Variation in Urinary Creatinine Excretion and Its Relationship to Measurement of Urinary 17-Hydroxycorticosteroids.

摘要

Urinary creatinine excretion, measured in 96 24-h urine specimens collected from a single subject was less variable (CV, 9.3%) than daily urine volume (CV, 20.7%). However, a small variation in measured creatinine excretion did exist, since the observed CV of 9.3% was not explicable either on the basis of analytical error (CV for replicate determinations, 1.1%) or of collection error. Thus, 24-h urinary creatinine excretion is not constant. On the other hand, demonstrated variation in creatinine excretion was small, and urinary 17-hydroxycorticosteroids could be validly expressed in mg/g of creatinine. In a given individual, biologic variation in 24-h creatinine excretion is negligible as compared with variation in 17-hydroxycorticosteroid excretion. (Author)