Blood Urea Nitrogen (BUN) is a waste product produced by protein metabolism that is filtered out of the blood by the kidneys. High levels of BUN may indicate kidney disease or damage.

iollo markers that associate with Blood Urea Nitrogen


Arginine is another key amino acid in the urea cycle. Disruption of arginine metabolism in the urea cycle, such as in arginase deficiency, can result in high BUN levels.


Citrulline is an amino acid produced in the urea cycle that removes excess nitrogen. Impairment of the urea cycle can lead to elevated BUN levels. Citrulline levels may reflect urea cycle function and its effect on BUN.


Creatinine and BUN are both waste products filtered out of the blood by the kidneys. As kidney function declines, creatinine and BUN levels rise in tandem, making them key markers of kidney health and function.


Elevated homocysteine is associated with chronic kidney disease. Kidney dysfunction can impair homocysteine clearance while also raising BUN levels. The two markers may be correlated in kidney disease.


Ornithine is an amino acid produced from arginine in the urea cycle. Like citrulline and arginine, changes in ornithine may signify urea cycle issues contributing to increased BUN.

Symmetric dimethylarginine

SDMA is a methylated form of arginine that is elevated in chronic kidney disease. It likely reflects overall kidney function similar to BUN.