Background: Lower plasma B-type natriuretic peptide (BNP) concentrations in obese individuals ("natriuretic handicap") may play a role in the pathogenesis of obesity-related hypertension. Whether this phenomenon may contribute to hypertension in blacks is unknown. We tested the hypothesis that body mass index is inversely related to BNP concentrations in blacks.
Methods and results: We examined the relation of plasma BNP to body mass index in 3742 Jackson Heart Study participants (mean age, 55 ± 13; 62% women) without heart failure using multivariable linear and logistic regression, adjusting for clinical and echocardiographic covariates. The multivariable-adjusted mean BNP was higher for lean participants compared with obese participants in both normotensive (P<0.0001) and hypertensive (P<0.0012) groups. In sex-specific analyses, the adjusted mean BNP was higher in lean hypertensive individuals compared with obese hypertensive individuals for both men (20.5 versus 10.9 pg/mL, respectively; P=0.0009) and women (20.0 versus 13.8 pg/mL; P=0.011). The differences between lean and obese participants were more pronounced in normotensive participants (men, 9.0 versus 4.4 pg/mL; P<0.0001; women, 12.8 versus 8.4 pg/mL; P=0.0005). For both hypertensive and normotensive individuals in the pooled sample, multivariable-adjusted BNP was significantly related to both continuous body mass index (P<0.05 and P<0.0001, respectively) and categorical body mass index (P for trend <0.006 and <0.0001, respectively).
Conclusion: Our cross-sectional study of a large community-based sample of blacks demonstrates that higher body mass index is associated with lower circulating BNP concentrations, thereby extending the concept of a natriuretic handicap in obese individuals observed in non-Hispanic whites to this high-risk population.