[Hormones and osteoporosis update. Adrenal androgen and bone].

DHEA is the major source for estrogen biosynthesis in postmenopausal women, since DHEA is converted to estrogen by aromatase in peripheral tissues. It has been suggested by animal models that a direct action of DHEA on bone tissue exists in addition to a biological action by estradiol converted from DHEA. Several RCTs (randomized, double-blinded, controlled trials) indicated that administration of daily 50 mg of DHEA increased bone mineral density (BMD) of lumbar spine or femoral neck. Increment of BMD was significant but small. The effect of DHEA on BMD is considered to be attributable to that of estradiol converted from DHEA, judging from analysis of serum steroid hormone concentrations.