ORAL CONTRACEPTIVE USE BY YOUNG WOMEN DOES NOT CONTRIBUTE TO WEIGHT GAIN, STUDY SHOWS

September 11, 2002

Young women have lost one excuse in their battle against the post-adolescent bulge. 

Penn State College of Medicine researchers at the Penn State Milton S. Hershey Medical Center recently published the results of a new, long-term study showing that oral contraceptive use during adolescence is not associated with weight gain or increased body fat.

"Until now, most of the major studies on the effects of oral contraceptive use have looked at women aged 20 and over," said Tom Lloyd, Ph.D., principle investigator on the study, professor of health evaluation sciences, Penn State College of Medicine, and director of the Penn State Young Women's Health Study. "This study provides new information about the effects of oral contraceptive use on adolescents and young women."

The study, titled "Oral Contraceptive Use by Teenage Women Does Not Affect Body Composition," was published in the August 2002 issue of Obstetrics and Gynecology

"Oral contraceptives prevent pregnancy the same way in teenage women as they do in adult women," said Richard Legro, M.D., co-investigator and associate professor of obstetrics and gynecology, Penn State College of Medicine. "However, we know very little about how a teenager's metabolism may be affected by oral contraceptive use. Because young women's bodies change so much during adolescence, we felt it was important to understand whether using oral contraceptives during these developmental years causes metabolic and physiologic changes."

This study is part of the Penn State Young Women's Health Study which is an ongoing observational study begun in 1990 with the enrollment of 112 healthy female adolescents who are representative of Caucasian females attending public schools in Pennsylvania. The Penn State researchers continue to follow the natural progression of cardiovascular, reproductive and bone health in these women.

The oral contraceptive study involved 66 females, 39 of which used oral contraceptives for a minimum of six months, were still users at age 21, and had used oral contraceptives for an average of 28 months. The 27 non-users had never used oral contraceptives.

From ages 16 to 21, researchers took blood samples from the participants once a year to measure cardiolipoprotein levels. From ages 12.5 to 21, they took body composition measurements with dual energy x-ray absorptiometry. Participants filled out questionnaires with information about physical activity so that researchers could adjust results for both body mass index and level of activity.

Results revealed that height, weight, body mass index, body fat and most cardiovascular disease risk factors were similar for oral contraceptive users and nonusers. Low-density lipoproteins, total cholesterol and triglycerides were slightly higher in users than in nonusers, although still within the normal range.

"The long-term effects, if any, of this alteration in lipid profiles is unknown," Lloyd said.

This study supports previous ones that show that the latest generation of oral contraceptives with a lower dose of hormones have more influence on blood lipid patterns of women under 25 than over 25. It's unknown whether those changes have clinical significance.

"Although perceived weight gain is a common complaint among women who use oral contraceptives, previous studies have shown that this is not the case with adult women and this study provides evidence that the body composition of young women using oral contraceptives also is not affected," Legro said. "Based on this new information, we suggest that potential users be counseled by their health care providers accordingly."

The study was funded by the General Clinical Research Center at Penn State Milton S. Hershey Medical Center and the Public Health Service. Study contributors included: Hung Mo Lin, Sc.D., Amy E. Matthews, and Christina M. Bentley.

Contact: Valerie Gliem vgliem@psu.edu

Last Updated March 19, 2009