Role of dietary inflammatory index in the association of NT-proBNP with all-cause and cardiovascular mortality in NHANES 1999-2004.

N-terminal pro-Brain-type natriuretic peptide (NT-proBNP) has a predictive value of cardiovascular disease (CVD). Pro-inflammatory diet has been proven to be related to CVD. Our study investigated whether the association between NT-proBNP and mortality differed among general U.S. adults with different dietary inflammatory index (DII) scores. This study utilized the National Health and Nutrition Examination Surveys (NHANES) database from 1999 to 2004. Non-pregnant U.S. adults aged ≥ 20 years and without CVD were included. Cox regression model and restricted cubic splines were used to investigate the associations between NT-proBNP, DII, and mortality. A total of 9788 adults were included, and 2386 all-cause deaths with 668 CVD deaths occurred over 17.08 years of follow-up. NT-proBNP was positively associated with DII scores (P < 0.001). Among subjects without CVD, elevated NT-proBNP was positively associated with an increased risk of mortality, with per unit increase in log transformed NT-proBNP, the risk of all-cause and cardiovascular mortality increased by approximately 1.40 times (HR 2.397, 95%CI 1.966-2.922, P < 0.001) and 2.89 times (HR 3.889, 95%CI 2.756-5.490, P < 0.001) after adjusting for cardiovascular risk factors, similar results were observed after adjusting DII scores. Besides, significant interaction was found between lgNT-proBNP and DII on mortality (all P for interaction < 0.05). While as the DII quartiles increased, the association between lgNT-proBNP and mortality partially weakened. Our findings reveal that the association of NT-proBNP with all-cause and cardiovascular mortality differed with different DII scores among U.S. adults without CVD. A pro-inflammatory diet may partially explain the association between NT-proBNP and mortality and warrant further study.