Oophorectomy prior to menopause was associated with a greater risk for carotid artery thickening and bone loss more than a decade post menopause, researchers found.
After excluding women who used estrogen or bisphosphonates, women without their ovaries showed a larger rate of bone mineral density decline in the lumbar spine compared with women with intact ovaries, both 5 to 10 years after menopause (-11.2, 95% CI -19.8-minus 2.53, P=0.02) and more than 10 years after menopause (-6.45, 95% CI -14.1-1.24, P=0.08), Sara J. Mucowski, MD, of the University of Southern California Keck Medical Center in Los Angeles, and colleagues wrote online Feb. 14 in Fertility and Sterility.
The analysis adds to the growing body of research suggesting that for women without an increased risk for ovarian cancer, preserving the ovaries during pelvic surgery may have health benefits long after menopause, Mucowski told MedPage Today.
‘Older Ovaries Not Useless’
Among women who were menopausal for more than 10 years, those who had undergone prior oophorectomies lost bone mineral density at twice the rate of those whose ovaries were intact, and they showed a significantly greater progression in carotid artery intima-media thickness (CIMT), Mucowski and colleagues noted.
“Cardiovascular disease and osteoporosis are huge contributors to morbidity and mortality in U.S. women, compared to the small number of ovarian cancer deaths,” Mucowski told MedPage Today, adding that women should consider ovarian preservation when having pelvic surgery at any age unless they have an increased risk for ovarian or breast cancer.
The researchers wrote that many gynecologists maintain a “deep-rooted belief” that the ovaries provide no protective benefits after menopause, and this drives the common practice of removing them along with the uterus during pelvic surgery.
They noted that more than half (55%) of all women having hysterectomies for benign indications, without increased risk of breast or ovarian cancer, also have their ovaries removed, and this increases to 78% in women between the ages of 45 and 64.
WISH Trial Data Examined
The investigators’ analysis involved participants in the Women’s Isoflavone Soy Health (WISH) study — a randomized, double-blinded, placebo-controlled trial conducted between April of 2004 and March of 2009 to assess the impact of soy protein supplementation for reducing atherosclerosis.
All women were postmenopausal at the start of the study and all had bone mineral density scans at entry and then annually. They also had ultrasound assessments of CIMT every 6 months.
Because the trial found no group difference in bone mineral density (BMD) or CIMT between the women treated with soy and those who received placebo, data from both the treatment and control groups were used for the analysis.
The analysis included women with intact ovaries and those who had undergone oophorectomies who were 5 to 10 years post menopause, or more than 10 years post menopause.
The rate of bone mineral density change was annualized and expressed as change rate in 1000 g/cm2/year in all groups. Each bone mineral density site was analyzed individually (hip, lumbar spine, and femoral neck), and in all measured areas there were larger declines in the mean rate of bone mineral density in women without ovaries, compared with those with ovaries. However, most of these differences were not statistically significant.
Among women who were menopausal for more than 10 years, the rate of CIMT progression was statistically significantly less in women with intact ovaries compared with that of women who had had oophorectomies, however.
Study limitations cited by the researchers included the fact that just 29 of the 222 women included in the study had undergone oophorectomies, and the inclusion of women who had experienced natural menopause. “An improvement on study design would only compare hysterectomy with ovarian conservation with hysterectomy with oophorectomy to better evaluate the effects of ovarian conservation on BMD and CIMT in the post-menopausal woman,” they wrote.
‘Ovary Conservation Should Be Encouraged’
Despite the limitations, the researchers concluded that the study “adds to the mounting evidence that ovarian conservation should be offered, if not encouraged, to most women undergoing pelvic surgery for benign indications, regardless of their menopausal status.”
They noted that while a diagnosis of ovarian cancer is devastating, the lifetime risk of developing ovarian cancer is one in 70, or 1.5%, among women in the U.S., excluding risk factors such as nulliparity, family history, or genetic predisposition such as a BRCA-1 or BRCA-2 mutation.
Commenting on the study in a written press statement, American Society of Reproductive Medicine acting president Rebecca Sokol, MD, noted that the common practice of removing the ovaries during hysterectomy should be reconsidered in women with an average risk for breast or ovarian cancer.
“While the incidence of ovarian cancer increases with age and it is notoriously difficult to detect, a physician’s careful analysis of a woman’s individual risks — for cancer, as well as for bone loss or cardiovascular disease — could help her decide whether oophorectomy is the best course,” she said.
The research was funded by a National Institutes of Health grant from the National Centers for Complementary and Alternative Medicine (NCCAM), the Office of Dietary Supplements (ODS) and the Office of Research on Women’s Health (ORWH).