Background and Aim
B-type natriuretic peptides (BNP) is an emerging marker of cardiac distress in patients with volume overload. High BNP levels in hemodialysis (HD) patients are correlated with development of pathological cardiovascular findings, including left ventricular hypertrophy, hypertension and increased end-diastolic volume, and with increased cardiovascular and overall mortality. Intima-media thickness (IMT) is a marker of vascular dysfunction well correlated with the cardiovascular risk.
We supposed that BNP levels are dependent not only to the interdialytic weight variation (Δ) but also to the vascular dysfunction.
Aim: To determine the factors associated with high BNP in chronic HD patients.
Methods
Our chronic HD patients were enrolled. Hematological and biochemical variables were obtained by a pre-HD blood draw. We defined Pre-HD BNP>183 pg/mL as high BNP (were183 is the median of BNP in our population). Δ weight was defined as [(pre-HD weight -dry weight) / dry weight].
In all patients IMT of the common carotid artery was measured.
Student t-test and chi-square test were used in this analysis.
Results
A total of 74 chronic HD patients were enrolled. The age was 63 ± 13 years, males 54%, BNP 183 pg/mL (range IQ 91-499 pg/mL), IMT 1.76 ± 0.39 mm. Δ weight (1%, OR 1.28, 95% CI 1.01 – 1.63; P < 0.05), Systolic blood pressure (SBP) pre-HD (10mmHg, OR 1.28, 95%CI 1.01-1.61;P<0.05) and IMT (0.1mm, OR 1.22, 95% CI 1.05 – 1.43; P < 0.01) were associated with high BNP pre-HD (Model AUC = 0.73, P < 0.001).[Figura 1].
Conclusions
In chronic HD patients, BNP is influenced not only by the interdialytic weight variation, but also by the vascular function.