Published
January 10, 2005

Department
of
Obstetrics &
Gynecology

Copyright
2005
The Cleveland Clinic Foundation
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Polycystic
ovary syndrome (PCOS) is the most frequently encountered endocrinopathy
in women of reproductive age. It has significant reproductive and nonreproductive
consequences.1 Women of any ethnic background
may present with PCOS. In a prospective study of 400 women of reproductive
age, 4% to 4.7% of Caucasian women and 3.4% of African American women had
PCOS.2 A similar rate of 4% to 6% has been
found in other populations. Since patients with PCOS may present with an
assortment of complaints such as menstrual
disturbance, infertility, hirsutism, and acne, their point of entry
into the medical system may be by way of a primary care physician, gynecologist,
endocrinologist, or dermatologist. Thus, all these disciplines need to be
familiar with this syndrome and its long-term consequences. |
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| DEFINITION
AND DIAGNOSIS |
Historically, there
has been a lack of consensus regarding the features that define PCOS.
A meeting convened by the National Institutes of Health (NIH) in 1990
stressed three key features necessary for the diagnosis of PCOS:
-
The patient must
exhibit ovulatory dysfunction.
-
There must be evidence
of clinical hyperandrogenism and/or biochemical hyperandrogenemia.
-
Other disorders
must be excluded, such as nonclassic congenital adrenal hyperplasia,
androgen-secreting tumors, and hyperprolactinemia/thyroid disorders.
Since 16% to 25% of
the normal population may have polycystic-appearing ovaries by ultrasound,3 the presence of polycystic ovaries was considered to be suggestive but
not diagnostic of PCOS.
However, the Rotterdam
European Society of Human Reproduction/American Society for Reproductive
Medicine (ESHRE/ASRM)-Sponsored PCOS Consensus Workshop Group that convened
in 2003 now requires the existence of two of the following three criteria
to make the diagnosis of PCOS:4
Even after these criteria
have been met, other etiologies that may lead to hyperandrogenism must
still be excluded. To exclude congenital adrenal hyperplasia, a basal
early-morning level of 17-alpha hydroxyprogesterone is performed in the
follicular phase. Total testosterone level may be evaluated to rule out
an androgen-secreting tumor. Although luteinizing hormone (LH) levels
are high in most women with PCOS, the Rotterdam consensus panel considered
it unnecessary to assess the LH level routinely. Finally, free testosterone
and dehydroepiandrosterone sulfate (DHEAS) levels may be checked when
clinical suspicion is high for PCOS but the patient does not exhibit clinical
signs of hyperandrogenism. |
| PATHOPHYSIOLOGY |
The basic pathophysiologic
defect is unknown in PCOS; however, since this disorder tends to cluster
in families, a genetic etiology is believed likely. Hyperandrogenism is
a common finding in first-degree relatives of women with PCOS. The rates
of PCOS in mothers and sisters of patients diagnosed with PCOS were 24%
and 32%, respectively.5 Increased insulin
resistance has been noted in mothers and sisters of women with PCOS.6 Several large research groups are actively searching for a genetic cause
of this syndrome. The mode of inheritance is uncertain at this point,
and the role of shared environmental factors such as diet and lifestyle
in the presentation of the disease is unknown. Loci proposed and investigated
as possible PCOS genes include CYP11A, the insulin gene, and a
region near the insulin receptor gene.7 The wide range of PCOS symptoms likely plays a significant role in the
inability thus far to identify a specific gene mutation.
Although the pathophysiology
of PCOS is not clear, a variety of biochemical abnormalities have been
described with this syndrome. Hyperinsulinemia is noted in 50% to 70%
of PCOS patients. It is defined as impaired action of insulin on glucose
transport and antilipolysis in adipocytes in the presence of normal insulin
binding. Hyperinsulinemia causes or exacerbates hyperandrogenemia. Increased
insulin levels at the ovarian level lead to increased androgen production
from the ovarian thecal cells. In an in-vitro model, Nestler et al8 demonstrated increased testosterone production by theca cells of women
with PCOS exposed to insulin compared with testosterone production from
the theca cells of normal women. Also, by suppressing hepatic production
of sex hormone binding globulin (SHBG), insulin increases unbound levels
of testosterone. At the level of the granulosa cell, insulin amplifies
the response of granulosa cells to LH. Thus, these cells undergo abnormal
differentiation and premature arrest of follicular growth, and thus anovulation.
