An insulin-sensitizing drug used as a therapy for type 2 diabetes is also effective for women with a condition that can cause infertility known as polycystic ovary syndrome (PCOS). That's the finding of a small study from the University of Texas Medical Branch in Galveston.1
The drug is known as rosiglitazone, marketed under the brand name, Avandia.
"In the past, therapeutic approaches to PCOS have focused on suppressing ovarian androgen [male hormone] production or ovulation induction," wrote Vicken Sepilian, MD, and Manubai Nagamani, MD, both in the university's Department of Obstetrics and Gynecology. "Recently, insulin sensitizers have been used to reduce the level of hyperinsulinemia and its negative impact on ovarian function and possibly to prevent long-term consequences of hyperinsulinemia."
Ovarian Cysts and Other Characteristics
PCOS is a disease affecting up to 10 percent of women of reproductive age. While the cause isn't known, common symptoms include menstrual dysfunction, numerous cysts on the ovaries in many cases, high blood pressure, acne, increased levels of insulin, excess hair on the face and body, thinning of the scalp hair, weight problems and increased levels of male hormones, known as androgens. The disease can leave women infertile.2
Not all available treatments can improve all PCOS-related symptoms, and a woman's desire to be fertile may preclude treatment for PCOS in some cases despite the presence of symptoms. For women with infertility who want children, experts say treatment goals should include maintaining a normal uterine lining (endometrium), reducing high levels of androgens, improving insulin sensitivity and restoring ovulation. Insulin-sensitizing drugs have shown promise in this area, but they are not currently used as standard therapy.3
While the effectiveness of one insulin sensitizer used to treat type 2 diabetes, metformin (Glucophage, Glucophage XR), has been reported for women with PCOS, "not all, however, respond to metformin, and some experience gastrointestinal side effects with its use," wrote the researchers in this study.
In addition, there has been only very limited information available on the effectiveness of rosiglitazone as a PCOS therapy, Seplian and Nagamani wrote.
A Better Option?
To better clarify whether therapy with rosiglitazone may be a better option, Sepilian and Nagamani recruited 12 women with PCOS as test subjects. All of the patients had abnormal hair growth called hirsutism, were not ovulating, and were diagnosed with a condition known as acanthosis nigricans (ak-an-THOH-sis NYE-grih-kans), a skin disorder characterized by benign growths and abnormal pigmentation caused in this case by a hormone disorder. Each of them was insulin resistant, the researchers reported.
For the study, each woman underwent various tests, including measurements of obesity, insulin and glucose levels, and levels of certain hormones. All of the women were then treated with 4 milligrams (mg) of rosiglitazone once per day.
What Did the Drug Do?
After 6 months on therapy, each woman underwent the same tests as part of their follow-up. At that time, the researchers found that the therapy improved insulin sensitivity and glucose tolerance significantly. It also significantly lowered levels of testosterone in each woman. No significant change in obesity was seen during the 6-month period.
The researchers found that 11 of the women reverted to normal ovulatory cycles during the study period. Spontaneous menstruation also returned in each of the patients within 3 months of treatment, Sepilian and Nagamani reported.
Rosiglitazone is in a group of drugs known as thiazolidinediones (THIGH-uh-ZOH-lih-deen-DYE-owns) (TZDs), which specifically targets insulin resistance by making the body more sensitive to it.4 Insulin is a hormone that is necessary for the body to be able to use sugar for energy. Insulin takes the sugar from the blood into your body's various cells. When the body is resistant to insulin, sugar floating in the bloodstream cannot enter your cells properly. This is characteristic of type 2 diabetes,5 but insulin resistance is also found in PCOS.
Metformin is not in the same class of antihyperglycemic drugs, and is used to treat glucose intolerance in the body.6
"We conclude that rosiglitazone therapy improves insulin resistance and glucose tolerance in obese women with PCOS", as well as lowering male hormone levels and restoring spontaneous ovulation, the two researchers wrote. However, they add that rosiglitazone treatment should be halted if a woman becomes pregnant "since there have been no studies to evaluate" the drug in pregnant women.
Despite the positive findings, this is considered a preliminary study since it is difficult to extend results found in 12 patients to the larger population of women with PCOS.
1. Sepilian V, Nagamani M. Effects of rosiglitazone in obese women with polycystic ovary syndrome and severe insulin resistance. J Clin Endocrinol Metab 2004 Oct 13;[epub ahead of print].
2. Polycystic Ovarian Syndrome Association. PCOS 101.
3. Hunter MH, Sterrett JJ. Polycystic ovary syndrome: it's not just infertility. Am Fam Physician 2000 Sep 1;62(5):1079-88, 1090.
4. Blickle JF. The place of thiazolidinediones in the treatment of type 2 diabetes. [Translated from French]. Presse Med 2004 Sep 11;33(15):1034-40.
5. American Diabetes Association. Type 2 Diabetes.
6. Bristol-Myers Squibb. Glucophage Prescribing Information.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include coverage of health news for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.