Abstract 10011: Brain Natriuretic Peptide as a Noble Marker of a Salt-sensitivity in Chronic Kidney Disease Patients without Cardiac Dysfunction
Background: Though renin-angiotensin system (RAS) is counterbalanced by a salt-sensitivity in hypertensive state, both were reported to be up-regulated in CKD patients. To investigate the interaction is valuable for the treatment, but a useful marker of a salt-sensitivity has not been established. In this study, we investigated the candidates for a salt-sensitive marker, and the relation with RAS and the atherosclerosis.
Methods: Consecutive 213 pre-dialysis CKD patients without contractile cardiac dysfunction (ejection fraction (EF) >40%) were enrolled, and measured estimated glomerular filtration rate (eGFR), uremic albumin creatinine ratio (ACR), plasma renin activity (PRA), aldosterone, BNP and hs-CRP. The extent of atherosclerosis was elucidated by carotid intima-media thickness (IMT). Echocardiograms were performed and measured EF, E/A and left ventricular mass index (LVMI) as markers of cardiac function. We analyses the relations between cardiac, renal function and hormonal markers cross-sectionaly.
Results: Mean eGFR was 41.4±18.9ml/min/1.73m2, and patients with hypertension (HT) was 79.3%. In patients with HT, ACR,PRA,BNP and LVMI were significant higher compare to patients without HT (p=0.012, 0.018, 0.0014, 0.003, respectively). About RAS, PRA had a significant negative correlation with eGFR (r=-0.23,p=0.0067), as previously reported. Of importance, PRA had a good negative correlation with BNP (r=-0.28,p=0.017), nevertheless no relation with EF, E/A and LVMI. Similar tendencies were found regardless of RAS blockers intake. BNP level was higher than healthy (mean BNP: 58.2±108 pg/ml), independent from cardiac function (EF, E/A and LVMI), and had good relations with eGFR (r=-0.3, p=0.001) and ACR (r=0.23, p=0.009). BNP had a significant positive correlation with carotid max IMT (r=0.34, p<0.001).
Conclusion: Our analysis revealed that BNP level reflects the degree of retention volume mainly depend on renal impairment. In cardiac function preserved CKD patients with HT, both BNP and PRA were up-regulated with retaining the counterbalance. These results suggest the level of BNP as a good marker of a salt-sensitivity, and a hyper salt-sensitivity facilitates arthrosclerosis in CKD patients.
- © 2012 by American Heart Association, Inc.