or a not-so-worrisome creatinine, in a person who’s 80 years old may reflect a lower GFR.” Blood urea nitrogen, or BUN, measures the amount of urea nitrogen, a waste product of protein ...

[7] The normal ratio of BUN to creatinine is 10:1 ... substantially lower than the gentleman, and signifies poor creatinine clearance. Even though she may not show signs of renal compromise ...