Impact of Body Mass Index on Plasma N-Terminal ProB-Type Natriuretic Peptides in Chinese Atrial Fibrillation Patients without Heart Failure

BACKGROUND: An inverse relationship between body mass index (BMI) and circulating levels of N-terminal proB-type natriuretic peptide (NT-proBNP) has been demonstrated in subjects with and without heart failure. Obesity also has been linked with increased incidence of atrial fibrillation (AF), but its influence on NT-proBNP concentrations in AF patients remains unclear. This study aimed to investigate the effect of BMI on NT-proBNP levels in AF patients without heart failure. METHODS: A total of 239 consecutive patients with AF undergoing catheter ablation were evaluated. Levels of NT-proBNP and clinical characteristics were compared in overweight or obese (BMI≥25 kg/m(2)) and normal weight (BMI<25 kg/m(2)) patients. RESULTS: Of 239 patients, 129 (54%) were overweight or obese. Overweight or obese patients were younger, more likely to have a history of nonparoxysmal AF, hypertension, and diabetes mellitus. Levels of NT-proBNP were significantly lower in overweight or obese than in normal weight subjects (P<0.05). The relationship of obesity and decreased NT-proBNP levels persisted in subgroup of hypertension, both gender and both age levels (≥65 yrs and <65 yrs).Multivariate linear regression identified BMI as an independent negative correlate of LogNT-proBNP level. CONCLUSIONS: An inverse relationship between BMI and plasma NT-proBNP concentrations have been demonstrated in AF patients without heart failure. Overweight or obese patients with AF appear to have lower NT-proBNP levels than normal weight patients.