Background: The natriuretic peptides, Brain Natriuretic Peptide (BNP), C-type Natriuretic Peptide (CNP), are mediators of cardiovascular homeostasis. The impairment of arterial ability to vasodilate, also known as endothelial dysfunction, represents the first stage of atherosclerotic damage and may be assessed as brachial flow mediated vasodilation (FMV) in human. Generally an altered brachial FMV is documented in association to several cardiovascular risk factors as hypercholesterolemia. Aim of the study was to evaluate the behaviour of BNP and CNP in hyperlipemia and the potential relationship to FMV.
Patients and methods: Forty-four hyperlipemic patients (LDL-cholesterol > 130 mg/dl and/or triglycerides > 150, age 35-60 y) of both genders and 20 normolipemic patients, matched for age and sex were investigated.
Results: Patients had lower values of brachial FMV in comparison to controls (3.9 +/- 3.5 vs 7.5 +/- 0.5%, p < 0.005), no differences were observed in BNP (4.6 +/- 4.6 vs 5.9 +/- 3.4 ng/mL, p = n.s) and CNP (4.1 +/- 5.8 vs 5.7 +/- 3.3 ng/mL, p = n.s). Univariate analysis showed a positive correlation between BNP and HDL-cholesterol values (r = 0.36, p = 0.001). In the multivariate analysis, LDL-cholesterol (beta = -0.57), HDL-cholesterol (beta = 0.26) and brachial artery diameter (beta = -0.33) were predictors of brachial FMV. The only predictive variable for CNP was HDL-cholesterol (beta = 0.37).
Conclusions: The present study suggested that natriuretic peptides, BNP and CNP, are not altered in patients affected by hypercholesterolemia. Nevertheless, the levels of HDL-cholesterol are strictly related to the values of CNP. This observation, in humans, adds another mechanism to the vascular control exerted by HDL.