Hormonal responses to exercise in chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is a debilitating disease characterized by s evere, unexplained fatigue and post-exertional exacerbation of symptoms. We examined basal endocrine function in a group of CFS patients and a careful ly matched group of sedentary controls. The subjects then completed a grade d, maximal exercise test on a treadmill, and additional blood samples were drawn 4 min and a day after the end of exercise. There were no differences in basal hormone levels before exercise. Plasma adrenocorticotropin, epinep hrine, prolactin and thyrotropin responses 4 min after exercise were lower in the CFS group, but the growth hormone response may have been exaggerated , and the plasma norepinephrine response was similar to that in controls. T he next day, there were no differences in hormone levels between the groups , which suggests that long-term changes in endocrine function are unlikely to be a cause of the prolonged fatigue that occurs in CFS patients after a bout of exertion, Copyright (C) 2001 S. Karger AG. Basel.