Circadian rhythms in plasma cortisone and cortisol and the cortisone/cortisol ratio
Nomura, S.; Fujitaka, M.; Sakura, N.; Ueda, K.
Clinica Chimica Acta; International Journal of Clinical Chemistry 266(2): 83-91
ISSN/ISBN: 0009-8981 PMID: 9437537 DOI: 10.1016/s0009-8981(97)00142-3
We evaluated the circadian rhythms in the plasma concentrations of cortisol, cortisone and their free forms, and in the cortisone/cortisol ratios by means of reversed-phase high performance liquid chromatography in normal adult subjects. Plasma concentrations of cortisone, as well as cortisol, exhibited a circadian rhythm. The ratios of cortisone/cortisol remained almost constant during the waking hours of normal subjects. Changes in the cortisone/cortisol ratios previously reported in patients with various diseases exceeded the diurnal changes detected in the present study. Thus, the determination of the cortisone/cortisol ratio provides information that is useful in assessing the adrenal function of patients with various diseases.