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Polycystic ovarian syndrome (PCOS) is a very common reproductive disorder. Women
with PCOS frequently have irregular menstrual cycles, excessive body hair, are
overweight, and suffer from infertility. Many women with PCOS have a decreased
sensitivity to insulin for which their bodies compensate by overproducing insulin. The
resulting high levels of insulin may contribute to excessive production of androgens
(male hormones, such as testosterone) and contribute to ovulation disorders. In
addition to reproductive problems, women with PCOS have a higher chance of developing
medical problems, such as Type 2 (non-insulin dependent) diabetes, high blood pressure,
and heart disease. By the age of 40, up to 40% of PCOS patients develop impaired glucose
tolerance or clinical diabetes.
Given the strong evidence that excess insulin plays a role in the development of
PCOS, it is reasonable to assume that reducing circulating levels of insulin may
help restore normal reproductive function. This may be accomplished by weight
loss, improved nutrition, and exercise. These behavioral changes should be the
first lines of therapy for an overweight woman with PCOS.
Recently, new drugs approved by the FDA for the treatment of Type 2 diabetes have
shown promise for PCOS. These drugs, known as insulin sensitizing agents, have been
shown to improve the body’s response to insulin, thereby reducing the need for excess
insulin and restoring the levels to normal. The best studied insulin sensitizing
agent available in the United States for women with PCOS is metformin (Glucophage®), a
biguanide. Metformin reduces circulating insulin and androgen levels and restores
normal ovulation in some women with PCOS. Even if metformin alone does not restore
ovulation, it may improve a woman’s response to fertility drugs. Gastrointestinal
irritation, especially diarrhea, is a common side effect. These symptoms usually
improve after a few weeks. Lactic acidosis is a rare, but serious, adverse effect
of metformin. Metformin is not recommended for patients with kidney, lung, liver,
or heart disease.
Rosiglitazone (Avandia™) and pioglitazone (Actose®), which belong to the thiazolidinedione
group of antidiabetic agents, are also available in the United States for women with
PCOS. Thiazolidinediones have been shown to reduce hyperandrogenism and restore ovulation
in some PCOS patients. Liver toxicity is the main concern with these agents. Liver
tests should be performed every two months for the first year and periodically thereafter.
These medications should not be started in women with any evidence of liver disease.
So far, the new insulin sensitizing agents have not been linked to birth defects in animals
or humans, but they are not recommended for use during pregnancy. Metformin should also
be temporarily stopped prior to surgery or X-ray procedures that use intravenous contrast.
Unlike ovulation induction drugs, insulin sensitizing agents have little or no risk of
multiple pregnancies. More clinical studies are needed to determine the outcomes, risks,
and complications when these medications are used to treat PCOS. Although results from
clinical studies have been encouraging, the use of these medications in women with PCOS
is still considered investigational. In general, metformin is used as the first insulin
sensitizing agent; thiazolidinediones may be considered if metformin is ineffective or
not tolerated by the patient.
Present data suggest the use of insulin sensitizing agents for ovulation induction in
PCOS patients who want to conceive. Because these medicines correct the underlying
metabolic abnormalities associated with PCOS, it is plausible that their long-term
use may delay the emergence or reduce the likelihood of developing Type 2 diabetes
and cardiovascular disease. Since data are lacking, however, long-term use of insulin
sensitizing agents for this purpose cannot be recommended at present.
Reference: ASRM Fact Sheet (08/01)
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