Adrenal cortex function impairment in chronic fatigue syndrome

Abstract

Chronic fatigue syndrome (CFS) is defined as constellation of the prolonged fatigue and several somatic symptoms, in the absence of organic or severe psychiatric disease. However, this is an operational definition and conclusive biomedical explanation remains elusive. Similarities between the signs and symptoms of CFS and adrenal insufficiency prompted the research of the hypothalamo-pituitary-adrenal axis (HPA) derangement in the pathogenesis of the CFS. Early studies showed mild glucocorticoid deficiency, probably of central origin that was compensated by enhanced adrenal sensitivity to ACTH. Further studies showed reduced ACTH response to vasopressin infusion. The response to CRH was either blunted or unchanged. Cortisol response to insulin induced hypoglycaemia was same as in the control subjects while ACTH response was reported to be same or enhanced. However, results of direct stimulation of the adrenal cortex using ACTH were conflicting. Cortisol and DHEA responses were found to be the same or reduced compared to control subjects. Scott et al found that maximal cortisol increment from baseline is significantly lower in CFS subjects. The same group also found small adrenal glands in some CFS subjects. These varied and inconsistent results could be explained by the heterogeneous study population due to multifactorial causes of the disease and by methodological differences. The aim of our study was to assess cortisol response to low dose (1 microgram) ACTH using previously validated methodology. We compared cortisol response in the CFS subjects with the response in control and in subjects with suppressed HPA axis due to prolonged corticosteroid use. Cortisol responses were analysed in three subject groups: control (C), secondary adrenal insufficiency (AI), and in CFS. The C group consisted of 39 subjects, AI group of 22, and CFS group of nine subjects. Subject data are presented in table 1. Low dose ACTH test was started at 0800 h with the i.v. injection of 1 microgram ACTH (Galenika, Belgrade, Serbia). Blood samples for cortisol determination were taken from the i.v. cannula at 0, 15, 30, and 60 min. Data are presented as mean +/- standard error (SE). Statistical analysis was done using ANOVA with the Games-Howell post-hoc test to determine group differences. ACTH dose per kg or per square meter of body surface was not different between the groups. Baseline cortisol was not different between the groups. However, cortisol concentrations after 15 and 30 minutes were significantly higher in the C group than in the AI group. Cortisol concentration in the CFS group was not significantly different from any other group (Graph 1). Cortisol increment at 15 and 30 minutes from basal value was significantly higher in C group than in other two groups. However, there was no significant difference in cortisol increment between the AI and CFS groups at any time of the test. On the contrary, maximal cortisol increment was not different between CFS and other two groups, although it was significantly higher in C group than in...

Holistic Performance Institute Position Stand: Adrenal Fatigue

“…26 32 When CFS has been compared to diagnosed adrenal insufficiency (AI) and a control group (C) without CFS or AI it has been found that in some subjects cortisol response is preserved, while in others it is similar to one found in secondary adrenal insufficiency. 33 We believe that there are 'return to play / return to life' strategies that are evidence-based, for our clients presenting with fatigue, that do not rely on the diagnosis of a 'pseudocondition' that is yet to be described properly and using these strategies offers better potential for positive treatment outcomes.…”