Circadian Rhythm of Heart Rate, Urinary Cortisol Excretion, and Sleep in Civil Air Traffic Controllers

1. A heat-sink calorimeter, suitable for the measurement of energy expenditure in human subjects over periods up to 26 h, is described.2. The performance of the calorimeter is illustrated by a study of four normal subjects at rest or performing clerical work for a period of 7.5 h. Each condition was measured in duplicate in each subject. On the resting days the subjects were recumbent, and on the working days they were seated throughout the measurement period. Heart rate was monitored by infra-red telemetry and physical activity by an ultrasound movement detector. Urinary cortisol excretion was also measured as an indicator of stress.3. In each subject the mean heat loss on working days was higher than that on resting days: the increase ranged from 5.1 % to 16.7, with a mean value of 10.0% (P = 0.015). There was no significant difference between resting and working days in heart rate, physical activity or urinary cortisol excretion.4. The present study confirms that tiring clerical work has very little effect on 24 h energy expenditure.

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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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Relationship between heart rate and sinus arrhythmia in air traffic controllers at work

European Journal of Applied Physiology and Occupational Physiology ◽

10.1007/bf02332961 ◽

1981 ◽

Vol 47 (4) ◽

pp. 337-343 ◽

Cited By ~ 4

Author(s):

F. Lille ◽

Y. Burnod ◽

L. Borodulin

Keyword(s):

Heart Rate ◽

Air Traffic ◽

Sinus Arrhythmia ◽

Air Traffic Controllers

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Clinical evaluation of the liquid-chromatographic determination of urinary free cortisol.

Clinical Chemistry ◽

10.1093/clinchem/29.5.847 ◽

1983 ◽

Vol 29 (5) ◽

pp. 847-851 ◽

Cited By ~ 12

Author(s):

J Nakamura ◽

M Yakata

Keyword(s):

Normal Subjects ◽

Chromatographic Determination ◽

Urinary Free Cortisol ◽

Urinary Cortisol ◽

Liquid Chromatographic Method ◽

Free Cortisol ◽

Urinary Cortisol Excretion ◽

Liquid Chromatographic Determination ◽

Cortisol Excretion ◽

Liquid Chromatographic

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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