Elevated androgen
levels also lead to decreased levels of SHBG. Greater unbound androgen
levels are likely to produce a greater clinical response, such as hirsutism and acne. Most patients
with PCOS will show evidence of clinical hyperandrogenism. However, a
small proportion will not, which may warrant a biochemical investigation.
In such cases, measurement of free testosterone should be considered,
although most currently used direct assays for free testosterone have
limited value for the evaluation of the hyperandrogenic woman. The methods
recommended at the consensus meeting to determine free testosterone are
by equilibrium dialysis or by calculation of free testosterone from measurement
of SHBG and total testosterone, or ammonium sulfate precipitation. DHEAS
may be measured, since a small percentage of patients with PCOS will have
isolated elevations in this hormone. However, there were not enough data
for the consensus meeting to support the routine measurement of androstenedione.
Another key feature
of PCOS is altered gonadotropin dynamics. Multiple studies have shown
both higher LH pulse and amplitude in women with PCOS.9 While a higher LH level drives the ovarian thecal cells to produce more
androgens, insufficient follicle-stimulating hormone (FSH) may be the
more immediate cause of anovulation. In most women, LH levels are elevated,
or the LH/FSH ratio is high; however, the mean LH pulse amplitude is attenuated
in obese women with PCOS.10 Thus, the
LH value or LH/FSH ratio would not be helpful in establishing this diagnosis
in such patients. |
| SIGNS
AND SYMPTOMS |
PCOS
symptoms have a gradual onset. Although symptoms of PCOS may exist at the
time of menarche, most patients do not seek help until their early to mid-20s.
Menstrual
Irregularities/Reproductive Issues
Abnormal vaginal bleeding is a typical complaint that ranges from amenorrhea
to oligomenorrhea to menorrhagia and metrorrhagia. Since patients with
PCOS experience irregular and incomplete endometrial shedding, endometrial
hyperplasia and cancer must be aggressively ruled out; thus, an endometrial
biopsy should be considered. Adults with prolonged episodes of bleeding
unresponsive to treatment and those with irregular bleeding and long durations
of amenorrhea should undergo endometrial biopsy regardless of their age.
Other studies such as ultrasound of the uterus and endometrial lining
may assist with this decision. Fifteen percent to 30% of women with PCOS
claim to have regular periods despite documented anovulation.
Because these patients are anovulatory, they present with infertility
issues. They may also have increased incidence of pregnancy loss and pregnancy
complications.11 12 Spontaneous abortion occurs in one third of all pregnancies in women with
PCOS, which is double the rate in normal women. After pregnancy is established,
perinatal mortality is increased at least 1.5 times.13 Pregnancy complications can include gestational diabetes, pregnancy-induced
hypertension, and increased rate of intrauterine fetal demise. Currently,
it is unclear whether PCOS independent of obesity leads to poor obstetric
outcome. In a case-control study, Haakova and colleagues compared the
pregnancy outcome of a group of women with PCOS with that of a group of
healthy weight-matched women. The investigators were unable to show a
higher rate of pregnancy complications in the PCOS group.14
Skin
Manifestations
Depending on ethnic background skin manifestations may vary. Compared
to Asian women, Middle eastern or Mediterranean women are more likely
to complain of hirsutism. Other women's primary skin complaint may be
acne. Excessive growth of terminal hair is noted on the upper lip, sideburn
area, chin, and periareolar, abdominal, back, and buttock areas. Signs
of virilization are lacking. In some cases, there is evidence of alopecia,
which can be extremely disturbing to patients. Other dermatologic findings
may include acanthosis nigricans and skin tags, which may be manifestations
of insulin resistance.
Obesity
and Metabolic Abnormalities
Although the prevalence of obesity is high in patients with PCOS, in large
series the rate varies. Depending on the series, the rate of obesity in
the PCOS population ranges from 38% to 87%.15 Variables that may influence this number include diagnostic criteria and
geographic and environmental factors. Since obesity is associated with
insulin resistance, many women with PCOS have insulin resistance, but
insulin resistance in PCOS is independent of obesity. Dunaif and colleagues
showed that the insulin sensitivity of nonobese women with PCOS approached
that of obese controls. Obese women with PCOS had higher insulin resistance
than cycling obese women in the control group.16
PCOS patients are
at higher risk of metabolic syndrome, which is a group of cardiovascular
risk factors that include dyslipidemia, type 2 diabetes mellitus, hypertension,
and obesity. In a study of 254 women with PCOS compared with controls,
the prevalence of impaired glucose tolerance was 31% vs 10.3% and the
prevalence of type 2 diabetes was 7.5 % vs 1.5%.17 At the Rotterdam ESHRE/ASRM-Sponsored PCOS consensus workshop, three of
the five criteria in Table 1 were considered necessary for a diagnosis
of metabolic syndrome.
