Many women given a diagnosis of polycystic ovary syndrome (PCOS) are overwhelmed by all the aspects of health that PCOS can impact. The specific hormonal and metabolic effects can indeed have a dizzying array of potential consequences – from the well-known such as excess facial or body hair (hirsutism) and insulin resistance or diabetes to less frequently-discussed topics such as mood disorders, male-pattern hair loss and others. Among the many questions I have been asked about PCOS, though, the topic for this blog was a first for me – is there a connection between PCOS and bone health?
For anyone interested in hormones (as an endocrinologist, this definitely includes me!), or the general intricacies of the human body, the reasons why we might hypothesize a connection are fascinating. In general, women with PCOS do not regularly ovulate, or release an egg. Because of this menstrual cycle irregularity, the estrogen produced by the ovarian follicles (fluid-filled sacs in which eggs grow) averages lower over the menstrual cycle, when compared to women who do ovulate regularly. It is well known that estrogen is a bone-protective hormone, which is part of the reason why post-menopausal status is a risk factor for osteoporosis. On the other hand, many PCOS women have high levels of androgens (the “male” hormones, including testosterone and others), and these hormones are converted to estrogens. Might this protect against a lack of regular ovulation?
To make matters more interesting, this conversion of androgens to estrogens happens in fat tissue, among other places. So it’s also possible that metrics such as body mass index (BMI), body fat distribution or body fat percentage may interact with this relationship. In other words, if you have high androgen levels and are also a bit overweight, perhaps relatively more androgen can be converted to bone-protecting estrogen! Or maybe where you carry your weight can result in local protection of bone density, but not throughout the whole body! Or perhaps some women release more inflammatory markers, which could undo the impact of fat tissue. But… only if this relationship via fat tissue is the main way androgens impact bone health, because it seems that androgens can also directly impact the cells that promote bone growth and stimulate synthesis of collagen. Further, receptors for androgen hormones seem to particularly show up in certain kinds of bone rather than others.
If all of those hypotheticals weren’t enough, let’s add another layer to an already fuzzy question. Bone health is impacted by so many factors. Peak bone mass is achieved by age 25-30, and nearly half of that bone mass is put on during adolescence. So perhaps how someone’s health and PCOS status was at a prior point in time could have a lasting impact that would be unknown if she was included in a research study in her 40s or later. Genetic, nutritional and other lifestyle (dietary calcium and vitamin D consumption and weight-bearing exercise especially!) factors all also impact our bones.
So! Where could that possibly leave us?? Well, with a list of scientific studies that shows a variety of conflicting results and inconsistent findings. Some show no connection, others suggest that PCOS is protective of bone, but yet others say that positive impact may be contingent on age or BMI, or the type of bone, or how one carries their fat tissue, or a variety of other factors. A common thread is that perhaps those women with lean PCOS, with little fat tissue and relatively lower androgen levels, may be at greatest risk. However, even their risk seems lower than women whose cycle is absent due to extreme exercise, dietary restrictions or stress (an umbrella term for this is hypothalamic amenorrhea – i.e. the brain shuts down the reproductive axis when it feels that the time and resources for pregnancy are lacking). In general, lean PCOS women still have higher estrogen levels than those with hypothalamic amenorrhea, and it’s likely enough to protect their bones.
There are not, unfortunately, studies that really have vast enough data to control for all the factors I described here and watch women with PCOS prospectively to see how their health and lifestyle over time might impact their bone density and ultimate fracture risk or incidence. The only longitudinal study I read followed 25 PCOS women over a roughly 20-year timeframe, and it basically found that these women, now post-menopausal, had similar body fat, lean mass, bone mineral density and fracture risk as women without PCOS. Well, I’ve previously written about how many of the lifelong manifestations of PCOS get confusing around the menopausal transition, and some health risks (or in this case, possible benefits!) seem to equalize as we enter the post-menopausal years. So, while this study might give us some reassurance that there’s not a huge unknown risk for PCOS women, its small size hampers how much we can really take away from it.
Suffice it to say, that even if your PCOS may be somewhat bone-protective, a healthy lifestyle with a thoughtful diet and regular exercise, including cardio and weight-bearing, will certainly bring you to your healthiest self! If you are having a period less frequently than every 3 months, make sure you’ve discussed this with your gynecologist or a PCOS specialist, to ensure that you’re not at risk for a panoply of health ramifications, including (since this is today’s topic) possible bone loss from low estrogen in thin women. The good news here is that bone health does not seem to be a topic that merits particular concern for women given the PCOS diagnosis, and following advice to prevent future osteoporosis and fractures is good for all of us, PCOS or no! You can do it!!
Dr. Rashmi Kudesia is a reproductive endocrinologist and infertility specialist who leads RMA of New York’s Brooklyn office. Dr. Kudesia specializes in treating couples who are trying to build their families.
Dr. Kudesia earned her medical degree from Duke University. She completed her residency in obstetrics and gynecology at New York Presbyterian Hospital/Weill Cornell Medical College. She completed her fellowship training in Reproductive Endocrinology and Infertility as well as a Masters of Science in Clinical Research Methods at Albert Einstein College of Medicine.
Dr. Kudesia has received numerous grants and awards for her academic accomplishments and medical research. She was awarded a Global Women’s Health certificate by Mount Sinai School of Medicine in 2011, and was nominated into the Duke Engel Society, which recognizes intellectual development, service and clinical excellence. Dr. Kudesia is the recipient of the Joan F. Giambalvo Scholarship Research Grant from the AMA Foundation in 2013, as well as multiple in-training research grants. Dr. Kudesia served as a Theme Issue Editor for the American Medical Association’s Journal of Ethics’ issue on Innovation in Reproductive Care, and has held multiple regional and national leadership positions within organized medicine.
Dr. Kudesia is an accomplished lecturer and author and has written numerous scientific research articles and manuscripts in leading medical journals. She has presented many of her research findings at national meetings, including the American Society for Reproductive Medicine (ASRM).