hypogonadism


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Related to hypogonadism: hypogonadotropic hypogonadism, secondary hypogonadism

Hypogonadism

 

Definition

Hypogonadism is the condition more prevalent in males in which the production of sex hormones and germ cells are inadequate.

Description

Gonads are the organs of sexual differentiation—in the female, they are ovaries; in the male, the testes. Along with producing eggs and sperm, they produce sex hormones that generate all the differences between men and women. If they produce too little sex hormone, then either the growth of the sexual organs or their function is impaired.
The gonads are not independent in their function, however. They are closely controlled by the pituitary gland. The pituitary hormones are the same for males and females, but the gonadal hormones are different. Men produce mostly androgens, and women produce mostly estrogens. These two hormones regulate the development of the embryo, determining whether it is a male or a female. They also direct the adolescent maturation of sex organs into their adult form. Further, they sustain those organs and their function throughout the reproductive years. The effects of estrogen reach beyond that to sustain bone strength and protect the cardiovascular system from degenerative disease.
Hormones can be inadequate during or after each stage of development—embryonic and adolescent. During each stage, inadequate hormone stimulation will prevent normal development. After each stage, a decrease in hormone stimulation will result in failed function and perhaps some shrinkage. The organs affected principally by sex hormones are the male and female genitals, both internal and external, and the female breasts. Body hair, fat deposition, bone and muscle growth, and some brain functions are also influenced.

Causes and symptoms

Sex is determined at the moment of conception by sex chromosomes. Females have two X chromosomes, while males have one X and one Y chromosome. If the male sperm with the Y chromosome fertilizes an egg, the baby will be male. This is true throughout the animal kingdom. Genetic defects sometimes result in changes in the chromosomes. If sex chromosomes are involved, there is a change in the development of sexual characteristics.
Female is the default sex of the embryo, so most of the sex organ deficits at birth occur in boys. Some, but not all, are due to inadequate androgen stimulation. The penis may be small, the testicles undescended (cryptorchidism) or various degrees of "feminization" of the genitals may be present.
After birth, sexual development does not occur until puberty. Hypogonadism most often shows up as an abnormality in boys during puberty. Again, not every defect is due to inadequate hormones. Some are due to too much of the wrong ones. Kallmann's syndrome is a birth defect in the brain that prevents release of hormones and appears as failure of male puberty. Some boys have adequate amounts of androgen in their system but fail to respond to them, a condition known as androgen resistance.
Female problems in puberty are not caused by too little estrogen. Even female reproductive problems are rarely related to a simple lack of hormones, but rather to complex cycling rhythms gone wrong. All the problems with too little hormone happen during menopause, which is a normal hypogonadism.
A number of adverse events can damage the gonads and result in decreased hormone levels. The childhood disease mumps, if acquired after puberty, can infect and destroy the testicles—a disease called viral orchitis. Ionizing radiation and chemotherapy, trauma, several drugs (spironolactone, a diuretic and ketoconazole, an antifungal agent), alcohol, marijuana, heroin, methadone, and environmental toxins can all damage testicles and decrease their hormone production. Severe diseases in the liver or kidneys, certain infections, sickle cell anemia, and some cancers also affect gonads. To treat some male cancers, it is necessary to remove the testicles, thereby preventing the androgens from stimulating cancer growth. This procedure, still called castration or orchiectomy, removes androgen stimulation from the whole body.
For several reasons the pituitary can fail. It happens rarely after pregnancy. It used to be removed to treat advanced breast or prostate cancer. Sometimes the pituitary develops a tumor that destroys it. Failure of the pituitary is called hypopituitarism and, of course, leaves the gonads with no stimulation to produce hormones.

