Plasma brain natriuretic peptide level in older outpatients with heart failure is associated with physical frailty, especially with the slowness domain.
OBJECTIVE
To determine the association between plasma brain natriuretic peptide (BNP) level in patients with heart failure (HF) and physical frailty as well as with each domain of physical frailty.


METHODS
Two hundred and six outpatients of cardiovascular medicine aged 60 years and older who had been hospitalized for HF or had been given a prescription medication for HF were included. Physical frailty was assessed using the following five domains: slowness, weakness, exhaustion, low activity, and shrinking, according to the Cardiovascular Health Study. Patients were divided into nonfrailty and frailty groups according to frailty scores. Plasma BNP level was measured. The 6-min walk test was performed to measure endurance.


RESULTS
Plasma BNP was significantly different between the two groups (frailty group: 158.0 ± 214.7 pg/mL, nonfrailty group: 65.2 ± 88.0 pg/mL, P < 0.01). Multivariate logistic regression analysis revealed log-transformed plasma BNP (Log BNP) was significantly associated with physical frailty (OR: 1.68, 95% CI: 1.11-2.56), and Log BNP was significantly associated with the slowness domain (walking speed < 1.0 m/s) of physical frailty (OR: 1.75, 95% CI: 1.15-2.67). Additionally, Log BNP was negatively correlated to the 6-minute walk distance (6MWD) (ρ = -0.37, P < 0.01), while 6MWD was positively correlated to walking speed (ρ = 0.66, P < 0.01).


CONCLUSIONS
Plasma BNP level was related to physical frailty, especially in the slowness domain. Endurance may intervene in the associations between plasma BNP level and walking speed.
Department of Physical Therapy, School of Health Sciences, Tokyo University of Technology, Tokyo, Japan.
Shu
S
Nishiguchi
Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Yuma
Y
Nozaki
Department of Cardiovascular Medicine, Koto Memorial Hospital, Shiga, Japan.
Masayuki
M
Yamaji
Department of Rehabilitation Unit, Koto Memorial Hospital, Shiga, Japan.
Kanako
K
Oya
Department of Rehabilitation Unit, Koto Memorial Hospital, Shiga, Japan.
Yuki
Y
Hikita
Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Tomoki
T
Aoyama
Department of Cardiovascular Medicine, Koto Memorial Hospital, Shiga, Japan.
Hiroshi
H
Mabuchi
Brain natriuretic peptide; Heart failure; Physical frailty; Walking speed