Adrenal steroids in post-menopausal women: relation to obesity and to bone mineral content.

Basal levels and ACTH-induced increments of serum 17 alpha-hydroxyprogesterone (170HP), cortisol, 4-androstene-3,17-dione (A-4), dehydroepiandrosterone (DHA), and dehydroepiandrosterone sulphate (DHAS) were related to the degree of obesity and to trabecular bone mineral density in 29 postmenopausal women. The ACTH-induced increment of 170HP (delta 170HP) was negatively correlated to basal DHA and delta DHA. Positive correlations were found between obesity, expressed as Broca's index, and delta DHA and the delta DHA/delta 170HP ratio. Bone mineral density was positively correlated to basal DHAS, delta DHA, delta DHAS and the delta DHA/delta 170HP ratio, and negatively correlated to delta 170HP. DHA and 170HP represent a crossroad in adrenocortical steroid biosynthesis, leading to delta 5-androgens and glucocorticoids as main products. Besides age, obesity may also influence the intra-adrenal distribution between these two main steroidogenic pathways. The results suggest that differences at a very early stage of the adrenal steroidogenesis may influence calcium homeostasis in the post-menopausal woman.