Relation of B-type natriuretic peptide levels to body mass index after comprehensive lifestyle changes.

Cross-sectional studies have reported inverse associations of B-type natriuretic peptide (BNP) with the body mass index (BMI). We evaluated whether changes in the BMI are associated with changes in BNP. A nested prospective cohort study of a lifestyle intervention (low-fat, whole-foods diet, exercise, stress management, and social support) was conducted. BNP, BMI, and other biomarkers were measured at baseline and 3 months. A total of 131 subjects, 56 with coronary heart disease (CHD) and 75 at high risk, with > or =3 CHD risk factors and/or diabetes mellitus, were enrolled. At 3 months, the mean BMI had decreased (34.4 to 31.7 kg/m(2), p <0.001), BNP had increased (median 18 to 28 pg/ml, p <0.001), and low-density lipoprotein, C-reactive protein, apolipoprotein B (all p <0.002), and angina frequency (p = 0.017) and severity (p = 0.052) had decreased. The subjects' physical limitations had decreased and their physical functioning had improved (all p <0.001). The percentage of change in BNP was inversely associated with the percentage of change in insulin (r = -0.339, p = 0.005, n = 63 nondiabetics). It was also inversely associated with the percentage of change in BMI (r = -0.28, p = 0.002, n = 116), and this association remained significant (p = 0.029) in multiple regression analyses controlling for age, gender, CHD, diabetes mellitus, percentage of change in lifestyle index, and beta-blocker use. The metabolic changes related to adipose tissue lipolysis could explain these findings. In conclusion, BNP increased in subjects experiencing weight loss while following a lifestyle intervention, and angina pectoris, physical limitations, and other CHD risk factors decreased. Therefore, in this context, increasing BNP might not indicate worsening disease or a worsening prognosis. Thus, the proposed use of BNP in monitoring disease progression should take into account changes in the BMI during the same period. Copyright 2010 Elsevier Inc. All rights reserved.