Androgen replacement therapy
Encyclopedia
Androgen replacement therapy is a hormone treatment often prescribed to counter the effects of male Hypogonadism
. It is also prescribed to lessen the effects or delay the onset of normal male aging. Additionally, androgen replacement therapy is used for men who have lost their testicular function to disease, cancer, or other causes.
As men enter middle age they may notice changes caused by a relative decline in testosterone: fewer erections, fatigue, thinning skin, declining muscle mass and strength, more body fat. This dissatifaction with the changes of aging has led to the development of the idea of androgen replacement therapy.
Male hormones are called androgen
s from Greek words andro meaning man, and gen meaning giving birth to. Primary among them is the natural hormone testosterone
, which is produced in the testes, ovaries and adrenals. Females also produce testosterone in the adrenals and as a precursor to estrogen
, but the amount of circulating testosterone is generally far less than in males, although the ranges on the two genders overlap. Both sexes also produce an androgen precursor called dihydroepiandrostene (DHEAS) from which the body can make androgens. Androgens cause the secondary sex characteristics of males: facial hair, thicker skin, low body fat, deeper voice, muscularity, penis and scrotal growth and darkening, broad shoulders, body hair, erection of the penis, etc. With increasing age, testosterone production declines, and many of these changes start to reverse.
This "decline of maleness" with age has given rise to a term: "andropause
". This term implies a parallel with menopause
in women, although the two states are by no means equivalent. The term manopause has also been used in the popular press. The scientific term is PADAM, an acronym for Progressive Androgen Deficiency of the Aging Male.
There are several artificial androgens, including nandrolone
and various other manipulations of the testosterone molecule. Androgen replacement is via patch, tablet, pill, cream or gel; or depot injections given into fat or muscle.
Users report an increased alertness and well-being, heightened libido and erection ability, increase in lean muscle mass and concomitant decrease in body fat.
Adverse effects of testosterone supplementation include minor side effects such as acne and oily skin, and more significant complications such as increased hematocrit
which can require venipuncture
in order to treat, exacerbation of sleep apnea
and acceleration of pre-existing prostate cancer
growth in individuals who have undergone androgen deprivation. Another adverse effect may be significant hair loss and/or thinning of the hair. This may be prevented with Propecia (Finasteride), which blocks DHT (a byproduct of testosterone in the body), during treatment. Exogenous testosterone also causes suppression of spermatogenesis
and can lead to infertility. It is recommended that physicians screen for prostate cancer with a digital rectal exam and prostate-specific antigen (PSA) level before starting therapy, and monitor hematocrit and PSA levels closely during therapy.
There is the possibility of abuse: some athletes may demand far higher levels of androgen than normal in order to out-perform others, other people may feel they require greater doses in order to achieve what they perceive as a feeling of greater well-being.
, and may improve associated features such as anemia
, and fatigue.
In addition, a number of other effects of testosterone have led to research into possible therapeutic roles in:
Hypogonadism
Hypogonadism is a medical term for decreased functional activity of the gonads. Low testosterone is caused by a decline or deficiency in gonadal production of testosterone in males...
. It is also prescribed to lessen the effects or delay the onset of normal male aging. Additionally, androgen replacement therapy is used for men who have lost their testicular function to disease, cancer, or other causes.
As men enter middle age they may notice changes caused by a relative decline in testosterone: fewer erections, fatigue, thinning skin, declining muscle mass and strength, more body fat. This dissatifaction with the changes of aging has led to the development of the idea of androgen replacement therapy.
Male hormones are called androgen
Androgen
Androgen, also called androgenic hormone or testoid, is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of male characteristics in vertebrates by binding to androgen receptors...
s from Greek words andro meaning man, and gen meaning giving birth to. Primary among them is the natural hormone testosterone
Testosterone
Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...
, which is produced in the testes, ovaries and adrenals. Females also produce testosterone in the adrenals and as a precursor to estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
, but the amount of circulating testosterone is generally far less than in males, although the ranges on the two genders overlap. Both sexes also produce an androgen precursor called dihydroepiandrostene (DHEAS) from which the body can make androgens. Androgens cause the secondary sex characteristics of males: facial hair, thicker skin, low body fat, deeper voice, muscularity, penis and scrotal growth and darkening, broad shoulders, body hair, erection of the penis, etc. With increasing age, testosterone production declines, and many of these changes start to reverse.
This "decline of maleness" with age has given rise to a term: "andropause
Andropause
Andropause or male menopause, sometimes colloquially called "man-opause" is a name that has been given to a menopause-like condition in aging men...
". This term implies a parallel with menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
in women, although the two states are by no means equivalent. The term manopause has also been used in the popular press. The scientific term is PADAM, an acronym for Progressive Androgen Deficiency of the Aging Male.
There are several artificial androgens, including nandrolone
Nandrolone
Nandrolone is an anabolic steroid that may be present naturally in the human body, albeit in minute quantities of less than 0.4 ng/ml. Nandrolone is most commonly sold commercially as its decanoate ester and less commonly as a phenylpropionate ester...
and various other manipulations of the testosterone molecule. Androgen replacement is via patch, tablet, pill, cream or gel; or depot injections given into fat or muscle.
Users report an increased alertness and well-being, heightened libido and erection ability, increase in lean muscle mass and concomitant decrease in body fat.
Adverse effects of testosterone supplementation include minor side effects such as acne and oily skin, and more significant complications such as increased hematocrit
Hematocrit
The hematocrit or packed cell volume or erythrocyte volume fraction is the percentage of the concentration of red blood cells in blood. It is normally about 45% for men and 40% for women...
which can require venipuncture
Venipuncture
In medicine, venepuncture, venopuncture or venipuncture is the process of obtaining intravenous access for the purpose of intravenous therapy or for blood sampling of venous blood. This procedure is performed by medical laboratory scientists, medical practitioners, some EMTs, paramedics,...
in order to treat, exacerbation of sleep apnea
Apnea
Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...
and acceleration of pre-existing prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
growth in individuals who have undergone androgen deprivation. Another adverse effect may be significant hair loss and/or thinning of the hair. This may be prevented with Propecia (Finasteride), which blocks DHT (a byproduct of testosterone in the body), during treatment. Exogenous testosterone also causes suppression of spermatogenesis
Spermatogenesis
Spermatogenesis is the process by which male primary germ cells undergo division, and produce a number of cells termed spermatogonia, from which the primary spermatocytes are derived. Each primary spermatocyte divides into two secondary spermatocytes, and each secondary spermatocyte into two...
and can lead to infertility. It is recommended that physicians screen for prostate cancer with a digital rectal exam and prostate-specific antigen (PSA) level before starting therapy, and monitor hematocrit and PSA levels closely during therapy.
There is the possibility of abuse: some athletes may demand far higher levels of androgen than normal in order to out-perform others, other people may feel they require greater doses in order to achieve what they perceive as a feeling of greater well-being.
Therapeutic indications
Androgen replacement has a direct role in the treatment of hypogonadismHypogonadism
Hypogonadism is a medical term for decreased functional activity of the gonads. Low testosterone is caused by a decline or deficiency in gonadal production of testosterone in males...
, and may improve associated features such as anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, and fatigue.
In addition, a number of other effects of testosterone have led to research into possible therapeutic roles in:
- erectile dysfunctionErectile dysfunctionErectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
- osteoporosisOsteoporosisOsteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
- diabetes mellitusDiabetes mellitusDiabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
- chronic heart failure
- dementiaDementiaDementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
, but the evidence base is small and the balance of benefit needs to be clarified