Determinants of low levels of brain natriuretic peptide in morbid obesity.

BACKGROUND & AIMS: morbid obesity is associated with cardiovascular comorbidity. A noteworthy feature of this relationship could regard low levels of brain natriuretic peptide (BNP). The study investigates the relationship between BNP and obesity-related markers in a morbid obese population, along with echocardiographic and vascular parameters.

METHODS

in 154 morbid obese patients we evaluated anthropometric parameters, glycometabolic/lipid profile, bioimpedentiometry, echocardiography, visceral fat area and flow-mediated dilation (FMD) by ultrasonography.

RESULTS

we divided population in two groups on the basis of median BMI levels; patients with higher BMI had significantly lower BNP (p = .008), FMD (p = .014) and HDL-C (p = .001) and showed a more impaired heart function. A similar trend emerged subdividing patients on the basis of median visceral fat area. BNP showed a significant inverse correlation with BMI (p < .001), left ventricular mass (p = .026) and inter-ventricular septum thickness (p = .007) and a significant positive correlation with FMD (p = .008), HDL-C (p = .022), and ejection fraction (p = .013). BMI and triglycerides were independent predictors of BNP levels.

CONCLUSIONS

patients with higher BMI show lower BNP levels associated with greater total body fat amount. The correlation of BNP with endothelium-dependent vasodilation and cardiac impairment could represent another link between obesity and cardiovascular damage.