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Introduction
Sex hormones, or steroidal hormones, are important for hair growth.
A lack of one or more of these hormones could lead to a absence
of body hair in adults, but more significantly an over expression
of steroidal hormones and/or a lack of antagonists to steroidal
hormones can result in the development of pattern baldness. For
women with a diagnosis of androgenetic alopecia, a blood test to
examine hormone levels might be desirable to see if there is a systemic
cause of the excessive androgen activity. But for men with an androgenetic
alopecia diagnosis, a blood test is very rarely done.
Although hyperandrogenicity in men is possible with some prostate
and adrenal gland disorders, these conditions are rare. Unless there
are multiple symptoms pointing towards a prostate or adrenal gland
problem, hormone testing is not generally conducted for men. Male
pattern baldness has a distinctive presentation that makes it easy
to identify and little additional information is gained from a blood
analysis. Almost all men with pattern baldness have normal steroid
hormone ranges.
You can of course insist on a blood test if the medical insurance
system in your country allows. The most basic hormone testing in
males often only includes FSH and testosterone and doctors may be
reluctant to do more, but a more comprehensive test would provide
more information. A comprehensive blood test for men might include:
- Sex hormone binding globulin (SHBG)
- Estrogens (usually only the estradiol (E2) form is tested)
- Dehydroepiandrosterone sulfate (DHEAS) and/or Dehydroepiandrosterone
(DHEA)
- Total testosterone (T)
- Free testosterone (that testosterone which is not bound to other
molecules like SHBG)
- Androstenedione (possibly androstenediol too)
- Follicular stimulating hormone (FSH)
Although dihydrotestosterone (DHT) is the primary promoter of androgenetic
alopecia it is not generally tested because DHT is a relatively
unstable molecule and levels can vary significantly over a short
space of time. In addition, the DHT in the blood stream is not a
particularly good reflection of the DHT in hair follicles. Steroid
hormone responsive hair follicles produce their own DHT through
enzyme conversion of DHEAS and T that they receive through the blood
stream. To define excessive systemic androgen activity doctors look
at the DHEAS, testosterone, and androstenedione results.
Note that in terms of understanding androgenetic alopecia, blood
test results only present part of the story. The blood test results
indicate what is going on systemically in terms of hormone production.
A blood test does not provide an insight into hormonal activity
in the skin and hair follicles. Skin and hair follicles produce
their own enzymes that can convert mild androgens like DHEA into
potent androgens like DHT. So it is possible to have normal blood
test results but have significant androgenic activity in the hair
follicles. A normal blood test result does not rule out a diagnosis
of androgenetic alopecia.
Standard
test ranges of hormones in men
Note; only the basic ranges are listed here. The values for children
can be significantly different. Normal ranges will be slightly different
in different laboratories as there is no calibration of the tests
between different labs.
