The role of hypocortisolism in chronic fatigue syndrome.

Abstract

BACKGROUND: There is accumulating evidence of hypothalamic-pituitary-adrenal (HPA) axis hypofunction in chronic fatigue syndrome (CFS). However, knowledge of  this hypofunction has so far come exclusively from research in adulthood, and its  clinical significance remains unclear. The objective of the current study was to  assess the role of the HPA-axis in adolescent CFS and recovery from adolescent  CFS. METHOD: Before treatment, we compared the salivary cortisol awakening  response of 108 diagnosed adolescent CFS patients with that of a reference group  of 38 healthy peers. Salivary cortisol awakening response was measured again  after 6 months of treatment in CFS patients. RESULTS: Pre-treatment salivary  cortisol levels were significantly lower in CFS-patients than in healthy  controls. After treatment recovered patients had a significant rise in salivary  cortisol output attaining normalization, whereas non-recovered patients improved  slightly, but not significantly. The hypocortisolism found in CFS-patients was  significantly correlated to the amount of sleep. Logistic regression analysis  showed that an increase of one standard deviation in the difference between pre-  and post-treatment salivary cortisol awakening response was associated with a 93%  higher odds of recovery (adjusted OR 1.93 (1.18 to 3.17), p=0.009). Pre-treatment  salivary cortisol did not predict recovery. CONCLUSIONS: Hypocortisolism is  associated with adolescent CFS. It is not pre-treatment cortisol but its change  to normalization that is associated with treatment success. We suggest that this  finding may have clinical implications regarding the adaptation of future  treatment strategies.