with higher levels of BNP observed among participants with mild cognitive disorder when compared to cognitively intact participants or counterparts with more severe cognitive disorder. This effect remained after adjustment for age (P = 0.02). However, association between BNP and level of cognitive disorder was lost in further adjustment with covariates connected to the levels of BNP. CONCLUSION: The previously reported elevation of natriuretic peptides among individuals with diagnosed cognitive disorder was found only in people with milder stages of the disorder.