Evaluation of Chronic Uremia
Importance of Serum Urea Nitrogen, Serum Creatinine, and Their Ratio
- Joel D. Kopple, MD;
- Jack W. Coburn, MD
Abstract
In chronically uremic men receiving carefully controlled diets of varying protein intake during metabolic study, the ratio of serum urea nitrogen (SUN) to serum creatinine correlated closely with protein intake. This ratio was altered abruptly by even minor catabolic stresses or dehydration. The ratio of SUN to creatinine can be used to estimate the daily protein intake and can indicate the presence of unrecognized catabolic stress. Knowledge of its relation to protein intake can be used to determine the degree of protein restriction required to achieve a certain SUN level. In subjects undergoing periodic hemodialysis, SUN-serum creatinine ratios were lower, and the SUN level was a better indicator of dietary protein intake than the SUN-creatinine ratio.
Footnotes
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Reprint requests to VA Wadsworth Hospital Center, Wilshire and Sawtelle boulevards, Los Angeles 90073 (Dr. Kopple).
