Abstract 2555: Obesity Should Be Considered Into The Inter-Individual Variability Of Plasma BNP Levels In The Diagnosis And Management Of Heart Failure
Background Suppressed BNP levels have been reported in obese individuals with heart failure (HF). However, hemodynamic factors, which mainly regulate BNP secretion, were not adequately considered in the analysis. Recently, we reported a close association between BNP levels and LV end-diastolic wall stress (EDWS) as the underlying mechanism of BNP secretion. Therefore, we investigated the relationship between body mass index (BMI) and plasma BNP levels in HF based on the BNP - EDWS relationship.
Methods In 240 consecutive patients who presented with HF, we measured plasma BNP levels and performed echocardiography and cardiac catheterization. Meridional EDWS was calculated from echocardiographic and hemo-dynamic parameters.
Results The BMI for the total population was 22.9 ± 0.2 kg/m2; 21% were lean (BMI < 20) and 27% obese (BMI > 25). Obese patients were more likely to have a history of hypertension and diabetes mellitus, with a trend toward hyperlipidemia. The correlation between plasma BNP and EDWS [r = 0.771 (p<0.001)] was more robust than any other parameter. By a univariate analysis, BMI was inversely correlated with both BNP levels and EDWS (p<0.001 in both). However, a multivariate regression analysis that took into account EDWS demonstrated a significant association between BMI and BNP (β coefficient = −0.043, p<0.001).
Conclusion The present study shows that BMI determines the BNP level in a manner that is independent of the hemodynamic load in patients with HF. These findings suggest that obesity should be considered to be associated with the inter-individual variability of plasma BNP levels in the diagnosis and management of HF.