Key terms

Biopsy — Surgical removal of pieces of tissue for examination.
Embryo — Refers to life before birth, specifically the first two months after conception.
Fetus — The unborn person or animal, still in the womb.
Hypothalamus — Part of the brain just above the pituitary that stimulates pituitary gland function.
Ionizing radiation — X rays. Diagnostic x rays are too weak to do damage under normal circumstances, but x rays used to treat cancer must be used with great care.
Undescended testicle — A testicle that is still in the groin and has not made its way into the scrotum.
Besides the tissue changes generated by hormone stimulation, the only other symptoms relate to sexual desire and function. Libido is enhanced by testosterone, and male sexual performance requires androgens. The role of female hormones in female sexual activity is less clear, although hormones strengthen tissues and promote healthy secretions, facilitating sexual activity.

Diagnosis

Presently, there are accurate blood tests for most of the hormones in the body, including those from the pituitary and even some from the hypothalamus. Chromosomes can be analyzed, and gonads can, but rarely are, biopsied.

Treatment

Replacement of missing body chemicals is much easier than suppressing excesses. Estrogen replacement is recommended for nearly all women after menopause for its many beneficial effects. Estrogen can be taken by mouth, injection, or skin patch. It is strongly recommended that the other female hormone, progesterone, be taken as well, because it prevents overgrowth of uterine lining and uterine cancer. Testosterone replacement is available for males who are deficient.

Resources

Books

Carr, Bruce R., and Karen D. Bradshaw. "Disorders of the Ovary and Female Reproductive Tract." In Harrison's Principles of Internal Medicine, edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1998.

hypogonadism

 [hi″po-go´nad-izm]
decreased functional activity of the gonads, with retardation of growth, sexual development, and secondary sex characters. The American Association of Clinical Endocrinologists has published “Clinical Practice Guidelines for the Evaluation and Treatment of Hypogonadism in Adult Male Patients.” These are available online at their web site: http://www.aace.com.
hypergonadotropic hypogonadism that associated with secretion of high levels of gonadotropins, as in Klinefelter's syndrome. Called also hypergonadotropic eunuchoidism.
hypogonadotropic hypogonadism that due to lack of gonads or of gonadotropin secretion. Called also hypogonadotropic eunuchoidism.

hy·po·go·nad·ism

(hī'pō-gō'nad-izm),
Inadequate gonadal function, as manifested by deficiencies in gametogenesis or the secretion of gonadal hormones; results in atrophy or deficient development of secondary sexual characteristics and, when occurring in prepubertal males, in altered body habitus, characterized by a short trunk and long limbs.

hypogonadism

/hy·po·go·nad·ism/ (-go´nad-izm) decreased functional activity of the gonads, with retardation of growth, sexual development, and secondary sex characters.
hypergonadotropic hypogonadism  that associated with high levels of gonadotropins, as in Klinefelter's syndrome.
hypogonadotropic hypogonadism  that due to lack of gonadotropin secretion.

hypogonadism

(hī′pō-gō′năd-ĭz′əm, -gŏn′ə-dĭz′əm)
n.
Inadequate functioning of the testes or ovaries as manifested by deficiencies in gametogenesis or the secretion of gonadal hormones.

hypogonadism

[-gō′nədiz′əm]
a deficiency in the secretory activity of the ovary or testis. The condition may be primary or caused by a gonadal dysfunction involving the Leydig's cells in the male, or it may be secondary to a hypothalamus or pituitary disorder. Secondary hypogonadism is sometimes further differentiated into pituitary hypogonadism and hypothalamic hypogonadism.

