Dehydroepiandrosterone (DHEA) is a steroid hormone produced predominantly by the adrenal glands, which are situated just above the kidneys. It is one of the most abundant circulating hormones in the human body, but it is not highly active on its own. DHEA functions mainly as a precursor that the body utilizes to synthesize other, more potent hormones. Understanding what constitutes a “normal” level of DHEA is complex because concentrations change dramatically over a person’s lifetime, requiring interpretation within a specific age and sex context.
The Biological Role of DHEA
DHEA functions as a prohormone, serving as the biochemical starting point for sex hormone production. It is converted in peripheral tissues into androgens, such as testosterone, and estrogens, such as estradiol. This conversion allows the body to regulate hormone levels locally where they are needed.
DHEA and its sulfated form, DHEA-S, also have independent actions within the body. These hormones act as neurosteroids, influencing brain function, mood, and cognitive processes. They also play a part in modulating the immune system and influencing metabolic functions.
The Lifetime Curve of DHEA Production
DHEA production follows a predictable pattern across the human lifespan. Levels are initially high during fetal development, where DHEA serves as a substrate for placental estrogen synthesis. Following birth, concentrations drop sharply and remain minimal throughout early childhood.
A significant increase in DHEA and DHEA-S begins between ages six and eight in a process called adrenarche. This rise is independent of sexual puberty and is responsible for the development of pubic hair, axillary hair, and adult body odor. DHEA concentrations continue to climb throughout adolescence, reaching their peak in the second or third decade of life, typically around the mid-twenties to age 30.
Following this peak, DHEA levels begin a slow, linear decline that continues for the rest of life, a phenomenon sometimes referred to as adrenopause. By the time a person reaches 80 years of age, their DHEA-S concentration may be only about 10% to 20% of the maximum level they had in early adulthood.
Establishing Normal Reference Ranges and Measurement
The reference range for DHEA is highly specific to age, sex, and the testing methodology used by the laboratory. Laboratories publish stratified ranges that reflect the expected variation for a given demographic. For instance, DHEA-S levels in a healthy 25-year-old male are substantially higher than those in a 75-year-old female.
Clinicians typically measure the sulfated form of the hormone, DHEA-S. DHEA-S is preferred because it is far more stable in the bloodstream, lacking the rapid fluctuations and circadian rhythm seen with unconjugated DHEA. This makes it a reliable marker for the average adrenal gland production.
A young adult male in his 20s can have DHEA-S levels ranging from approximately 280 to 640 micrograms per deciliter (\(\mu\)g/dL), while a female in the same age group might range from 65 to 380 \(\mu\)g/dL. By age 70 and above, the normal range for men drops to around 28 to 175 \(\mu\)g/dL, and for women, it may fall to 17 to 90 \(\mu\)g/dL. These wide ranges underscore why results must always be compared against the lab’s specific age and sex reference data.
Testing is usually performed using a blood serum sample, although other methods like saliva testing exist. The technique used to analyze the sample, such as liquid chromatography-mass spectrometry (LC-MS), can also influence the reported reference values. Interpreting a DHEA-S result requires careful consideration of the patient’s biological context and the laboratory’s established standards.
Clinical Significance of Deviations in DHEA Levels
DHEA-S testing is often used to investigate conditions related to adrenal gland function or excess androgen production. When DHEA-S levels are found to be significantly above the established age- and sex-specific reference range, it can indicate a potential underlying health issue. High concentrations are commonly seen in women with Polycystic Ovary Syndrome (PCOS), a hormonal disorder characterized by elevated androgens.
Abnormally high DHEA-S can also be a sign of adrenal disorders, such as congenital adrenal hyperplasia or the presence of an adrenal tumor. In children, elevated levels can lead to the premature onset of secondary sexual characteristics, known as precocious puberty. These high levels prompt further testing to identify the source of the excess hormone production.
Conversely, DHEA-S levels that are significantly below the expected range can also point to a medical problem. Low concentrations are often observed in cases of adrenal insufficiency, a condition where the adrenal glands do not produce enough hormones. This includes Addison’s disease, an autoimmune disorder that damages the adrenal cortex. Low levels may also be seen in individuals experiencing severe systemic illness or prolonged chronic stress.