90 - Adrenal Androgens, Adrenarche, and Adrenopause

Abstract

The adrenal glands consist of the cortex and medulla, which have distinct embryonic origins and functions. Adrenarche is defined as the increased dehydroepiandrosterone sulfate (DHEAS) secretion by the zona reticularis that occurs between 6 and 8 years of age. The factors responsible for the onset of adrenarche remain unclear. Pubarche, characterized by the development of pubic hair, is the clinical manifestation of adrenarche and is arbitrarily defined as premature if pubic hair develops prior to age 8 years in girls and 9 years in boys. Premature adrenarche is a diagnosis of exclusion. Adrenopause is characterized by the decline in dehydroepiandrosterone (DHEA) and DHEAS levels later in life. DHEA has been suggested as a supplemental treatment for women undergoing in vitro fertilization. Lower DHEAS concentrations are associated with increased risk for cardiovascular disease. However, whether DHEAS has a specific role or is merely a bystander for cardiovascular disease remains to be determined. Brain concentrations of DHEA and DHEAS are higher than those in the peripheral circulation; DHEA and DHEAS can be synthesized in the brain. The observation of declining DHEA/DHEAS concentrations with aging led to clinical trials involving DHEA supplementation. To date, evidence that DHEA benefits body composition, cognition, mood, or sexual function in older men remains inconsistent. Despite being the most abundant circulating steroid hormones in the circulation, the precise physiologic actions and regulatory mechanisms for DHEA and DHEAS remain mysteries to be solved.