The effect of long-term glucocorticoid therapy on glucocorticoid receptor content and on steroid response to ACTH

The effect of long-term glucocorticoid therapy for systemic diseases on glucocorticoid receptor (GR) content and on basal and ACTH-stimulated levels of plasma and salivary cortisol 17 alpha-hydroxy-progesterone, androstenedione, 11 beta-hydroxyandrostenedione, DHEA, its sulfate and sex hormone-binding globulin (SHBG), as well as on basal levels of aldosterone, was investigated in a group of 24 children treated with prednisone for at least 8 months. The therapy was interrupted 24 h before the ACTH test and before plasma and saliva sampling. The control group consisted of 21 healthy children of corresponding age and sex. The patients were divided into two subgroups with normal and subnormal basal cortisolemia, they also differed in their response to ACTH. The GR levels in patient groups were indistinguishable from those found in controls. No correlation was found between GR content and basal levels of the above steroids or their response to ACTH. The best markers, apart from basal cortisolemia, for evaluation of the degree of suppression of adrenal function appeared to be the response of salivary (but not of plasma) cortisol and 17 alpha-hydroxy-progesterone to ACTH. Surprisingly, significantly lower levels of SHBG levels, which rose markedly after ACTH, were found in all the patients.