The sex hormone estrogen greatly influences the health of women across the lifespan, from protecting our bones to playing a key role in the menstrual cycle. However, in gynecological conditions like endometriosis and uterine fibroids, estrogen the promotes the growth and spread of the disease.
“If estrogen is the ‘bad guy’ in uterine fibroids and endometriosis, it is the ‘good guy’ in bone health,” said Dr. Ayman Al-Hendy, a gynecologic surgeon and researcher at the University of Chicago who studies the origin of these conditions and develops novel treatments for them. This interesting dichotomy raises the question: Do endometriosis and uterine fibroids impact bone health?
Because endometriosis and fibroids are estrogen-dependent conditions, the prevalence of these diseases correlates with fluctuations in estrogen levels over a woman’s lifetime. For instance, estrogen levels in the body remain low until puberty, so endometriosis and fibroids do not typically appear until after a girl has her first period. After puberty, rates of endometriosis and fibroids increase throughout the lifespan until patients reach menopause, when estrogen production decreases, alleviating symptoms of these conditions for most women.
On the flip side, estrogen is a positive factor in bone health. It promotes the activity of osteoblasts — cells that generate new bone tissue — and mitigates the activity of osteoclasts — cells that break down and remodel bone tissue. This is why as women transition into menopause and their estrogen levels decrease, their risk for weaker bones and osteoporosis increases.
Al-Hendy noted that while there is very little research on the impact of fibroids and endometriosis on bone health, the research that has been done indicates these estrogen-driven gynecological conditions neither promote nor prevent bone loss in patients.
Although the conditions themselves don’t appear to have direct adverse effects on bone health, certain treatment options for endometriosis and fibroids require consideration of long-term bone health. Gonadotropin‐releasing hormone (GnRH) agonists and antagonists are medications used to regulate production of estrogen in order to reduce the growth of fibroids and endometriosis lesions and improve other symptoms like pain and heavy bleeding. However, because these medications reduce production of estrogen, putting women in a menopause-like state, they can cause long-term depreciation of bone mineral density, Al-Hendy said. To counteract this effect, researchers led by Al-Hendy recently published a study showing that a pill combining a GnRH antagonist with small doses of estrogen can help with fibroids symptoms and protect bone health.
Hysterectomy (surgical removal of the uterus) is a treatment that may be considered for women with endometriosis or fibroids when other less invasive options are exhausted. If women and their health care providers choose hysterectomy, Al-Hendy noted that leaving the ovaries intact is preferred to avoid early menopause and preserve bone health. In extreme cases where removal of the ovaries (oophorectomy) is necessary, he urged ample counseling for the patient on the risks and benefits of hormone therapy to supplement estrogen that the body is no longer making.
Al-Hendy stressed that all women should engage in positive behaviors to maintain bone health throughout their lifespan. “Even outside of endometriosis and uterine fibroids, bone health is not discussed among patients and doctors pre-menopause,” he said. Al-Hendy identified options such as calcium and vitamin D supplements, as well as lifestyle approaches such as limiting caffeine and alcohol intake, exercising, and avoiding smoking, that can increase chances of healthier bones over the lifetime.
In terms of future outlooks, Al-Hendy expressed the need for additional basic and clinical research on bone health. “There need to be more studies on bone health in premenopausal women. We have very little data on that,” he said. With more data on what happens to bones physiologically before menopause, we can better understand the intersection of fibroids and endometriosis with bone health.
Al-Hendy encouraged health care providers to discuss with endometriosis and fibroid patients the variety of treatment options available to them and their potential effects on different aspects of health, including bone density. As researchers continue to explore novel therapies for endometriosis and fibroids, considering the effects of these therapies on all aspects of women’s health and quality of life will be key to furthering women’s holistic health.
You can find more information on endometriosis, uterine fibroids, and menopause on the SWHR website. Also, check out SWHR’s Endometriosis Toolkit: A Patient Empowerment Guide here.
SWHR blog content on bone health is supported by a sponsorship from Amgen. SWHR maintains editorial control and independence over blog content.