 In one of our recent studies we investigated insulin sensitivity OGIS index and insulin secretion beta cell function with the insulinogenic index, IGI in patients with heart insufficiency by frequently sampled oral glucose tolerance test 21. Insulin sensitivity was impaired in CHF compared to control OGIS: 35414 mlminm2 vs. 45020; p0.003. Also beta cell function was reduced IGI: 10014 vs. 15045 pmolINSpmolGLUC. Interestingly a significant inverse correlation exists between BNP and IGI r0.41, p0.05 21. The relationship between BNP and glucose metabolism has only been partially investigated. Plasma BNP rises in response to hyperglycemia, but is not influenced by hyperinsulinemia 22, 23. On the other side, the physiological role of BNP on beta cell function and insulin sensitivity has not been investigated to date. As BNP levels rise with the degree of heart insufficiency and insulin resistance correlates to the degree of cardiomyopathy, we hypothesize that BNP influences glucose metabolism in healthy men. 