Abstract
Theoretically urinary free corticosteroid excretion should be affected by renal function and this would make it a less sensitive index of hypercortisolaemia. In 28 consecutive urine samples there was a clear relationship (r = 0.83; P less than 0.001) over a range of creatinine clearances 0.3-200 ml/min. Although an allowance could be made for renal function this would not necessarily improve the discrimination of normal from abnormal. Until data comparing corrected to uncorrected urinary free corticosteroid excretion become available, we recommend a short dexamethasone test as the initial investigation in patients with suspected hypercortisolaemia and abnormal plasma creatinine concentrations.
Full text
PDF

Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Burke C. W., Beardwell C. G. Cushing's syndrome. An evaluation of the clinical usefulness of urinary free cortisol and other urinary steroid measurements in diagnosis. Q J Med. 1973 Jan;42(165):175–204. [PubMed] [Google Scholar]
- Hsu T. H., Bledsoe T. Measurement of urinary free corticoids by competitive protein-binding radioassay in hypoadrenal states. J Clin Endocrinol Metab. 1970 Apr;30(4):443–448. doi: 10.1210/jcem-30-4-443. [DOI] [PubMed] [Google Scholar]
- Sederberg-Olsen P., Binder C., Kehlet H. Urinary excretion of free cortisol in impaired renal function. Acta Endocrinol (Copenh) 1975 Jan;78(1):86–90. doi: 10.1530/acta.0.0780086. [DOI] [PubMed] [Google Scholar]
