Impact of protein nutritional status on plasma BNP in elderly patients

BACKGROUND: Previous studies have demonstrated that the levels of B-type natriuretic peptide (BNP) in plasma are negatively correlated with Body Mass Index (BMI) whereas lean body mass is also closely related to plasma BNP. The purpose of this study is to determine the effect of protein nutritional status on plasma BNP in aged patients. METHODS AND RESULTS: The cross-sectional study was applied and the anthropometric measurement and nutritional biochemical test was performed in 1118 elderly inpatients in a stable condition were enrolled in the study (mean age, 75 years; 54% women). The partial correlation and multivariate regression analysis were conducted to analyze the relation of plasma BNP with covariates. After adjustment for confounding factors such as age, smoking and coexisting diseases, we found that the concentrations of BNP were independently associated with serum albumin (β=-0.065, P<0.001), serum total cholesterol (β=-0.097, P<0.012) and calf circumference (β=-0.032, P<0.014) in female patients, and associated with the serum albumin (β=-0.051, P<0.001), prealbumin (β=-2.177, P<0.026), mid-arm circumference (β=-0.062, P<0.001) and grip strength (β=-0.100, P<0.048) in male patients. Every 1 gram per liter of increased serum albumin corresponded to the reduced plasma BNP in male patients by 13.9% (OR 0.861, 95% CI 0.817, 0.909) and in female patients by 13.4% (OR 0.866, 95% CI 0.819, 0.916). CONCLUSIONS: Our study suggests that plasma BNP is negatively correlated with muscle mass, and it is also related to muscle force in male patients. The serum albumin is an independent determinant factor of BNP in both men and women. These findings suggest that good protein nutritional status could be beneficial in maintaining the cardiac function in elder population.