Photo: Penina Segall-Gutierrez, assistant professor of clinical obstetrics and gynecology, and family medicine at the Keck School of Medicine of USC (by Gary Mancuso)
Obese women may increase their risk for developing type 2
diabetes by using the birth control shot marketed as Depo-Provera,
according to a small study by researchers from the
Keck School of Medicine of the
University of Southern California (
USC).
The first to examine the drug’s effect on obese women, the study
suggests that other forms of long-term birth control, namely
intrauterine contraception, may be a more effective choice for
overweight women.
“Obese women have a higher risk of developing type 2 diabetes and other
cardiovascular diseases. They also have an increased risk for pregnancy
complications. We don’t want to prescribe a contraceptive that will
push these women from borderline hyperglycemic to diabetic,” said
Penina
Segall-Gutierrez, M.D., assistant professor of clinical obstetrics
and gynecology, and family medicine at the Keck School of Medicine.
Segall-Gutierrez led the
study,
“Deterioration in cardiometabolic risk markers in obese women during
depot medroxyprogesterone acetate use,” which appears in the January
2012 issue of the journal
Contraception.
Depot medroxyprogesterone acetate (DMPA) is a progestin-only
contraceptive that is administered by injection every three months.
DMPA and other progestin-only methods are the only hormonal
contraceptives recommended by the American Congress of Obstetricians
and Gynecologists for obese women older than 35. Because most oral
contraceptives increase the risk for developing blood clots, they are
not recommended for obese women, who are more susceptible to clots than
normal-weight women.
For the study, researchers compared the insulin sensitivity, body mass
index, blood sugar and cholesterol levels of 15 women (five of normal
weight and 10 who were overweight) before injection and 18 weeks after.
The participants, recruited over a seven-month period at the Women’s
and Children’s Hospital of the
Los Angeles County+USC
Medical Center, received an injection of DMPA upon acceptance into
the study and another 12 weeks later.
The researchers found that both normal-weight and obese women became
more insulin resistant after receiving DMPA, which means that their
bodies became less effective at lowering blood sugars. However, it
appears that the normal-weight women were able to compensate by
producing more insulin. The data suggest that weight gain, an increase
in insulin resistance, or both play a role in the increased
susceptibility for diabetes among obese women who use DMPA.
Future research should observe effects over a longer period of time and
compare how obese women using non-hormonal contraception fare to those
using DMPA, Segall-Gutierrez said. Despite the small sample studied,
Segall-Gutierrez said the results are useful for clinicians who counsel
obese women about contraception.
“Depo is used by 6 percent of American women, but it’s more popular
than the intrauterine device or implant,” she said. “These are other
forms of contraception that don’t increase one’s risk for diabetes.”
Co-authors include Anny H. Xiang, Ph.D.;
Richard M. Watanabe, Ph.D.;
Enrique Trigo;
Frank
Z. Stanczyk, Ph.D.; Xinwen Liu;
Ronna Jurow, M.D.;
and
Thomas A.
Buchanan, M.D., all of the Keck School of Medicine. The research
was funded by an anonymous donor.