High Fluid Intake Increases Urine Free Cortisol Excretion in Normal Subjects—Authors’ Response

Abstract We recently reported (Clin. Chem. 28: 1497-1500, 1982) a liquid-chromatographic method for quantifying free cortisol in urine. We have since evaluated the clinical utility of our method by assaying cortisol in urine from normal subjects, patients, and subjects undergoing endocrine tests. We found that, in contrast with plasma cortisol, urinary cortisol is not bound to protein. It shows some correlation with 17-hydroxycorticosteroids in urine, but is independent of creatinine excretion. The amount of cortisol excreted daily by a particular individual was found to be fairly constant during nine or 10 days. Normal values determined for 203 apparently healthy individuals were 35.8 (SD 18.7) micrograms/day, with no significant sex-related differences but a tendency for a gradual decrease of cortisol excretion with age. We also report urinary cortisol excretion by patients with pituitary-adrenal disorders and some other diseases, and the pattern of response to dexamethasone and metyrapone administration.

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Response of normal subjects to prolonged high fluid intake

Journal of Applied Physiology ◽

10.1152/jappl.1964.19.1.134 ◽

1964 ◽

Vol 19 (1) ◽

pp. 134-136 ◽

Cited By ~ 14

Author(s):

Joel F. Habener ◽

Alfred M. Dashe ◽

David H. Solomon

Keyword(s):

Fluid Intake ◽

Daily Intake ◽

Normal Subjects ◽

Early Morning ◽

Solute Concentration ◽

Serum Osmolality ◽

Normal Individuals ◽

High Fluid ◽

Renal Concentrating Capacity ◽

Male Subjects

In order to test the hypothesis that the great variability seen in the serum osmolality characteristic of different normal persons is a result of fluid intake habits, four healthy male subjects ingested increasing amounts of fluid over a 4-week period reaching an average daily intake of approximately 8.5 liters during the 4th week. Serum osmolality measured repeatedly in the early morning and during weekly 6.5-hr water-deprivation tests did not vary significantly from that of control periods. It is concluded that in normal individuals fluid intake does not influence the “setting” of serum solute concentration. serum osmolality homeostasis; serum solute concentration in water loading; water intoxication; renal concentrating capacity; fluid balance; water regulatory mechanisms Submitted on June 25, 1963

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Urine-Free Cortisol Excretion: Evidence of Sex-Dependence

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456329403100505 ◽

1994 ◽

Vol 31 (5) ◽

pp. 455-458 ◽

Cited By ~ 26

Author(s):

Edmund J Lamb ◽

Khatoon A Noonan ◽

Jacky M Burrin

Keyword(s):

Urine Samples ◽

Healthy Individuals ◽

Urine Free Cortisol ◽

Free Cortisol ◽

Significant Difference ◽

Cortisol Excretion ◽

The Difference

Measurement of urine-free (unconjugated) cortisol (UFC) excretion is widely used in the investigation of hypercortisolaemia. We have measured 24 h UFC excretion in normal healthy individuals using a radioimmunoassay (RIA) method claimed to be suitable for unextracted urine. Significantly higher rates of excretion were found in a group of 15 men compared with a group of 18 women, with median values of 230 (range 145–334) and 149 (range 67–315) nmol/24 h, respectively ( P<0·005). This method was used to reanalyse the urine samples after extraction with dichloromethane. Although values were significantly lower than those found with unextracted urine ( P<0·001), the male : female difference remained with median values of 140 (range 96–295) and 112 (range 29–196) nmol/24 h, respectively ( P<0·02). Rates of UFC excretion were measured on the same dichloromethane-extracted urine samples using a second, different RIA, which again demonstrated the male : female difference with median values of 151 (range 116–302) and 109 (range 36–205) nmol/24 h, respectively ( P<0·001). There was no significant difference between these values and those obtained with extracted urine in the first assay. The higher rates of UFC excretion in men compared to women does not appear to be due to the presence of interfering compounds since the difference is also present using extracted urine samples and with two methods using different antibodies. These results should be borne in mind by laboratories when interpreting UFC results.

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Dose Distribution in Hydrocortisone Replacement Therapy Has a Significant Influence on Urine Free Cortisol Excretion

Experimental and Clinical Endocrinology & Diabetes ◽

10.1055/s-2003-44292 ◽

2003 ◽

Vol 111 (07) ◽

pp. 443-446 ◽

Cited By ~ 5

Author(s):

N. Bliesener ◽

S. Steckelbroeck ◽

L. Redel ◽

D. Klingmüller

Keyword(s):

Replacement Therapy ◽

Significant Influence ◽

Dose Distribution ◽

Urine Free Cortisol ◽

Free Cortisol ◽

Cortisol Excretion

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URINARY EXCRETION OF FREE CORTISOL IN HYPERCALCAEMIA

Acta Endocrinologica ◽

10.1530/acta.0.0740122 ◽

1973 ◽

Vol 74 (1) ◽

pp. 122-126 ◽

Cited By ~ 1

Author(s):

F. Schønau Jorgensen ◽

H. Kehlet

Keyword(s):

Urinary Excretion ◽

Hpa Axis ◽

Animal Studies ◽

Urinary Cortisol ◽

Free Cortisol ◽

Free Urinary Cortisol ◽

Urinary Cortisol Excretion ◽

Cortisol Excretion

ABSTRACT Human and animal studies have uniformly demonstrated increased hypothalamic-pituitary-adrenocortical (HPA) activity during acute hypercalcaemia. The HPA-activity during chronic hypercalcaemia was investigated by means of free urinary cortisol excretion. No difference in HPA activity could be demonstrated between a hyperparathyroid hypercalcaemic and a normocalcaemic group of patients. Based on these results it is suggested that during chronic hypercalcaemia, the HPA feed back mechanism overcomes the influence of hypercalcaemia on the HPA-axis.

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