Associations of N-terminal pro-B-type natriuretic peptide, estimated glomerular filtration rate, and mortality in US adults.

ABSTRACT

BACKGROUND: NT-proBNP is an important predictor of mortality but is inversely related to estimated glomerular filtration rate (eGFR). Whether the prognostic value of NT-proBNP is similar at different levels of kidney function is unknown. AIMS: We evaluated the association of NT-proBNP with eGFR and its implications for all-cause and cardiovascular mortality risk in the general population. METHODS: We included adults without prior cardiovascular disease from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2004. We used linear regression to characterize the cross-sectional associations of NT-proBNP with eGFR. We used Cox regression to assess the prospective associations of NT-proBNP with mortality across categories of eGFR. RESULTS: Among 11,456 participants (mean age 43 years, 48% female, 71% White, 11% Black), there was an inverse association between NT-proBNP and eGFR, which was stronger in those with more impaired kidney function. Per 15-unit decrease in eGFR, NT-proBNP was 4.3-fold higher for eGFR<30; 1.7-fold higher for eGFR 30 to 60, 1.4-fold higher for eGFR 61 to 90, 1.1-fold higher for eGFR 91 to 120 mL/min/1.73 m2. Over a median 17.6 years of follow-up, 2,275 deaths (622 cardiovascular) occurred. Higher NT-proBNP was associated with higher all-cause (HR per doubling of NT-proBNP 1.20, 95% CI 1.16-1.25) and cardiovascular mortality (HR 1.34, 95% CI 1.25-1.44). Associations were similar across eGFR categories (P-interaction >.10). Adults with NT-proBNP≥450 pg/mL and eGFR<60 mL/min/1.73m2 had 3.4-fold higher all-cause mortality and 5.5-fold higher cardiovascular mortality risk, compared to those with NT-proBNP<125 pg/mL and eGFR>90 mL/min/1.73m2. CONCLUSION: Despite its strong inverse association with eGFR, NT-proBNP has robust associations with mortality across the full range of kidney function in the general US adult population.