In order to determine the amount of uropepsin excreted every 24 hours by normal individuals as well as by those with diagnosed disorders, 960 uropepsin determinations were performed on 280 patients. There is a significant fluctuation in daily excretion by the same individual and a marked degree of overlapping of results between normal individuals and patients with duodenal and gastrointestinal lesions. Both physical and emotional stress may have an effect on uropepsin excretion. It is felt that these variables make the uropepsin excretion an unreliable test in routine gastrointestinal diagnosis.
Corazza LJ, Myerson RM. THE INFLUENCE OF VARIOUS CLINICAL DISORDERS AND DRUGS ON EXCRETION OF UROPEPSIN. JAMA. 1957;165(2):146-149. doi:10.1001/jama.1957.02980200026008