Birth control pills, taken alone or paired with the drug metformin, did not raise the risk of metabolic syndrome, a precursor of heart disease and diabetes in women with polycystic ovary syndrome (PCOS) even if those women were overweight, according to researchers at the Perelman School of Medicine at the University of Pennsylvania. The findings allay persistent worries about potential risks of these drugs and could mean fewer medications, fewer side effects, and better overall well-being for PCOS patients. The study was published this month in PLOS Medicine.
"Our results can help guide treatment decisions right away," said first author Anuja Dokras, MD, PhD, MHCI, director of the Penn Polycystic Ovary Syndrome Center and the Founder's Professor of Women's Health in the Department of Obstetrics and Gynecology at Penn. "Oral birth control remains a safe and effective first-line option for managing PCOS symptoms, and our research showed providers can prescribe it alone with greater peace of mind knowing that it's safe and effective for these higher risk patients. Patients should also know birth control helped improve emotions and did not cause weight gain."
What is PCOS?
In PCOS, a hormonal disorder affecting 5-6 million women and the most common cause of female infertility, there is a disruption between brain hormones and the ovaries. That leads ovaries to overproduce the male hormone androgen. People with PCOS can experience irregular or missed periods, weight gain, acne, excess facial and body hair, and an elevated risk of metabolic syndrome, a set of conditions like high blood pressure and high glucose levels that signal a risk of diabetes or prediabetes and cardiovascular disease.
For patients with PCOS, physicians often prescribe oral birth control. Nevertheless, clinicians worried that birth control pills raised the risk of heart disease and diabetes because the hormones in birth control pills, estrogen and progestin, have been shown to potentially impact insulin resistance, raise blood sugar, raise blood pressure, and occasionally shift the storage of fat. Providers were especially concerned for women who are overweight, a population already at an increased risk of heart disease and diabetes. Therefore, metformin, a first-line treatment for control of type-2 diabetes, was often paired with birth control pills to curb the risks starting at a young age.
Inside the study
Dokras and her colleagues, enrolled 240 participants (women with PCOS and elevated BMI) who were randomly assigned participants to receive birth control pills, metformin, or both for 24 weeks. At the end of the study, the prevalence of metabolic syndrome, a cluster of conditions that raise the risk of heart disease and diabetes, was similar across all three groups.
The team also found that women taking birth control pills saw small reductions in weight, waist size, and body fat around the stomach compared to baseline. Metformin alone did not lower metabolic syndrome risk, and was associated with frequent gastrointestinal side effects, including diarrhea. Participants taking metformin, either alone or with birth control, were also more likely to skip doses of the medication due to side effects.
Emphasizing quality of life
"Physicians can help patients simplify and personalize treatment while balancing the impact of medications on people's quality of life," said Dokras.
Prior studies usually examined a single cardiovascular risk factor; this was the first to examine a metabolic syndrome. Dokras notes that longer-term studies are needed to confirm these findings and measure additional metrics including mental health and heart disease effects of treatment. She hopes to also investigate whether these results hold true across diverse populations and age groups.
The research was made possible with funding from the National Institutes of Health Eunice Kennedy Shriver National Institute of Child Health and Human Development (HD091350).
