Osteoporosis  

What is osteoporosis?

Osteoporosis is a condition that causes your bones to weaken, making broken bones more likely.

What are the symptoms?

Osteoporosis is sometimes called the "silent disease". Most people affected are unaware that their bones are thinning until they break one.
Hip and wrist fractures are the most common breakages, but they can occur in any bone. Osteoporosis can result in small fractures in the bones of your spine, causing a loss of height and a curved back (sometimes known as "dowager's hump"). This can lead to long-lasting neck and back pain.

What causes osteoporosis?

Healthy bone consists of a strong mesh made of protein and minerals (particularly calcium). This mesh is living tissue that is constantly being renewed in a process called bone turnover. Old, worn out bone is broken down and absorbed by the body while, at the same time, new bone tissue is created from fresh protein and minerals.

In children and young people, more new bone is created than is broken down. This makes bones bigger and more dense.

Bones are at their strongest when peak bone mass is reached, which usually happens in your mid-twenties. This is maintained for about ten years, with roughly equal amounts of bone creation and breakdown. After the age of about 35, bone loss begins to overtake creation as part of the normal ageing process. If you have osteoporosis, this process happens much more quickly, making your bones become weaker and more prone to fracture.

Who gets osteoporosis?

Some people are more likely to develop the disease than others. The strongest risk factors are listed below.

• You are more likely to get osteoporosis if you are aged over 60 years. The risk continues to rise as you get older.

• Women are more likely to develop it, as they have smaller bones and less total bone mass. Women also lose bone more quickly after the menopause 

• You are more likely to develop the condition if you have a family history of osteoporosis.

Low levels of oestrogen

The hormone oestrogen reduces the amount of bone that is broken down and so helps to protect against osteoporosis. In women, the ovaries make oestrogen from puberty to the menopause. Any condition that reduces the number of years that a woman produces oestrogen tends to increase the risk of osteoporosis.

This includes:

• having an early menopause (before the age of 45)

• having an early hysterectomy (before the age of 45, especially if both ovaries are removed)

• missing periods for one year or more (when not pregnant) - this can happen as a result of over-exercising or over-dieting

Other risk factors

Men who have lower than normal levels of the hormone testosterone (hypogonadism) have a greater risk of osteoporosis.

For both men and women, the following factors also increase the risk of developing the disease:

• long-term immobility
• smoking and drinking alcohol excessively
• very low body mass index (a way of combining weight and height measurements)
• low levels of vitamin D
• low levels of dietary calcium
• digestive disorders that affect nutrient absorption such as inflammatory bowel disease, liver disease or coeliac disease
• long-term use of corticosteroid tablets (medicines sometimes used to treat severe allergies or inflammation)
• thyroid disorders
• some other disorders including kidney disease and rheumatoid arthritis

Can I prevent osteoporosis?

You may be able to reduce the chances of getting the disease by making changes to the way you live your life. A healthy diet and exercise can increase bone mass and reduce the risk of developing osteoporosis, especially in young people with growing bones.

Exercise
Low-impact exercises where you support your own weight are best for strengthening bones. The National Osteoporosis Society recommends running, aerobics, tennis, weight-training and brisk walking. Ideally, try to do this type of activity for at least 30 minutes a day - this will also help to keep your heart healthy. 

If you are not used to exercising, build up your exercise routine gradually, increasing frequency before intensity. Talk to your GP before you start if you have a health problem that affects your heart or breathing.

Diet
Eating a diet rich in calcium is important for maintaining healthy bones. Good sources of calcium include milk and dairy products, such as hard cheese and yogurt, and some green leafy vegetables and fruit. Your body also needs vitamin D to absorb calcium properly. Vitamin D is found in certain foods, including cod liver oil, sardines and tuna, as well as milk and eggs. It is also generated by your skin when you are in the sunlight, although care must be taken because exposure to the sun is known to cause skin cancer. Only brief, casual, sunlight exposure is needed.

Lifestyle
Smoking can have a harmful effect on your bone strength and can also cause an early menopause. If you smoke, try to give up. You should also be careful not to drink too much alcohol.

Treatment for osteoporosis

There are now a number of effective treatments that can help prevent fractures and increase bone density. Some examples are listed below.

• Vitamin D and calcium intake is an effective treatment to reduce bone loss in the elderly. Post menopausal women should aim to take around 700 to 1000mg of calcium a day, either in their diet or as a supplement.

• Exercising appears to reduce the risk of fractures in the elderly. As for prevention of the disease, exercises where you take your own weight are recommended.

In severe cases you may need to consult your GP and consider taking stronger products. Take care when deciding the way forward and always discuss the potential side-effects before taking the medicine.  

Products which you may consider include:

• Bisphosphonates are non-hormonal medicines which work by blocking the break down of bone. There are four bisphosphonates available in the UK - alendronate (Fosamax), etidronate (Didronel), risedronate (Actonel) and ibandronate (Bonviva).

• Strontium ranelate (Protelos) is a drug which stimulates new bone formation, and is used if you do not tolerate bisphosphonates well.

• Selective oestrogen-receptor modulator (SERM) is a synthetic hormone replacement which works by copying the effects of oestrogen on the bones. This type of drug reduces the risk of osteoporosis and heart disease, but appears not to increase the risk of breast or endometrial cancers. However, it only appears to prevent fractures in the spine. The SERM currently available in the UK for osteoporosis is raloxifene (Evista).

• Calcitonin is a hormone made by the thyroid gland (a hormone-producing gland in the neck), which blocks the action of the cells that break down bone. It is taken by spraying it into your nose.

Hormone replacement therapy (HRT)

HRT is a prescription-only treatment that aims to restore hormones to a pre-menopausal level. It is taken to relieve menopausal symptoms such as hot flushes, night sweats, and vaginal dryness. HRT has also been shown to reduce osteoporosis, but it is no longer prescribed to treat or prevent it. This is because taking it over a number of years increases the risk of stroke, blood clots in the veins, cancer in the lining of the womb, and breast cancer. It is now only prescribed for the shortest time needed to treat menopausal symptoms. Deciding whether to take HRT is your choice and your doctor will discuss the risks and benefits with you.