CNP and endothelial dysfunction: Our major findings are as following: (1) Increased plasma CNP was associated with reduced HRV; (2) Decreased renal function was not associated with elevated plasma CNP level; (3) Circulating CNP was not reduced in patients with endothelial dysfunction compared to those with preserved endothelial function; (4) There was no association between plasma CNP and blood pressure or arterial elasticity (neither central or peripheral).