| Table
1: |
| Criteria
for Diagnosis of Metabolic Syndrome |
| Risk
Factor |
Cutoff |
| Abdominal
obesity |
>88
cm |
| Triglycerides |
>150
mg/dL |
| High-density
lipoprotein cholesterol |
<50
mg/dL |
| Blood
pressure |
>130/>85
mm Hg |
| Fasting
and 2-hour glucose from oral glucose tolerance test |
110-126
mg/dL and/or 2 h glucose 140-199 mg/dL |
| Adapted
from reference 4. |
|
| THERAPY |
Treatment is typically
directed at the presenting symptoms of PCOS. While multiple treatment
options are available, few randomized trials exist to help provide a clear
treatment guideline.
Lifestyle
Modification
In conjunction with medical therapy, focus should be directed at lifestyle
modification by diet and exercise if the patient is overweight. Even small
amounts of weight loss have established menstrual cyclicity, increased
spontaneous ovulation and pregnancy rates, and increased sensitivity to
ovulation-induction medications.18 Also,
the rate of miscarriages decreased and live births increased.19 A significant impact on the metabolic consequences of PCOS is also expected
with weight loss, since insulin and triglyceride levels decrease and high-density
lipoprotein cholesterol increases.
Oral
Contraceptive Pills
Oral contraceptive pills are typically the first line of therapy for management
of irregular bleeding in women with PCOS not yet interested in conception.
Cyclic withdrawal of estrogen and progesterone leads to complete endometrial
shedding and resolution of most abnormal bleeding. Exposure to the progestin
in oral contraceptives leads to reduction in the risk of endometrial cancer
and hyperplasia. In addition, the steroids cause a decrease in LH levels
and a subsequent decrease in androgen production. Finally, they also increase
SHBG production, and thus the resulting decreased free testosterone levels
lead to diminished hirsutism and acne.
Antiandrogens
If the degree of hirsutism and acne is significant, antiandrogens are
used. Although they are slow to show results (a minimum of 6-9 months),
a significant change in thickness of hair shaft and reduction of sexual
hair growth can be seen. Spironolactone, up to 200 mg/day, is the most
common antiandrogen used in PCOS patients in the United States. Moghetti
and colleagues20 demonstrated that there
is no difference in the effectiveness of spironolactone, flutamide, or
finasteride. Due to their possible teratogenic impact on the development
of a male fetus, they are rarely used alone. Usually, they are given in
conjunction with oral contraceptive pills.
Ovulation-Induction
Agents
Ovulation can be induced with clomiphene citrate in more than 80% of anovulatory
patients. This drug is typically the first line of therapy, although pregnancy
rates are only about 40%. Other agents that may be used to induce follicular
growth and subsequent ovulation include insulin-sensitizing agents, exogenous
gonadotropins, and aromatase inhibitors.
Insulin-Sensitizing
Agents
These agents increase tissue sensitivity to insulin action. Metformin
is a biguanide drug that has traditionally been used for management of
frank diabetes. It is believed to increase peripheral glucose uptake,
and since it does not precipitate hyperinsulinemia, it does not cause
hypoglycemia. A recent review of the literature21 shows that, on average, body mass index decreased by 4% and androgen levels
decreased by 20% with the use of metformin compared with placebo. However,
this does not translate into a significant impact on hirsutism.
Metformin regularizes
menstrual cyclicity, typically within 3 months of initiating the drug.
If ovulation induction has not been achieved within 3 months of initiating
metformin in anovulatory infertile women, clomiphene citrate is typically
added to the regimen. Several studies show higher ovulation rates in patients
on metformin and clomiphene citrate than those achieved with placebo or
clomiphene citrate alone.22 23 Currently, there is no clear consensus on whether all patients with PCOS
should initially undergo a trial of metformin to induce ovulation or whether
they should be placed on metformin after clomiphene citrate has failed
to induce ovulation. The most recent Cochrane database of systemic reviews
on the use of insulin-sensitizing agents in patients with PCOS concludes
that metformin is justified as first-line therapy for ovulation induction.24
Another area of potential controversy is the use of metformin for the
sole restoration of menstrual cyclicity. Since metformin does not consistently
lead to regular periods, it cannot be recommended as the first line of
therapy for this symptom; oral contraceptives are still considered the
first line of therapy for cyclic endometrial shedding. However, since
oral contraceptives can exacerbate insulin resistance, metformin may be
considered for morbidly obese women who are at significant risk of insulin
resistance.
