Exercise as it relates to Disease/Osteopenia, delaying progression through exercise

What is Osteopenia?
The condition, osteopenia, is identified by low bone mineral density and can lead to osteoporosis as one ages. Bone mineral density peaks before the age of 30,(1) after which it slowly decreases. Osteopenia is diagnosed by a DXA (Dual-energy X-ray absorptiometry) scan which measures bone mineral density. This provides a T Score, which is the measurement used to assist in determining whether or not an individual has osteopenia or osteoporosis. It is worth noting that a T score of less than -1 does not necessarily mean that an individuals bone density is decreasing. An individual may naturally have decreased bone density and may have had so for their entire life. Further testing should be conducted to and compared to the original T score for further clarification.

What are the symptoms of osteopenia?
Most people will not know that they have osteopenia until they suffer a fracture, by which time they are usually diagnosed with osteoporosis. Osteoporosis is called a "silent disease" as it does not present any external symptoms.

What are the risk factors for becoming osteopenic?
As osteopenia is a possible precursor to osteoporosis, the risk factors are similar, such as: age, gender, menopause, having a family history, low body weight i.e. being small and thin, medical history, not getting enough calcium and Vitamin D, not eating enough fruits and vegetables, having a diet high in protein, sodium and caffeine, long-term sedentary lifestyle, smoking, excessive alcohol consumption, Hypogonadism and delayed puberty in males(2).

How prevalent is osteopenia?
As many people are unaware of their bone mineral density and with the lack of external symptoms, exact numbers of people with the condition are unknown. As a precursor to osteoporosis, an osteopenic individual is at a greater risk of developing osteoporosis later in life. Studies show that around 10 million Americans already have osteoporosis with a further 34 million at risk of developing it(3).The National Health Survey suggests that 692,000 Australians have doctor-diagnosed osteoporosis, but admit this is an underestimate(4). Studies in Australia show that one in two women and one in three men over the age of 60 will have an osteoporotic fracture(5). Only around 20% of people with osteoporotic fractures who come to medical attention are treated to prevent further bone loss and fractures.(5) It was estimated in 2005 that osteoporosis was responsible for an estimated two million fractures and $19 billion in costs. By 2025, experts are predicting that osteoporosis will be responsible for approximately three million fractures and $25.3 billion in costs each year(3). Studies show that 20% of seniors who break a hip will die within one year from problems related to the broken bone or from the surgery undertaken to repair the break. Many of those who survive require long-term care(5). Epidemiological studies suggest that regular exercise is associated with a reduction in osteoporotic fracture risk of up to 50% in men and women over 65 years of age(6).

What treatment options are available?
Treatment of osteopenia is not as simple as taking a population and prescribing an ailment designed to address a single common underlying cause. As per the risk factors, treatment needs to be individualised based on the unique underlying condition of each sufferer, it is important to slow down the progression before it turns into osteoporosis. Treatment options are very similar to those of osteoporosis, in particular, the most common treatment options are:

* Physical activity - Physical activity has shown to not only increase the density of bones directly involved in the activity being performed but also increasing bone density of those muscles indirectly involved(7) * Diet - Increasing calcium, vitamin D, fruits and vegetables, whilst reducing sodium, caffeine, alcohol and ensuring the diet is not too high in protein is an excellent start. Additionally studies have shown that a       a gluten free diet has a strong correlation with increasing bone density(8). * Additional lifestyle changes may include quitting smoking and increasing the skins exposure to the sun.
 * Increasing bone density through lifestyle changes

What are the exercise benefits on osteopenia?
Sustained exercise has many chronic benefits, some obvious such as weight loss and maintenance and others which may not be so obvious. Exercise has positive effects on osteopenia through increasing bone mineral density and the ability to effectively use and store calcium amongst others, but what exercise method is best?

Aerobic

Underlying causes and risk factors may limit the ability for osteopenics to commit to aerobic exercise or sustain it for a time period that is required to positively benefit. Building up to an exercise regime of walking at a moderate pace for an hour every day has long term benefits on increased bone mineral density(11) as long as it is sustained. Aerobic exercise has an overall positive effect on the general populous health and the health of bones as a whole(12).

Resistance

Resistance training has shown to have a more potent effect than aerobic exercise on bone density, in particular the site specific bones that the muscles which are being worked are attached to. Progressive resistance training, training where the resistance is increased with muscle adaptation, is commonly seen to be the most effective overall method to increase site specific bone mineral density(12).

As can be concluded from the above a mix of aerobic training and resistance training will yield the greatest positive benefits on bone mineral density and thus will be the most beneficial for osteopenics.

Recommendations, considerations and precautions
As co-morbidities may exist clearance from a medical professional should be provided before an individual undertakes any form of exercise. Clearance should take into account the severity of osteopenia (in known cases), associated risk factors, underlying conditions, current medications and co-morbidities for each patient. Once clearance is received the person should be closely monitored throughout all exercise routines ensuring that technique and intensity is individually catered. Exercises and activities that increase the chance of falling or have a collision aspect should be avoided in order to minimise the risks of an osteopenia related fracture or bone injury.