Birth Control May Increase Type 2 Diabetes Risk

Obese women taking certain forms of hormonal birth control may be at increased risk of developing Type 2 diabetes compared to obese women using nonhormonal contraception, according to a new study from the Keck School of Medicine of the University of Southern California.

The metabolic effects of progestin-only, long-acting contraception, such as the progestin-releasing IUD (a small, T-shaped device that is placed in the uterus) and a progestin-releasing device implanted under the skin, have been studied in normal-weight women. To determine the metabolic effects of these contraceptives in healthy obese, reproductive-age women, researchers observed the metabolic markers over six months in three groups of obese women: a control group that was using nonhormonal birth control options, such as condoms, the copper IUD, or sterilization; a second group using the progestin-releasing IUD; and a third group using a progestin-releasing skin implant.

The researchers found that all three categories of contraception were safe and effective, and that none caused an increase in blood pressure, weight, or cholesterol. However, women using the progestin-releasing skin implant had a 10% increase in fasting blood glucose levels, compared to a 5% increase in women using the progestin-releasing IUD and a 2% decrease in those using nonhormonal methods. Similar patterns were seen in women’s sensitivity to insulin. In a 2012 study, the same research team discovered that obese women receiving a progestin birth control shot every three months might be at increased risk for developing Type 2 diabetes.

Choosing a birth-control method requires consideration of many factors, including the patient’s lifestyle and willingness to use the method, desire for future fertility, and risk for a host of diseases — diabetes and endometrial cancer being two of them for obese women,

noted study coinvestigator Penina Segall-Gutierrez, MD, MSc.

We would like to expand our most recent study by looking at more participants over a longer period of time to see if the metabolic effects we observed in the progestin-releasing implants persist or are only temporary.

Segall-Gutierrez further noted that the progestin-releasing IUD has a number of benefits, including protection against heavy menstrual bleeding and endometrial cancer, both of which disproportionately affect obese women.

For more information, read the article “Certain Hormonal Contraceptives May Pose Risk of Type 2 Diabetes for Obese Women” or see the study’s abstract in the journal Contraception. And to learn more about contraceptive options, read this piece from the US Centers for Disease Control and Prevention (CDC).