|
Hormone / antagonist
|
Life stage
|
Value
|
| Progesterone (nanograms per milliliter or nano-moles
per liter) |
Adult |
< 1.0 ng/ml
(< 3.18 nmol/L) |
| 17-Hydroxyprogesterone (nanograms per deciliter
or nano-moles per liter) |
Prepubertal |
< 1.1 ng/dl
(< 3.3 nmol/L) |
| |
Adult |
5 – 250 ng/dl
( 0.15 – 7.5 nmol/L) |
| Estradiol (picograms per milliliter or pico-moles
per liter) |
Prepubertal |
< 10 pg/ml
(< 37 pmol/L) |
| |
Pubertal |
< 23 pg/ml
(< 84 pmol/L) |
| |
Adult |
< 60 pg/ml
(< 185 pmol/L) |
| Estrone (picograms per milliliter or pico-moles
per liter) |
Adult |
10 – 50 pg/ml
(37 – 185 pmol/L) |
| Estriol (nanograms per milliliter or nano-moles
per liter) |
Adult |
< 2 ng/ml
(< 7 nmol/L) |
| FSH (units per liter) |
Adult |
1.0 – 12.0 U/L |
|
LH (units per liter)
|
Adult |
2.0 – 14.0 U/L |
| SHBG (nano-moles per liter) |
Adult |
6 – 50 nmol/L |
| Dehydroepiandrosterone (DHEA) (nanograms per deciliter
or nano-moles per liter) |
< 6 years |
20 – 130 ng/dl
(0.7 – 4.5 nmol/L) |
| |
6-8 years |
20 – 275 ng/dl
(0.7 – 9.5 nmol/L) |
| |
8-10 years |
31 – 345 ng/dl
(1.1 – 12 nmol/L) |
| |
10-20 years |
110 – 900 ng/dl
(3.8 – 31.2 nmol/L) |
| |
> 20 years |
160 – 800 ng/dl
(5.6 – 27.8 nmol/L) |
| Dehydroepiandrosterone sulfate (DHEAS) (micrograms
per deciliter or micro-moles per liter) |
1-8 years |
10 – 20 µg/dl
(0.3 – 0.5 µmol/L) |
| |
8-10 years |
30 – 50 µg/dl
(0.8 – 1.4 µmol/L) |
| |
10-12 years |
30 – 40 µg/dl
(0.8-1.1 µmol/L) |
| |
12-14 years |
80 – 140 µg/dl
(2.2 – 3.8 µmol/L) |
| |
14-50 years |
110 – 690 µg/dl
(3.0 – 18.7 µmol/L) |
| Androstenedione (nanograms per milliliter or nano-moles
per liter) |
< 6 years |
0.1 – 0.2
(0.3 – 0.7 nmol/L) |
| |
6-8 years |
0.1 – 0.3
(0.3 – 1.0 nmol/L) |
| |
8-10 years |
0.1 – 0.3
(0.3 – 1.0 nmol/L) |
| |
10-12 years |
0.3 – 0.7
(1.0 – 2.4 nmol/L) |
| |
12-14 years |
0.5 – 1.0
(1.7 – 3.5 nmol/L) |
| |
> 14 years |
0.8 – 2.3
(2.8 – 8.0 nmol/L) |
| Androstenediol (nanograms per milliliter) |
|
0.2 – 2 ng/ml |
| Total testosterone - morning sample (nanograms
per deciliter or nano-moles per liter) |
Prepubertal |
8 – 14 ng/dl
(0.28 – 0.49 nmol/L) |
| |
Pubertal |
84 – 480 ng/dl
(2.91 – 6.24 nmol/L) |
| |
Adult |
300 – 1000 ng/dl
(10.4 – 34.7 nmol/L) |
| Free testosterone - morning sample (picrograms
per milliliter or pico-moles per liter) |
20 –40 years |
15.0 – 40.0 pg/ml
(520 – 1387 pmol/L) |
| |
41 –60 years |
13.0 – 35.0 pg/ml
(451 – 1213 pmol/L) |
| |
61 –80 years |
12.0 – 28.0 pg/ml
(416 – 971 pmol/L) |
| Dihydrotestosterone (nanograms per milliliter
or nano-moles per liter) |
Prepubertal |
< 3 – 13 ng/ml
(< 0.1 – 0.4 nmol/L) |
| |
Adult |
30 – 100 ng/ml
(1.0 – 3.4 nmol/L) |
| Deoxycorticosterone (nanograms per milliliter
or pico-moles per liter) |
Prepubertal |
2 – 34 ng/ml
(61 – 1030 pmol/L) |
| |
Adult |
2 – 19 ng/ml
(61 – 576 pmol/L) |
| Cortisol (micrograms per milliliter or nano-moles
per liter) |
Adult morning |
5 – 20 µg/ml
(140 – 552 nmol/L) |
| |
Adult afternoon |
2.5 – 10 µg/ml
(69 – 276 nmol/L) |
| Prolactin (nanograms per milliliter) |
|
0 – 15 ng/ml |
An
explanation of test results for sex hormones in men
Testosterone - Understanding the hormone test results from
men is much simpler than analyzing test results from women. The
average adult male, not surprisingly, produces significantly more
testosterone than women do. A high level of total testosterone is
not necessarily a problem in terms of androgenetic alopecia susceptibility.
