Women’s Bone Health with Mary Bouxsein, PhD
Professor of Orthopedic Surgery, Harvard Medical School
Co-Director, Center for Musculoskeletal Research
A discussion about women’s bone health across the lifespan with Dr. Mary Bouxsein.
Nina: What would you counsel your 15-year-old niece about bone health?
Dr. Bouxsein: Now is the best time to build your ‘bone bank’! Every healthy choice you make during your teen years is a deposit.
- The more bone you build now, the more you’ll have to protect you later in life.
- Be active, eat healthy (and enough!) – including calcium / dairy products + protein
- Losing your period is not normal – and is not good for your body (or your bones), so if you do lose your period, you may not be eating enough to fuel your active lifestyle. You need to eat to perform!
- Thin is NOT in.
- Being strong is where its at.
Nina: How do you counsel a 35-year-old woman who is concerned about osteoporosis?
Dr. Bouxsein: Your bones are living tissues that respond to your physical activity, diet and hormones. Now is the time to protect and optimize the bone that you have! What you do in your 30’s can have an impact on your bone health later on.
Best things to do for bone health in your 30’s:
- Regular weight bearing exercise (ie jogging, hiking, dancing)
- Do strength training to build muscle and bone: 2 – 3 times a week
- Add higher impact activities, if you can – ie, a few jumps
- Maintain a healthy diet, with particular attention to calcium (from foods, ~1000 mg/d); protein (~0.8-1.2 g/kg body weight per day), and vitamin D (600 – 800 IU per day, or plenty of time outside in the sun) – be sure you are eating enough, as energy deficiency is bad for bone and muscle!
- Hormones matter – losing your period or irregular periods is not normal, and you should talk to your doctor
- Avoid smoking and drinking too much
You can’t stop aging, but you can influence how your skeleton ages. The choices you make today—staying active, eating well, maintaining muscle strength, and understanding your personal risk—can help keep your bones strong and resilient for decades to come.
Nina: If you could wave your magic wand and bone density testing (DXA) would be covered by insurance for all women, at what age would you designate the first scan? When does a woman reach peak bone mass?
Dr. Bouxsein: Women reach peak bone mass in their late 20’s or early 30’s.
I would recommend a first bone density scan at age 45 to 50, as it is important to know your bone health heading into the menopause transition, as this may impact your personal decisions regarding menopausal hormone therapy.
Nina: When does bone loss begin and when does the rate of loss accelerate?
Dr. Bouxsein: Bone loss begins slowly after about age 35, and accelerates in the few year before and after the menopause. Women can lose 10-20% of their bone mass during the menopause transition! This amount of bone loss is approximately equivalent to a whole “T-score” – see below. That means that if you enter the menopause transition with a bone density T-score of-1.5, you could have a T-score of -2.5 after several years of rapid bone loss during menopause. This information may influence your decision to consider MHT.
When you get a bone density scan, your values are usually compared to those of a young healthy population – and presented as a “T-score” – which represents the number of standard deviations you are above or below that young healthy population.
| T-score value | Interpretation | What to do? |
| Greater than -1 | Normal | Maintain bone via healthy lifestyle*, monitor bone density |
| Between -1 and -2.5 | Low bone mass (osteopenia) | Incorporate lifestyle* changes to improve bone mass, if prior history of low-trauma fracture, consider medications for osteoporosis |
| Lower than -2.5 | Osteoporosis | Incorporate lifestyle* changes to improve bone mass, if prior history of low-trauma fracture, consider medications for osteoporosis |
* Bone-healthy lifestyle: weight bearing exercise, resistance training, balance exercises, diet with adequate protein, calcium, vit D; no smoking, no excessive alcohol
Nina: What lifestyle behaviors can prevent bone loss?
Dr. Bouxsein: Bone-healthy lifestyle: weight bearing exercise, resistance training, diet with adequate protein, calcium, vit D; no smoking, no excessive alcohol
While balance exercises and walking will not improve bone density, they are important for preventing falls – which are a key factor in fractures. If you don’t fall, you won’t get a hip or wrist fracture!
