According to researchers, genetics may explain why some women gain weight when using a popular method of birth control. According to a study conducted by researchers at the University of Colorado Anschutz Medical Campus, a woman’s genetic make-up may cause her to gain weight when using a popular form of birth control.
“For years, women have claimed that birth control causes weight gain, but many doctors have failed to take them seriously,” said Aaron Lazorwitz, MD, assistant professor of Obstetrics/Gynecology and Family Planning at the University of Colorado School of Medicine. “Now, we’ve looked at the genetics and discovered that the way genes interact with certain hormones in birth control may help explain why some women gain more weight than others.”
The study, which was published today in the journal Contraception, focused on the etonogestrel contraceptive implant. The rod-shaped implant is inserted beneath the skin and contains etonogestrel, a type of progestin that inhibits ovulation.
The study concentrated on the etonogestrel contraceptive implant, a rod-shaped implant containing etonogestrel, a type of progestin that inhibits ovulation. It is inserted beneath the skin and is regarded as one of the most effective methods of birth control.
A woman’s genetic make-up may cause her to gain weight when using a popular form of birth control, according to a study from researchers at the University of Colorado Anschutz Medical Campus.
The findings, which were published online in the journal Contraception, revealed that 73.9 percent of the women gained weight, with the researchers calculating that the median weight change was 3.2 kg gained over an average of 27 months.
The researchers examined medical records to calculate weight changes from the time the implant was inserted to the time the women enrolled in the study. They discovered a median weight change of +3.2 kg or about 7 pounds gained over an average of 27 months of use in 276 ethnically diverse subjects. The majority of subjects, 73.9 percent, gained weight.
Lazorwitz and his colleagues investigated the genetics of the participants and how they might interact with the birth control drug within the implant using pharmacogenomics, the study of how genes affect a person’s response to drugs.
They hypothesized that variants in genes encoding proteins that degrade and interact with progestin and estrogen hormones could be the key. Finally, they discovered that genetic variants in estrogen receptor 1 (ESR1) were linked to clinically significant weight gain in some study participants.
ESR1 is located on chromosome 6. When activated, it encodes an estrogen receptor that participates in cellular hormone binding and DNA transcription. Previous research has discovered links between ESR1 genetic variants and how well other medications work.
When compared to the other women in the study, women who had two copies of the ESR1 rs9340799 variant gained over 30 pounds more while using the contraceptive implant. The study focused on the etonogestrel contraceptive implant, but other birth control medications may have similar interactions with genes that cause weight gain.
“It’s critical to understand how individual genetic variation influences a woman’s risk of adverse weight gain while using exogenous steroid hormone medications,” Lazorwitz said. For the time being, it is impossible to predict who will be affected.
Health care providers can counsel patients about potential weight gain or recommend other forms of birth control, such as copper IUDs, which do not contain hormones. “As our understanding of pharmacogenomics in women’s health expands,” Lazorwitz said, “we can develop individualized counseling that may reduce the incidence of hormone-related adverse effects, improve patient satisfaction, and help prevent future health risks associated with weight gain.”
“It’s critical to understand how individual genetic variation influences a woman’s risk of adverse weight gain while using exogenous steroid hormone medications,” Lazorwitz said.
According to the authors, there is currently no way to predict who is more susceptible to weight gain, but healthcare providers could recommend other forms of birth control, such as copper IUDs that do not contain hormones, to women who are concerned.