The Importance of Bone Health and Parkinson’s Disease
Falls can be a major difficulty for people with Parkinson’s disease (PD), leading to fractures and other injuries. People with PD are at increased risk of fracture, with a four times higher risk of hip fracture as compared with the general population. Often, a person with PD will return to their baseline after recovery from a fracture. However, for some, a fracture, and its resultant immobility, as well as the effects of a potential surgery and hospitalization, will lead to permanent decline in their condition. Therefore, steps to prevent falls is a key goal of PD management.
But not every fall can be prevented, so an often-overlooked part of managing someone who tends to fall is assessing bone density and treating low bone density if possible. A fall that could result in a fracture in someone with low bone density could be much less of a problem in someone with normal bone density.
Bone density is assessed using a simple test called dual-energy X-ray absorptiometry (DEXA) also known as bone densitometry. X-ray technology is used to measure the density of the hip and spine bones. Depending on the level of mineralization of the bones, the test can diagnose osteoporosis, which literally means “porous bones”.
Bone Density and Parkinson’s Disease
It is especially important for people with PD to have their bone mineral density assessed, not only because they are at increased risk of falls, but because studies show that people with PD have lower bone mineral density than age-matched controls.
There are several avenues of research to suggest why people with PD have bones that are less dense than the general population:
- Studies done in cell culture and animals show that dopamine receptors are expressed in bone cells and influence bone strength. A decrease in dopamine signaling that occurs in PD may therefore decrease bone strength
- Levodopa treatment of PD may reduce the rate of bone formation
- In PD, Lewy bodies can be found in the hypothalamus, the area of the brain responsible for secreting the hormones that regulate bone density
In addition, low bone density can be a direct consequence of the symptoms of PD. A person with PD may:
- Perform less weight bearing activity than the general population, which typically results in weaker bones
- Spend less time outside in the sun and experience increased levels of malnutrition, both of which can lead to lower Vitamin D levels and weaker bones
- Experience weight loss which is associated with weaker bones
Treatments for Low Bone Density
Good news! Low bone density can be successfully treated – including in people with PD.
Exercise & Bone Health
Weight bearing activities and exercise are vital in maintaining bone strength. This adds yet another reason why exercise is so important in PD management. (To learn more about getting started with exercise, check out our free Be Active & Beyond exercise guide, which is also available in Spanish.) Consider joining an exercise class or enlisting the help of a physical therapist or personal trainer – but look for ones that are specialized for people with PD to ensure that they are safe and appropriate. There are many exercise classes you can join virtually from home.
Medications for Bone Health
There are also many available medications for osteoporosis to improve bone mineralization and decrease risk of fracture. For these reasons, it is very important for bone density to be tested so that treatment can be initiated if necessary. Based on your test results, your doctor may talk to you about medication options (in addition to exercise) to increase your bone mineralization.
Vitamin D and its association with Parkinson’s Disease
Besides the clear importance of Vitamin D in maintaining bone health in people with PD, there have also been numerous studies investigating other associations between Vitamin D and PD. There are conflicting results as to whether low levels of Vitamin D are associated with an increased risk of developing PD. In addition, some studies demonstrate an increased rate of Vitamin D deficiency in people with PD as compared to age matched controls and even link low Vitamin D levels to increased severity of PD symptoms. There are conflicting results as to whether Vitamin D supplementation can reduce symptoms of PD. More studies are necessary to clarify these associations.
Vitamin D for Bone Health
Vitamin D is a critical nutrient which is derived from two sources – your diet and exposure to sunlight. There are not many foods that contain Vitamin D, so about 70-80% of our Vitamin D needs to be obtained from sunlight (Ultraviolet B from sunlight converts a steroid precursor in the skin to Vitamin D.) Vitamin D plays many roles in the body, including helping with calcium absorption from food and supporting mineralization of bone. (To get some Vitamin D from your diet, try salmon, canned tuna, and mushrooms which naturally contain Vitamin D. There are also many milk, yogurt, and orange juice options that are fortified with Vitamin D.)
Because people tend to spend a lot of time inside, especially in the winter, Vitamin D deficiency is a very common problem in the general population. For those with PD who might have an even harder time getting outside, Vitamin D deficiency can be more pronounced.
Vitamin D levels can be tested in blood. If it is low, over the counter supplements are readily available. Talk with your doctor about whether your Vitamin D level should be checked and how much supplementation you should take.
Bone Fractures and Parkinson’s Disease
Despite optimization of fall prevention and bone strength, people with PD may still experience fractures. The hip is a common site of injury which typically requires surgical intervention. It is reassuring to note, that should this be necessary, immediate post-op complications of hip fracture surgery are the same in people with PD as compared to age matched controls.
However, more long-standing complications after hip fracture do occur in people with PD including:
- Increased immobility, morbidity, and mortality at one year
- Increased discharge to a rehab facility or long-term care institution
Clearly, prevention of falls and fractures should be a priority for people with PD. Be sure to talk to your doctor about the many options you have to increase your chances of success in this area.
Trial of Zoledronic Acid (TOPAZ) and Parkinson’s: Study
An ongoing clinical trial is seeking participants to study the use of Zolendronate in the prevention of fracture in people with PD. Zolendronate is a medication already approved by the Food and Drug Administration for the prevention of fractures in people with osteoporosis. The TOPAZ study is investigating the role of this medication in preventing fractures in people with PD. You do not need to travel anywhere to participate in the study. Enrollment is online and you will receive a study kit by mail. A research nurse makes a one-time visit to the home. Follow up visits are conducted via email or phone. To learn more about this study, visit the study website.
Tips and Takeaways
- Falls and resultant fractures are common in people with PD. You can read more about falls in a previous blog.
- Although fall prevention in PD is vital, ensuring strong bones is another way to prevent fractures
- There are fairly easy ways to improve your bone density, and decrease your risk of fractures
- Talk with your doctor about having your bone density checked via a DEXA scan and get treated if it shows that you have low bone density
- In addition, talk with your doctor about having your Vitamin D levels checked and take supplementation if warranted
- Consider joining the TOPAZ clinical trial which is investigating fracture prevention in people with PD