What is Osteoporosis?
It may not be obvious, but our bones are an active tissue, constantly remodelling themselves, resorbing and depositing their mineral structures to accommodate for use. This process can be referred to as bony metabolism. Children and young adults with healthy exercise habits usually have a metabolism that favours an increase in bone density. However, bony production tapers off, and will naturally slide downwards to some extent with increasing age.
For a number of reasons, bony metabolism can get out of balance, where the body removes more than it replaces, causing the bone to become weaker over time. Osteopenia is the name given to an excessive decline in bone mass and architecture, whereas osteoporosis is the term used when a threshold of decline according to age and sex has passed.
Osteoporosis is characterised by a higher risk of fractures, most commonly in the hip and spine, but also other areas of the body such as the wrist and foot. For many it is a silent disease until a fracture has been discovered, so a strong focus in management of this condition in the broader public is in preventative behaviours and therapies.
Who is affected by it?
Osteoporosis is a widespread concern, particularly amongst post-menopausal women. According to statistics, half of women past menopause and one fifth of similarly aged men will go on to develop an osteoporotic fracture. These are staggering figures, and serve as a reminder that osteoporosis is a major health concern that should sit further forward in our minds, particularly as many of these debilitating fractures are preventable with targeted medical treatment and lifestyle interventions. Younger people may also experience osteoporosis, usually when a combination of risk factors have taken effect.
What are the risk factors?
1. Hormone Balance
Bony metabolism is controlled by an array of circulating hormones produced outside of the skeleton, that are responsive to changes in the body that can be related or seemingly unrelated to the bones themselves. Two key hormones involved in this system are oestrogen and testosterone. Temporary periods of low oestrogen may occur due to breastfeeding, or when the menstrual-cycle is interrupted for other reasons (such as stress or ill health), but the most significant and lasting reduction in oestrogen occurs during menopause, which is why osteoporosis is such a big issue in the post-menopausal population. Low testosterone is also a significant risk factor, with inhibition of hormone production detected in 50% of elderly men with hip fractures.
As mentioned earlier, regular weight-bearing exercise is crucial to maintain or increase bone density. Guidelines recommend 45min of aerobic exercise, plus progressive strength 2-3 times per week. Exercises should also target balance and flexibility. Temporary immobility will reduce bone strength, but this is generally reversible when activity is resumed.
They say you can’t choose your parents, and genetic factors are important in this case too: there is a significantly greater risk of osteoporosis if it runs in the family.
4. Medical Risks
Loss of bone density is a side effect of several medications that may be prescribed for common chronic diseases. There are also medical conditions that contribute to loss of bone density, either directly from local tissue pathology, or due to sustained bed rest and immobility. It is a good idea for anyone with long-term prescriptions to have a conversation with their GP around potential side-effects that may accumulate over time. Bone density may also be an important discussion point when recovering from a significant illness.
5. Nutrition and Lifestyle
A healthy, balanced diet should contain an adequate source of calcium. Calcium is essential for building and maintaining healthy bones. Some people with modified diets or gastrointestinal concerns may benefit from a discussion with their GP or dietician regarding supplements. Vitamin D is necessary for the body to absorb calcium. It is produced by the body in response to sunlight, but can also be obtained from the diet. Vitamin D deficiency is seen more commonly in the elderly who may not spend as much time outside.
How is osteoporosis diagnosed?
Unfortunately for many people, osteoporosis is discovered after a fracture has occurred. However, doctors can arrange imaging to assess bone density in those at risk. Anyone who has concerns in this regard should bring it up with their GP, especially if they are perimenopausal or identify any of the risk factors described above.
What happens after a fracture?
Some osteoporosis fractures are obvious and related to incidents, such as hip and wrist fractures, with the management depending on the nature of the injury. Other fractures, particularly ones located in the spine, may go undetected for a period of time. For example, a study in the Netherlands of 566 women over 50 living with risk factors for osteoporosis found 31% of these women already had a significant vertebral fracture.
The consequences of progressing osteoporotic fractures in the spine, aside from pain, relate to changes in its morphology. A loss of vertebral height, and commonly an increase in the curvature, changes the space for the chest and abdominal cavities in front. This can cause breathing restrictions and a protruding belly, plus a loss of muscle strength. In the bigger picture, osteoporotic fractures cause a loss of mobility and independence in later life, heightened falls risk and an increase in mortality from other causes.
Clearly, once early signs of osteoporosis have been identified, it is imperative to work on prevention. Doctors will work to help identify and address contributing factors, plus monitor bone density changes over time. As alluded to earlier, lifestyle factors such as diet and exercise play a major role in prevention and management of osteoporosis, as well as certain medication such as Biophosphonates.
How can Physiotherapy help?
Weight-bearing exercise, such as walking and running provides crucial stimulation to preserve bone density. Some bones benefit from the strength of muscular attachments, however the fundamental need for healthy bones is weight-bearing load.
There are many reasons why one may not get enough exercise, but a common reaction we see to the usual aches and pains that creep in is to walk less. Many people transition towards low-impact exercise such as cycling and swimming as a more comfortable method of maintaining fitness. Whilst this is beneficial to heart and respiratory health, it is not an effective method of preserving bone density.
Physiotherapists can assist with an exercise program to target preservation and development of bone density. This will be tailored to your ability and can progressively challenge your strength and accommodate any other joint issues or injuries. The first step is to book a clinical strength assessment so that we can assess your needs and develop your program.
Image Source: https://msk.org.au/osteoporosis/