A review of the literature
indicates that use of metformin in women with PCOS decreased fasting insulin
levels, low-density lipoprotein, and blood pressure.24 However, because of the lack of long-term data, it is unknown whether
these changes translate into a decreased likelihood of cardiovascular
disease and diabetes. Hence other pharmacologic interventions may be necessary,
as directed by an internist, to address the specific metabolic abnormality.
Finally, use of metformin as a replacement for exercise and diet modification
cannot be advocated. The Diabetes Prevention Program Research Group demonstrated
that, although metformin use significantly reduces the frequency of type
2 diabetes in nondiabetic patients who have high serum glucose concentrations,
exercise has a greater impact in reducing the frequency of diabetes.25
Metformin is used
in doses of 1,500 to 2,000 mg/day. Gastrointestinal symptoms are its main
side effects and include nausea, vomiting, diarrhea, and flatulence. These
symptoms are typically transient. Gradual increase of the dose may decrease
these side effects. This medication is contraindicated in women with hepatic
or renal impairment and in those with conditions that increase the risk
of lactic acidosis. Other insulin-sensitizing agents that are currently
available are rosiglitazone and pioglitazone.
Laparoscopic
Ovarian Drilling
Laparoscopic ovarian drilling is the modern version of the ovarian wedge
resection. The premise is destruction of stromal tissue leading to decreased
androgen production and subsequent change in the hormonal profile. Testosterone
levels decrease and LH levels seem to drop after ovarian drilling. Hirsutism
has been noted to improve for up to 9 years. Ovulatory rates of up to
74% and pregnancy rates of 50% to 70% have been reported.26 Given that these results are similar to those noted with the use of metformin,
it may be more prudent to proceed with metformin therapy initially in
anovulatory women not at risk for tubal factor infertility. Laparoscopy
carries the inherent risks associated with surgery. In addition, this
procedure may be associated with subsequent peri-adnexal adhesions. |
| OUTCOMES |
In more recent years,
awareness has developed of some of the long-term implications of PCOS
that extend well into the postmenopausal years. The physician is responsible
not only for offering medical treatment options, but also for educating
the patient regarding the possible long-term consequences of the syndrome.
Endometrial
Cancer
Women with PCOS have chronic anovulation. The endometrial lining is exposed
to unopposed estrogen for long durations. These patients are believed
to be at increased risk of endometrial cancer. However, there is minimal
epidemiologic evidence to support this theory.27
Diabetes
There is clear evidence that women with PCOS have an increased likelihood
of impaired glucose tolerance and are at increased risk for type 2 diabetes
mellitus.17 Women with PCOS who have a
family history or are obese are at even greater risk of developing diabetes.
Unfortunately, fasting glucose concentration is a poor predictor of diabetes
in this population. But impaired glucose tolerance is known to be a risk
factor for development of frank diabetes. Since the prevalence of impaired
glucose tolerance and diabetes is high in obese PCOS patients,7 the Rotterdam ESHRE/ASRM sponsored PCOS consensus group advises performing
a screening 2-hour oral glucose tolerance test on obese women.
Cardiovascular
Disease
Cardiovascular risk factors are increased in patients with PCOS when compared
with weight-matched controls.28 High-density
lipoprotein cholesterol levels are lower and triglyceride levels and very
low-density lipoprotein cholesterol are higher.29 Multiple studies on women with PCOS seem to demonstrate an increase in blood pressure. However,
blood pressure is affected by a variety of factors that include weight,
genetics, and stress. Thus, it is not clear whether lean insulin-resistant
women with PCOS are also at higher risk for developing hypertension.
It has been very difficult to tease out the individual effects of PCOS
and obesity on cardiovascular risk factors, since obesity can negatively
affect blood pressure, the lipid profile, and insulin resistance. Finally,
an increase in coronary artery calcification has also been reported in
such patients.30 All these factors are
believed to lead to a higher incidence of cardiac events in women with
PCOS. However, despite these "risk factors," there is no consistent
epidemiologic evidence yet that these patients in fact do suffer from
an increased incidence of coronary
heart disease.31 32
Return
to Medical Index |
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