If the testosterone is mostly bound testosterone then the hormone
is unable to activate testosterone receptors. What is more important
for understanding androgenetic alopecia is the level of free testosterone
- those hormone molecules capable of interacting with androgen receptors
on cells. The percentage of testosterone in the male body that is
free is typically 0.3% - 5%. An optimal level is about 2% free,
unbound testosterone. Excessively high levels of free testosterone
may suggest a hyperandrogenic problem. Free testosterone levels
are highest in the morning and gradually drop throughout the day
so normal values for a blood sample taken in the afternoon will
be slightly lower than those shown above. Testosterone production
is stimulated by Leydig cells in the testicles. Low levels of testosterone
combined with low FSH and LH are diagnostic of hypogonadotropic
hypogonadism.
Dehydroepiandrosterone (DHEA) - However, the total testosterone
and free testosterone levels only present part of the androgen story.
Androgen responsive hair follicles produce enzymes capable of converting
other, less potent androgen hormones into, testosterone and dihydrotestosterone.
The primary source converted is DHEA or DHEAS. Potentially, the
more DHEA in the blood, the more that can be converted to more potent
androgens in the hair follicles. A high DHEA and/or DHEAS level
signals a potential increase in androgenetic alopecia susceptibility.
Dehydroepiandrosterone sulfate (DHEAS) is the sulfated form of Dehydroepiandrosterone
(DHEA). DHEA is a relatively unstable molecule and it mostly gets
converted to DHEAS before circulating in the blood stream. For the
purpose of understanding androgenetic alopecia, DHEA and DHEAS can
be regarded as basically the same thing.
Luteinizing Hormone (LH) - In men, LH stimulates Leydig
cells and production of testosterone. A problem with LH levels alone
is very rarely seen, so testing is only needed if the testosterone
level is found to be abnormally low.
Prolactin - A level two or three times that of normal may
indicate a pituitary tumor, such as a prolactinoma, which may lead
to decreased sperm production. Elevated levels can be treated with
the drug bromocriptine.
Sex Hormone Binding Globulin (SHBG) - Increased androgen
production in general leads to lower SHBG. The normal range for
SHBG in men is lower than in women. SHBG is an antagonist to testosterone.
SHBG binds to testosterone and renders it inactive. Bound testosterone
cannot interact with androgen receptors on cells so it has no impact
on hair follicles. A reduced SHBG level suggests a possible increase
in susceptibility to androgenetic alopecia. However, while a high
SHBG level is theoretically good in terms of avoiding androgenic
hair loss, too much SHBG can be a problem for men. Men require a
certain amount of free testosterone to maintain muscle mass, sex
drive, and possibly bone mass too. An excessively high SHBG level
can reduce the net action of androgens in maintenance of these body
systems. So an SHBG level at the upper end of the normal range is
the ideal situation limiting the risk of androgen action on hair
follicles while permitting an acceptable level of free testosterone
to maintain other body functions.
Normal
ranges for hormone tests in men references
- Fischbach FT. A manual of laboratory and
diagnostic tests. Lippincott, Philadelphia, ISBN: 039755186X.
1998
- Kratz A, Lewandrowski KB. Case records
of the Massachusetts General Hospital. Weekly clinicopathological
exercises. Normal reference laboratory values. N Engl J Med. 1998
Oct 8;339(15):1063-72.
- Greenspan FS, Gardner DG. Basic & Clinical
Endocrinology. 7th edition. Norwalk:
Appleton-Lange, ISBN: 0071402977,
2003
- Griffin JE, Wilson JD. Disorders of the
testes and the male reproductive tract. In: Wilson JD, Foster
DW, editors. William's Textbook of Endocrinology. 8th ed. Philadelphia:
Saunders Co., 1992
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