Osteoporosis - what you need to know

Osteoporosis is a degenerative bone disease that leads to the increased risk of breaks or fractures. Although some people are more prone to it because of family history or from smoking, there are a number of things that can be done to prevent the onset of this disease.

One of the most troubling things about osteoporosis is that people generally don't know they have it until their bones start breaking. While at this point the disease can be managed, there's nothing that can be done to reverse it completely. So, although osteoporosis is considered to be a disease affecting elderly people, young people should be aware that it is their behaviour and lifestyle while they are young that will prevent or delay its onset, as there is no complete treatment for osteoporosis - making early detection so important. Of course, with osteoporosis, prevention is definitely better than cure.

World Osteoporosis Day takes place every year on 20 October. This year's theme is "Love your bones" and focuses on the three steps to unbreakable bones: Vitamin D, Calcium-rich foods and exercise.

Exercise

Studies have shown that moderate to high intensity weight-bearing aerobic exercise, resistance training like lifting weights and high impact exercise like jumping or rope skipping increase bone mineral density (BMD) by 1% to 4% in pre- and postmenopausal women according to the International Osteoporosis Foundation.

It is clear that being physically active reduces the risk of BMD loss and of hip, upper arm and vertebral fracture at an older age. It is particularly important for children and adolescents to exercise as this helps to develop stronger bones. In the elderly, even once osteoporosis has developed, the right kind of exercise can increase BMD and reduce the risk of falling and fractures.

Calcium

The focus in fracture prevention has shifted to a calcium-rich diet in conjunction with calcium supplementation. This is because calcium, which is needed for muscle contraction and is the building block of bone, is found in foods that contain other nutrients that are also valuable for bone and muscle health - especially protein.

Calcium-rich foods include all dairy products, fish, nuts, eggs, tofu, kidney beans and lentils. However, even by eating a diet rich in these foods, it can be difficult for most people to gain the recommended 800mg to 1 000mg of elemental calcium a day (this can increase to 2 000mg during pregnancy and lactation), so supplementation could be necessary. It is also very important that this is taken in conjunction with a Vitamin D supplement.

Vitamin D

Many people think that as long as they are getting enough calcium, they are doing everything that they can to reduce the risk of osteoporosis. However, there is increasing focus on Vitamin D as the vital supplement that helps to combat the loss of BMD. Vitamin D assists in calcium absorption, reduces bone loss, ensures correct renewal and mineralisation of bone and has a direct stimulatory effect on muscle, which reduces the risk of falling.

The main source of Vitamin D is sunlight, but this is not a reliable source of the vitamin. Although South Africans live in a sunny country, to make 800 IU (the recommended daily intake) of Vitamin D, a person needs to spend 30 minutes to an hour with face and hands fully exposed to midday sun - which in itself is problematic due to the increased risk of skin cancer. In some locations around the world, up to 20 hours of exposure to winter sunlight - obviously not possible to achieve - is required. Vitamin D is also found in fatty fish, but a person would need to eat two helpings of fatty fish a day to achieve an intake of 800 IU of Vitamin D.

As a result of Vitamin D's scarcity in nature and diet alone, a supplement of 800 to 1000 IU a day is recommended for those at risk of osteoporosis or in everyone over the age of 60.

For more information or to find out what you can do to raise awareness about osteoporosis, go to www.worldosteoporosisday.org and www.osteoporosis.org.za.

Osteoporosis fact box

What is osteoporosis?

Osteoporosis is a condition in which bone density decreases leading to frequent fractures.

What are the symptoms of osteoporosis?

The condition can be present for many years without any symptoms until a bone fractures. Even some osteoporotic fractures may not be detected because they do not cause symptoms. The most common symptom, however, is pain at the site of the fracture. Vertebral fractures can cause bands of pain from the back to the sides of the body, and can ultimately cause a loss of height and curvature of the spine. Stress fractures can occur as the result of minimal activity, like walking. Hip fractures most commonly occur as the result of a fall and then heal poorly because the bone is already compromised.

What causes osteoporosis?

Osteoporosis is caused by estrogen deficiency in women, which accelerates after menopause. It is also more likely to occur in women who stop menstruating as the result of intensive sporting activity or anorexia. Women who have both ovaries removed are also more likely to suffer from the condition.

Osteoporosis in men is caused by low testosterone levels.

Additional important causes of osteoporosis include hormonal disorders, certain malignant diseases, certain malabsorption diseases of the gut, and long-term intake of drugs like cortisone.

How is osteoporosis diagnosed?

A normal X-ray can pick up osteoporosis once at least 30% bone density has been lost. Instead, it is recommended that anyone at risk of osteoporis goes for a dual-energy X-ray obsorptiometry scan (DXA), which measures the bone density of the hip and spine in five to fifteen minutes, quite precisely.

All high-risk patients should speak to their doctors about going for scans, and women over 65 and men over 70 should go routinely. Risk assessment is the key to management of this condition.

How is osteoporosis treated?

Osteoporosis is treated by attempting to prevent bone fractures by reducing bone density loss or preferably by increasing bone density and strength. Exercise, quitting smoking and limiting alcohol are important factors in maintaining bone density.

Estrogen hormone therapy after menopause has been shown to prevent bone loss, increase bone density and prevent bone fractures. Other medications including bisphosphonates and selective estrogen receptor modulators (SERMs) have proven very effective at slowing the loss of bone density by decreasing the loss of calcium from the bones.

Who is affected by osteoporosis?

Osteoporosis is estimated to affect 200 million women worldwide. One in three women over fifty will experience an osteoporotic fracture, as will one in five men. While men are less likely to suffer an osteoporotic fracture, they are more likely to die as the result of one.

In South Africa, the condition is estimated to affect one in every four post-menopausal white women, but is significantly less prevalent in the black population.

High-risk individuals are those who have already had a scan that has indicated that they may be at risk of osteoporosis, any woman who has reached menopause before the age of 45, anyone with a family history of osteoporosis, women with slight builds and small frames, smokers, people who consume more than three units of alcohol per day and those who have poor nutrition.