Obesity and suppressed B-type natriuretic peptide levels in heart failure

OBJECTIVES This investigation evaluated the relationship between obesity and B-type natriuretic peptide (BNP) in heart failure. BACKGROUND Obesity is a major risk factor for the development of heart failure, but the precise mechanisms remain uncertain. Physiologically, natriuretic peptides and lipolysis are closely linked. METHODS A total of 318 patients with heart failure were evaluated between June 2001 and June 2002. Levels of BNP were compared in obese (body mass index [BMI] greater than or equal to30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) patients with respect to New York Heart Association functional class and lean body weight-adjusted peak aerobic oxygen consumption. In a subset of 36 patients, plasma levels of tumor necrosis factor-alpha, interleukin-6, and soluble intercellular adhesion molecule-1 were measured. RESULTS The population's BMI was 29.4 +/- 6.6 kg/m(2); 24% were lean (BMI <25 kg/m(2)), 31% overweight (BMI greater than or equal to25 to 29.9 kg/m(2)), and 45% obese (BMI greater than or equal to30 kg/m(2)). Obese patients were younger, more often African American, and more likely to have a history of antecedent hypertension, but less likely to have coronary artery disease and with only a trend toward diabetes mellitus. Levels of BNP were significantly lower in obese than in nonobese subjects (205 +/- 22 and 335 +/- 39 pg/ml, respectively; p = 0.0007), despite a similar severity of heart failure and cytokine levels. Multivariate regression analysis identified BMI as an independent negative correlate of BNP level. There were no differences in emergency department visits, heart failure hospitalization, or death between the obese and nonobese patients at 12-month follow-up. CONCLUSIONS Our investigation indicates that a state of reduced natriuretic peptide level exists in the obese individual with heart failure. (C) 2004 by the American College of Cardiology Foundation.