title: Brain natriuretic peptide as a potential novel marker of salt-sensitivity in chronic kidney disease patients without cardiac dysfunction.
abstract: Although the renin-angiotensin system (RAS) is counter-balanced by a salt-sensitive mechanism in the hypertensive state, both are reported to be up-regulated in chronic kidney disease (CKD) patients. We conducted this study to evaluate the associations among the RAS, renal function, hypertension, and atherosclerosis, as well as to identify markers for salt-sensitivity. A total of 213 pre-dialysis CKD patients with preserved cardiac function (EF >50 %) were enrolled. Their renal and cardiac biochemical markers and plasma renin activity (PRA) were measured, and echocardiography and carotid artery ultrasound were performed. Their salt intake was estimated by the NaCl excretion from a 24-h collected urine sample. The PRA was higher in patients with hypertension (p = 0.018), and had a significant negative correlation with the eGFR (r = -0.23, p = 0.0067). Importantly, the PRA had a strong negative correlation with the brain natriuretic peptide (BNP) level (r = -0.28, p = 0.017) regardless of whether the patients were being treated with RAS inhibitors. The BNP level was related to the renal functions (eGFR: p = 0.001, ACR: p = 0.009). There was a significant positive correlation between the BNP level and carotid intima-media thickness (p < 0.001). A multivariate analysis revealed that older age and an excess of NaCl excretion were independent predictors of BNP elevation (p = 0.02 and 0.003, respectively). Our analysis revealed details of the counterbalance between BNP and PRA, as well as identifying that excess salt intake is a predictor of BNP elevation. These results indicate that the BNP could be a possible valuable marker for salt sensitivity, and that high salt sensitivity could facilitate atherosclerosis in CKD patients.
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan. muhayasi@fujita-hu.ac.jp.|Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. muhayasi@fujita-hu.ac.jp.
authors.forename: Mutsuharu
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Yasuda
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Manaka
authors.initials: M
authors.lastname: Tagaya
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Tomohito
authors.initials: T
authors.lastname: Kamada
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Yoshinaga
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Sugishita
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Wakaya
authors.initials: W
authors.lastname: Fujiwara
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Hiroatsu
authors.initials: H
authors.lastname: Yokoi
authors.affiliation: Department of Cardiology, Fujita Health University Hospital, Toyoake, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ozaki
authors.affiliation: Department of Cardiology, Fujita Health University Banbuntane Hotokukai Hospital, 3-6-10 Otobashi, Nakagawa-ku, Nagoya, 454-8509, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Izawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D059168:Carotid Intima-Media Thickness; D004452:Echocardiography; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000097:blood*; D007564:Japan; D007668:Kidney / Q000378:metabolism; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications*; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System; D012982:Sodium, Dietary / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D012982:Sodium, Dietary; D020097:Natriuretic Peptide, Brain; D012083:Renin
keywords: Brain natriuretic peptide (BNP); Chronic kidney disease (CKD); Intima–media thickness (IMT); Plasma renin activity (PRA); Salt sensitivity