Severe fatigue in patients with adrenal insufficiency: physical, psychosocial and endocrine determinants.

BACKGROUND: Fatigue is a frequently experienced complaint in patients with adrenal insufficiency (AI) and may be influenced by cortisol levels.

AIM: The objective of this study was to determine the prevalence of severe fatigue in adrenal insufficiency (AI) patients, to assess which dimensions contribute to fatigue severity and to determine the association between salivary cortisol levels and momentary fatigue.

SUBJECTS AND METHODS: We performed a cross-sectional study in the outpatient department of a university hospital. Included were 27 patients with congenital adrenal hyperplasia (CAH), 26 patients with primary AI (PAI), 24 patients with secondary AI (SAI) and 31 patients with adrenal insufficiency after treatment for Cushing's syndrome (Cush-AI). Measurements included computerised questionnaires to determine fatigue severity and physical and psychosocial contributors. Patients took four saliva samples at home, in which cortisol levels were measured.

RESULTS: Severe fatigue was experienced by 41 % of the CAH patients, 42 % of the PAI patients, 50 % of the SAI patients and 42 % of the Cush-AI patients. Psychological distress, functional impairment, sleep disturbance, physical activity, concentration problems and social functioning contributed to the subjective experience of fatigue. Salivary cortisol levels were not correlated with momentary fatigue.

CONCLUSIONS: A considerable proportion of AI patients experience severe fatigue. Salivary cortisol level is not a significant predictor for momentary fatigue in AI patients.