Background: Increased plasma amino-terminal-cleavage-fragment of NP (NT-proBNP) is an established indicator for heart failure. Moreover, obese adults had low circulating NT-proBNP suggesting an obesity-related dysregulation (natriuretic handicap). Secretion and/or clearance of NT-proBNP were discussed to be impaired in obesity. As only older adults were investigated so far, it remains unclear when during the evolution of obesity the state of a natriuretic handicap develops, and whether NT-proBNP may still serve as a relevant cardiac marker in obese juveniles.
Methods: We analysed NT-proBNP in juvenile (n=274, 10-18 years) and middle-aged (n=277, 18-50 years) normal weight (n=213) and obese (n=338) probands together with complex anthropometry, carotis sonography, clinical, and laboratory parameters.
Results: NT-proBNP showed a significant gender and age interaction. Adult females had significant higher NT-proBNP than adult males, and higher levels than juvenile females. Adult males had lower levels than juvenile males. Only a weak age and weight interaction was seen with obese juveniles which showed higher NT-proBNP than obese adults. Moreover, normal weight probands had higher NT-proBNP than overweight and obese. In a multiple regression including all probands, gender, creatinine and uric acid were the best predictors for NT-proBNP. In adults, female gender is the strongest driver for increased NT-proBNP.
Conclusions: These results argue against an essential influence of obesity to B-type cardiac natriuretic hormone system regulation in the absence of heart failure, and suggest NT-proBNP as a useful cardiac marker irrespective of age and obesity.