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Hyperandrogenism is a medical condition characterized by high levels of androgens.It is more common in women than men. [4] Symptoms of hyperandrogenism may include acne, seborrhea, hair loss on the scalp, increased body or facial hair, and infrequent or absent menstruation.
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ 4-dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA). It is closely related to androstenediol (androst-5-ene-3β,17β-diol).
Androgens increase in both males and females during puberty. [3] The major androgen in males is testosterone. [4] Dihydrotestosterone (DHT) and androstenedione are of equal importance in male development. [4] DHT in utero causes differentiation of the penis, scrotum and prostate.
Androstenedione is not bound to SHBG either, and is instead bound solely to albumin. [10] Estrone sulfate and estriol are also poorly bound by SHBG. [11] Less than 1% of progesterone is bound to SHBG. [12] SHBG levels are usually about twice as high in women as in men. [9] In women, SHBG serves to limit exposure to both androgens and estrogens. [9]
Androstanedione is formed from androstenedione by 5α-reductase and from DHT by 17β-hydroxysteroid dehydrogenase. [2] [3] It has some androgenic activity. [4] In female genital skin, the conversion of androstenedione into DHT through 5α-androstanedione appears to be more important than the direct conversion of testosterone into DHT. [5]
Female infants with classic CAH have ambiguous genitalia due to exposure to high concentrations of androgens in utero. [26] CAH due to 21-hydroxylase deficiency is the most common cause of ambiguous genitalia in genotypically normal female infants (46XX). Less severely affected females may present with early pubarche.
Plasma levels of DHEA in adult men are 10 to 25 nM, in premenopausal women are 5 to 30 nM, and in postmenopausal women are 2 to 20 nM. [25] Conversely, DHEA-S levels are an order of magnitude higher at 1–10 μM. [25] Levels of DHEA and DHEA-S decline to the lower nanomolar and micromolar ranges in men and women aged 60 to 80 years. [25]
According to a recent review, estrone levels have been elevated in 17 of 18 patients (94%), while estradiol levels have been elevated only in 13 of 27 patients (48%). [1] As such, estrone is the main estrogen elevated in the condition. [1] In more than half of patients, circulating androstenedione and testosterone levels are low to subnormal. [1]