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What
is polycystic ovary syndrome (PCOS)
Polycystic
ovary syndrome (PCOS) is a very common disease in women. Two doctors,
Stein and Leventhal, first identified the problem in 1935. However,
despite being known about for many years and despite extensive research
no one knows why it occurs and it is not possible to accurately
predict who will develop PCOS. PCOS can develop at any stage of
life. It can affect teenage girls as well as adult women. If it
remains undiagnosed and untreated, PCOS can potentially become a
life threatening disease.
 There are several fundamental clinical features of PCOS. The symptoms
are expressed to differing degrees in different women. Some may
have just one symptom and others may have several or all symptoms.
Hirsutism is quite common in PCOS. This involves excess body hair
growth, particularly on the chest, arms and legs plus the beard
region. Hirsutism usually progresses slowly in patients with PCOS
so it may not be immediately apparent. Menstrual irregularities
may also develop in PCOS. Menstrual problems may be traced to the
time of menarche in some women, for others the problems occur much
later in life. PCOS may also be associated with obesity. Up to 50%
of women develop this symptom. Some women also develop non insulin
dependent diabetes (NIDDM). Young women who develop PCOS are believed
to be at increased risk for cardiovascular disease. Symptoms may
also include androgenetic alopecia and/or acne. PCOS may develop
at any time of life and so the androgenetic alopecia symptom may
also develop at any time. PCOS can be present for some time before
the hair loss develops and becomes noticeable.
PCOS can present with a variety of different biochemical abnormalities.
The most consistent abnormality is hypersecretion of androgens.
This may involve elevation of free testosterone (T) and possibly
dehydroepiandrosterone sulfate (DHEAS). There can also be variable
increased production of Lutenizing hormone (LH), acyclic high estrogen
production, low sex hormone binding globulin (SHBG) levels, and
hyperinsulinemia (too much insulin production).
There is some evidence that genes may promote susceptibility towards
development of PCOS. For example, CYP11a, is a gene coding for P450
side chain cleavage, it seems to be a key susceptibility locus for
development of hyperandrogenism in PCOS. Inheritance of PCOS susceptibility
seems to be equally probable from the maternal as from the paternal
side of the family. It is estimated that a woman's risk for developing
PCOS is up to 40% if she has an affected sister, but a lower risk
rate if other family members are affected.
While PCOS may involve susceptibility genes the varied presentation
of the disease suggests that other non-gene factors influence onset
and progression. These factors might include environmental influences,
such as fat and carbohydrate consumption, exercise level, peripubertal
stress and/or hormonal exposure; and additional genetic defects,
such as those that regulate insulin secretion or determine body
type. However, there is no reliable evidence to prove these external
factors are involved or how exactly they might influence PCOS development.
How
does polycystic ovary syndrome (PCOS) promote hirsutism
PCOS can promote hirsutism by both direct and indirect methods.
In PCOS there is usually hypersecretion of androgen hormones that
directly influences androgen sensitive hair follicles, and subnormal
sex hormone binding globulin (SHBG) levels that also affects androgen
levels in the blood. Indirectly, PCOS can promote hirsutism through
increased insulin levels
Not every woman with PCOS develops hirsutism. High estrogen production
levels may be present and this will contribute to the heterogeneity
of symptoms, especially hirsutism. Estrogen is an indirect antagonist
of testosterone. So while high levels of testosterone may promote
hirsutism, the androgen activity may be blocked to some degree by
the high levels of estrogen production.
What are
the goals of therapy for polycystic ovary syndrome (PCOS)?
Goals of therapy for patients include decreasing levels of free
androgens in the blood, blocking androgen activity in target tissues,
stabilizing the endometrium, and reducing insulin resistance. Oral
contraceptive pills, antiandrogens, and cosmetic treatments may
be used to treat hirsutism, acne, or menstrual irregularity. Oral
contraceptive pills or medroxyprogesterone acetate may also used
to prevent onset of endometrial hyperplasia or carcinomas.
Advice on weight loss and changes to nutrition may be given to
help reduce obesity if it is a symptom. In turn, weight loss may
help improve improve hyperandrogenism, menstrual irregularity and
may prevent NIDDM and cardiovascular disease. Insulin-sensitizing
agents show promise in terms of decreasing hyperandrogenism, restoring
ovulatory cycles, and treating infertility. Unless the underlying
cause of the PCOS is corrected, medical therapy will need to be
continued indefinitely.
What
is polycystic ovary syndrome (PCOS) references
- Franks
S, Gharani N, McCarthy M. Genetic abnormalities in polycystic
ovary syndrome. Ann Endocrinol (Paris). 1999 Jul;60(2):131-3.
- Kashar-Miller
M, Azziz R. Heritability and the risk of developing androgen excess.
J Steroid Biochem Mol Biol. 1999 Apr-Jun;69(1-6):261-8.
- Gordon
CM. Menstrual disorders in adolescents. Excess androgens and the
polycystic ovary syndrome. Pediatr Clin North Am. 1999 Jun;46(3):519-43.
- Kahn JA,
Gordon CM. Polycystic ovary syndrome. Adolesc Med. 1999 Jun;10(2):321-36.
- Futterweit
W. Polycystic ovary syndrome: clinical perspectives and management.
Obstet Gynecol Surv. 1999 Jun;54(6):403-13.
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