Nina: What medication can prevent bone loss? What medications can accelerate bone loss?
Dr. Bouxsein: There are several medications that can prevent bone loss, including menopausal hormone therapy, bisphosphonates, denosumab, selective estrogen receptor modulators (SERMS).
There are also several medications that can help to build bone mass that has been lost, including teriparatide, abaloparatide and romosozumab.
There are several medications that can cause bone loss, including:
- Long term glucocorticoids (ie, prednisone)
- Aromatase inhibitors for breast cancer
- Anti-seizure medications
- Some immunosuppressive drugs
Also, certain conditions, such as malabsorption disorders (ie, celiac disease, inflammatory bowel disease) can influence absorption of calcium and vitamin D from the gut, and lead to bone loss.
Eating disorders and/or losing menstrual periods (amenorrhea) can lead to bone loss.
In addition, one needs to be aware that weight loss medications (GLP-1’s) lead to both fat and muscle loss, and likely bone loss as well. While the risks to bone health are not completely known, it is important to incorporate resistance exercise to try to prevent the loss of muscle mass during weight loss.
Nina: I’ve heard scary things about side effects of some of the treatments. For example, is it true that your jaw fails to heal if you have to have a tooth removed.
Dr. Bouxsein: Trouble with jaw bone healing after a tooth extraction has been observed with bisphosphonate treatments, but the risk is very very low in women who take bisphosphonates for osteoporosis. The risk is much higher in those who take bisphosphonates as part of their cancer treatment.
The condition is termed osteonecrosis of the jaw (ONJ), and occurs in ~1 to 100 cases per 100,000 patient years, which is 0.001% to 0.1% per year — after many years of treatment, the risk remains well under 1% for most patients.
It is important to consider the risk of suffering a fracture (which can be quite high) and the disability that comes with it — versus the very low risk of ONJ. Maintaining good oral hygiene with regular cleanings will lessen the risk. If you need to have a tooth extraction, some women choose to have the procedure done before starting the bisphosphonate.
And what about femur fractures? Is that a real risk? How much of one?
I believe you are referring to “atypical femur fractures” – which are also VERY rare but also scary.
The risk of having one of these fractures is highest in women who have taken bisphosphonates for a long time (> 5 years continuously). Even then, 75 hip fractures are PREVENTED for every atypical femur fracture. It is important to weigh the risk of suffering a hip fracture – which is associated with long-term disability and increased risk of dying — with the low risk of suffering this rare adverse event.
To minimize the risk, it is now recommended to limit bisphosphonate use to less than 5 years.
There was big news for the future of bone health treatments in December, can you explain what that was?
I worked for over a decade on a project that aimed to identify a surrogate endpoint, so that new clinical trials of osteoporosis would not have to use fractures as the main outcome. In doing so, we compiled a very large database of all the clinical trials that had been done, and were able to show that the change in bone density under treatment could predict the effect the drug would have on reducing fractures. We submitted an application to the FDA, and in December, they ruled that the treatment-related change in bone density could indeed be used as the main endpoint for testing new osteoporosis therapies. This decision will allow new therapies to get to patients more quickly, and has prompted a wave of new interest, innovation and investment in the field.
What is the research you are most excited about right now?
So many things!
I am very excited about the potential use of machine learning / AI and advanced imaging methods to improve identification of individuals who may be at risk for fracture but not know it! This involves the use of routine medical imaging that is acquired for another purpose – but can be “re-purposed” to look at bone health.
I am also very excited about the new research that is testing what exercise regimens will impact bone health in women of different ages – ie, in peri / early menopause and postmenopausal women with low bone mass.
I am very excited about the new therapeutics on the horizon – both in the near term and those that are still in the horizon. I believe these will give women and their physicians more options, which is always a good thing.
And, of course, I am keen for us to understand the impact of GLP-1’s on bone health, and how best to manage the negative effects on the skeleton, if that turns out to be an issue – so important to know!
