Enhanced feedback sensitivity to prednisolone in chronic fatigue syndrome.

Objective: Enhancement of negative feedback control of the HPA axis in patients with chronic fatigue syndrome (CFS) has been reported using the low dose dexamethasone suppression test. We have developed the use of prednisolone (5mg) as a more physiologically appropriate alternative to dexamethasone in the investigation of mild degrees of glucocorticoid resistance or supersensitivity. The objective of the study was to use this test to look for alterations in negative feedback control of the HPA axis in CFS patients.

Urinary cortisol and cortisol metabolite excretion in chronic fatigue syndrome.

Objectives: Reduced basal hypothalamic-pituitary-adrenal (HPA) axis output in chronic fatigue syndrome (CFS) has been inferred from low cortisol levels in blood, saliva, and urine in some studies. Because > 95% of cortisol is metabolized before excretion, we assessed cortisol output by assay of both cortisol metabolites and free cortisol in 24-hour urine collections and also investigated sex differences in these between CFS and control groups.

Method: We calculated total urinary cortisol metabolites (TCM) and cortisol metabolite ratios from individual steroid data in 40 patients (20 males and 20 females) with CFS who were free of medication or comorbid psychiatric disorder likely to influence the HPA axis.

Circadian rhythm of urinary steroid metabolites.

Background: Samples submitted for urinary steroid profile analysis are often untimed, but influence of collection time on interpretation is unknown. We report circadian rhythms of the major steroid metabolites and derived ratios in urine collected at 3-h intervals over 24 h, after first establishing that disturbance of sleep associated with collection does not alter rhythms on the succeeding day.

Methods: Assay of steroid metabolites (gas chromatography) and creatinine in urine collections made by 10 men and 10 women every 3 h starting at 2,100 for 24 h.

Diurnal excretion of urinary cortisol, cortisone, and cortisol metabolites in chronic fatigue syndrome.

Objective: The aim of this study was to obtain comprehensive information on basal hypothalamic-pituitary-adrenal (HPA) axis activity in chronic fatigue syndrome (CFS) patients who were not affected by medication or comorbid psychiatric disorder likely to influence the HPA axis.

Method: Steroid analysis of urine collections from 0600 to 2100 h at 3-h intervals in CFS patients and in controls.

Results: Urinary free cortisol and cortisone concentrations showed a significant normal diurnal rhythm, but levels were lower across the cycle in CFS.

Midazolam in the reduction of surgical stress: a randomized clinical trial.

Objective: The objective of this study was to assess the role of midazolam in reducing surgical stress as measured using subjective and objective variables.

Study Design: The study was a double-blind randomized controlled trial. Thirty-eight male patients undergoing surgical removal of third molars under general anesthesia were recruited for this study, each patient was given premedication (midazolam or placebo) and subjective variables (HAD scale) were obtained and objective variables (salivary cortisol samples and vital signs) were collected pre-, peri-, and postoperatively.

Assessment of subtle changes in glucocorticoid negative feedback using prednisolone: comparison of salivary free cortisol and urinary cortisol metabolites as endpoints.

Background: Prednisolone is better than dexamethasone to probe subtle changes in HPA axis sensitivity but cortisol assay as an endpoint risks cross-reaction with prednisolone. We compared capillary gas chromatography, which distinguishes urinary cortisol and prednisolone metabolites, and salivary cortisol immunoassay.

Methods: Twenty adult volunteers (10 m) collected urine for consecutive 3 h periods and saliva at 3 h intervals from 2100 for 24 h, took prednisolone (5 mg) at midnight and continued collecting until 2100.