hypogonadism

Endocrinology
1. Inadequate gonadal function, as manifest by defects in gametogenesis, secretion of, and/or response to, gonadal hormones. Cf Androgen replacement therapy.
2. A clinical condition with ↓ or absent phenotypic expression of a person's sexual genotype, which may be 1º, due to a lack of end organ response to FSH or LH produced normally by an intact pituitary gland–hypergonadotropic hypogonadism, or 2º to defective hypothalamic or pituitary hormonal activity–hypogonadotropic hypogonadism
Hypogonadism, etiology
Primary
Hypergonadotropic Turner syndrome, XX Turner sydrome, XX pure gonadal dysgenesis, mixed gonadal dysgenesis, autoimmune ovarian disease
Hypergonadotropic Congenital anorchia, rudimentary testes, germ cell hypoplasia–del Castillo syndrome, XY Turner phenotype–Noonan syndrome, Klinefelter syndrome and variants, XX males, XYY males
Secondary
Hypogonadotropic Carpenter syndrome, hypopituitarism, Lawrence-Moon-Biedl, multiple lentigines syndrome, polycystic ovaries
Hypogonadotropic Amyloidosis, Carpenter syndome, fertile eunuch syndrome, Fröhlich syndrome, Sheehan syndrome, Kallmann's disease, Laurence-Moon-Biedl disease, Lowe syndrome, Prader-Willi syndrome  
.

hy·po·go·nad·ism

(hī'pō-gō'nad-izm)
Inadequate gonadal function, as manifested by deficiencies in gametogenesis or the secretion of gonadal hormones.

hypogonadism

Failure of the normal production, by the testicles or ovaries, of sex hormones, or failure of production of sperms (spermatozoa) or eggs (ova). Female hypogonadism occurs after the menopause. Male hypogonadism, as from testicular injury, mumps, testicular torsion, bilateral orchiectomy or other causes may lead to osteoporosis

hy·po·go·nad·ism

(hī'pō-gō'nad-izm)
Inadequate gonadal function, as manifested by deficiencies in gametogenesis or secretion of gonadal hormones.

hypogonadism (hī´pōgō´nad-izəm),

n a gonadal deficiency resulting from abnormalities of the testes and ovaries or to pituitary insufficiency. Manifestations include eunuchism, eunuchoidism, Frohlich's syndrome, amenorrhea, and incomplete development or maintenance of secondary sex characteristics.

hypogonadism

decreased functional activity of the gonads, with reduced production of germ cells and/or hormones; may be associated with retardation of growth and sexual development.
References in periodicals archive ?
The American Urological Association has echoed several recommendations from AACE, emphasizing in its own statement that "testosterone therapy in the absence of hypogonadism is inappropriate" and calling for more federal and industry funding for studies of the indications, benefits, and risks of approved treatments for hypogonadism as well as studies of new potential therapies.
Currently, one of the most popular methods for hypogonadism screening is the use of questionnaires, such as The Saint Louis University Androgen Deficiency in the Aging Male (ADAM) questionnaire, (7) The Aging Male's Symptoms (AMS) rating scale, (8) the Massachusetts Male Aging Study (MMAS) questionnaire, (9) and the New England Research Institutes (NERI) hypogonadism questionnaire.
The diagnostic approach to hypogonadism is illustrated in Figure 1.
Male hypogonadism is most commonly diagnosed through a simple blood test.
With other assays, hCG >5 IU/L will most likely be observed in male patients with severe hypogonadism.
The Endocrine Society issued guidelines last year on treating symptoms of hypogonadism (low testosterone), listing drops in libido, muscle bulk, and height--along with hot flashes, loss of body hair, gynecomastia, and low work performance--as the main symptoms.
For males, Gonal-f(R) has been approved in 56 countries worldwide for gonadal dysfunction associated with absence of sperm in the semen or male hypogonadotropic hypogonadism.
Hypogonadism now occurs with greater frequency in sexually mature men without obvious evidence of either hypothalamic or pituitary disease.
While only 2 of the men had hypogonadism pretransplant, the women displayed a range of gonadal function abnormalities.
Hypogonadism may help explain why patients with Crohn's disease have an increased risk of osteopenia and osteoporosis, Dr.
Homozygous mice inherit the hpg gene from both parents and suffer from hypogonadism, characterized by immature sexual behavior, arrested gonadal development and infertility.
com/research/3sqllb/male_hypogonadism) has announced the addition of Global Markets Direct's new report "Male Hypogonadism - Pipeline Review, H2 2012" to their offering.