Abstract
Many patients with fatigue are referred to psychosomatic medicine, but few studies have examined the hypothalamic-
pituitary-adrenal (HPA) axis in these patients. We conducted a corticotropin-releasing hormone (CRH) test on 86 patients with fatigue, no history of oral steroid use, and no pre-existing hypothalamic or pituitary disease. We confirmed non-oral steroid use and performed pituitary magnetic resonance imaging (MRI) in patients with peak cortisol
levels <18 μg/dL. The baseline cortisol level was 7.6±3.4 μg/dL, and the peak cortisol level in the CRH test was
15.4±3.6 μg/dL. Nineteen had a history of non-oral steroid use, and their peak cortisol levels were significantly lower
at 13.7±4.3 μg/dL (vs. 15.9±3.4 μg/dL in non-users; F=5.825, p=0.0179). Sixty-seven patients had peak cortisol levels <18 μg/dL, and 43 patients had levels <15.67 μg/dL. Fourteen patients were newly diagnosed with pituitary MRI
abnormalities, and their peak cortisol level was significantly lower than that of those without pituitary abnormalities
(12.4±4.1 μg/dL vs. 14.7±2.7 μg/dL; F=6.5130, p=0.0129). In conclusion, some patients with fatigue in psychosomatic medicine have a decreased HPA axis associated with non-oral steroid use or undetected pituitary abnormalities.
However, a significant number also exhibit a decreased HPA axis, despite having no history of non-oral steroid use
or pituitary abnormalities.
