Association Between Renal Function and Circulating Levels of Natriuretic Peptides (from the Dallas Heart Study)

The relations between renal function and circulating B-type natriuretic peptide (BNP) and the amino-terminal fragment of its prohormone (NT-pro-BNP) in the general population have not been fully elucidated. A total of 2,784 subjects from the Dallas Heart Study, a multiethnic population-based sample of Dallas County, Texas, residents, was studied. Detailed cardiac phenotyping, including magnetic resonance imaging and electron beam computed tomography, as well as measurements of NT-pro-BNP and BNP, were performed. Associations between estimated glomerular filtration rate (eGFR) and both NT-pro-BNP and BNP were evaluated using multivariable statistical analysis techniques. Median eGFR in this young, predominantly healthy population was 97 ml/min/1.73 m² (interquartile range 84 to 112). Natriuretic peptide levels were not associated with renal function over the normal range of eGFR. Below a threshold eGFR of 90 ml/min/1.73 m², both NT-pro-BNP and BNP increased in an exponential fashion with decreasing eGFR. These associations remained significant after adjustment for multiple potential confounders (p <0.001 for all). For eGFR <90 ml/min/1.73 m², the relative increase in NT-pro-BNP was twice as great as that for BNP for a given decrease in eGFR. In conclusion, a threshold effect regarding the association between renal function and natriuretic peptides was shown. With eGFR <90 ml/min/1.73 m², both NT-pro-BNP and BNP were inversely and independently associated with renal function, with a greater magnitude of association with renal impairment noted for NT-pro-BNP.