Feb. 4, 2005 -- The diet drug Xenical may help treat polycystic ovary syndrome (PCOS), a major cause of infertility.
No one knows exactly what causes PCOS. There is currently no cure for the condition, but treatment can relieve symptoms and prevent long-term complications such as type 2 diabetes, heart disease, and the increased risk for endometrial cancer and potentially breast cancer.
Losing extra weight is often part of the plan for overweight PCOS women. It's estimated that 10%-50% of PCOS patients are obese, say British researchers in The Journal of Clinical Endocrinology & Metabolism's February issue.
Shedding even a modest amount of weight can help. In women with PCOS, losing less than 10% of initial body weight has been shown to increase ovulation frequency, improve fertility, reduce levels of the male hormone testosterone, and cut high levels of blood fats and blood sugar, say the researchers, including V. Jayagopal of the Michael White Centre for Diabetes and Endocrinology at the University of Hull in the U.K. Weight loss has been shown to improve insulin resistance.
Besides diet and exercise, PCOS patients may take Metformin. The drug lowers blood sugar, improves insulin's action, and may be used to induce ovulation, regulate menstrual cycles, and improve fertility in women with PCOS.
The British study compared Xenical with Metformin in 21 obese young women with PCOS. The women were about 27 years old. Their average body mass index (BMI) was almost 37; a BMI of 30 or higher is obese. The women were not taking other drugs, had never been pregnant, and weren't trying to conceive.
First, the women had their weight and blood pressure recorded. Their blood was screened for cholesterol, triglycerides, blood sugar, and testosterone levels. Those tests were repeated before the drugs were randomly assigned and at the study's end.
Next, the women started a weight maintenance diet.
Eight weeks later, 11 women were given 500 mg of Metformin three times daily for three months.
The other 10 women received 120 mg of Xenical three times daily before each meal, also for three months.
Xenical has not been proven to help PCOS, and it does not affect appetite. Taken before meals, it blocks dietary fat from being absorbed.
By the study's end, the Xenical group had a 4.7% weight loss, compared with 1.02% for the Metformin group. Both groups had similar reductions in the level of the male hormone testosterone. Menstrual and ovulation changes weren't monitored, due to the study's size and short length.
"We know that Metformin is a proven and effective treatment for women with polycystic ovary syndrome," says Andrea Dunaif, MD, in a news release. Dunaif is president-elect of The Endocrine Society and is a professor and chair of the endocrinology division at Northwestern University's medical school in Chicago.
"This study suggests that weight loss medications may be an effective treatment option for not only the obesity but also the testosterone excess associated with PCOS. Further research is clearly warranted to determine where this class of medications will fit into the treatment of PCOS," says Dunaif.
Both drugs had some side effects. Four Metformin patients had mild nausea, two had heartburn, and one had mild abdominal pain. Those symptoms disappeared within four weeks, and no doses were reduced. Two women taking Xenical had mild to moderate flatulence and oily stools occasionally throughout the study.