Abstract
Aim: The chronic fatigue syndrome is associated with alterations in the hypothalamus-pituitary-adrenal axis and cardiovascular autonomic nervous activity, suggesting a central dysregulation. This study explored differences among adolescent chronic fatigue syndrome patients and healthy controls regarding antidiuretic hormone, the renin-angiotensin-aldosterone-system, sex hormones and cardiac peptides.

Methods: We included a consecutive sample of 67 adolescents aged 12-18 years with chronic fatigue syndrome diagnosed according to a thorough and standardized set of investigations, and a volunteer sample of 55 healthy control subjects of equal gender and age distribution. Hormones were assayed with standard laboratory methods.

Results: Among patients, plasma antidiuretic hormone was significantly decreased and serum osmolality and plasma renin activity were significantly increased (p </= 0.001). Serum concentration of aldosterone, cortisol, NT-proBNP and sex hormones were not significantly different in the two groups.

Conclusion: Chronic fatigue syndrome in adolescents is associated with alterations in hormonal systems controlling osmolality and blood volume, possibly supporting a theory of central dysregulation.