Dehydroepiandrosterone (DHEA), is a natural steroid hormone produced from cholesterol by the adrenal glands, the gonads, adipose tissue and the brain. DHEA is the precursor of, androstenedione, testosterone and estrogen. It is the most abundant hormone in the human body.
DHEA is produced from cholesterol through two cytochrome P450 enzymes. Cholesterol is converted to pregnenolone by the enzyme P450 scc (side chain cleavage) and then another enzyme CYP17A1 converts pregnenolone to 17?-Hydroxypregnenolone and then to DHEA. In humans DHEA is the dominant steroid hormone and precursor of all sex steroids. Humans produce DHEA in greater quantity than any other species. Even non-human primates have not much more than 10% the relative serum level of DHEA seen in humans. The fact that rodents produce so little DHEA makes the results of experiments conducted with these laboratory animals very controversial.
DHEA production is very high during fetal life by the fetal adrenal glands, declines after birth and remains low during childhood. Production begins around 6 years of age, increasing in quantity until peaking in early adulthood, around the age of 25, and declines afterwards to approximately 10% of peak levels by age 80. It is theorized by some that this decline may be due to reduced oxygen and glucose supply to the adrenal glands as a result of age-related atherosclerosis.
Role
In a simple view DHEA can be understood as a prohormone for the sex steroids. Its DHEAS variation may be looked at as buffer and reservoir. Its production in the brain suggests that is also has a role as a neurosteroid. As most DHEA is produced by the zona reticularis of the adrenal, it is argued that there is a role in the immune and stress response. DHEA may have more biologic roles.
As almost all DHEA is derived from the adrenal glands, blood measurements of DHEAS/DHEA are useful to detect excess adrenal activity as seen in adrenal cancer or hyperplasia, including certain forms of congenital adrenal hyperplasia. Women with polycystic ovary syndrome tend to have normal or mildly elevated levels of DHEAS.
Studies have shown that DHEA is useful in patients with systemic lupus erythematosus. An application of the evidence was reviewed by the FDA in 2001 and is available online. This review also shows that cholesterol and other serum lipids decrease with the use of DHEA.
Supplementation with DHEA has been shown to decrease insulin resistance.
Long term supplementation has been shown to improve mood and relieve depression
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