Osteoporosis is a disorder where the bones become weakened by loss of substance (osteopenia), leading to an increased risk of broken bones (fractures) with minimal trauma.
The thinning of the bones does not, in itself, cause much in the way of symptoms. It does, however, lead to a risk of broken bones without much of an injury. In fact the bones of the spine can sometimes collapse without any obvious cause.
When the bones are significantly thinned (low in bone mass) people who fall are more likely to break their wrist, hip, or other bones. A cough or a sneeze is more likely to cause a fracture of a rib or the partial collapse of one of the bones of the spine (vertebra). Any bone is more at risk with osteoporosis.
Osteoporosis affects people in a number of ways:
- Pain. The broken bones (fractures), which can happen without any obvious cause, can lead to severe pain that lasts for quite a number of weeks.
- Financial. People (especially the elderly) who develop a fracture become more dependent on others to look after them. It may result in an independent person needing long term support at home, or even having to go into a nursing home.
- Mortality. With a 20% increase in mortality in the first year after a broken hip, the mortality is greater than that of cancer of the neck of the womb (cervix).
- The collapse of vertebrae leads to increased curvature of the spine and loss of height.
Bone is constantly being replaced. Old bone is reabsorbed and new bone laid down all the time. This results in about 10% of the bone in your body being replaced every year. When more bone is reabsorbed than is laid down, this results in thinning of the bones (loss of bone mass).
The substance of the bones (bone mass) builds up to a peak at about 30 years of age. After that we lose bone mass by about 1% each year.
When the menstrual periods stop in women (the menopause) there is a phase, for a few years, when women lose bone mass at a faster rate.
There are a number of types of primary osteoporosis:
- Type I (postmenopausal). This seems to be caused by deficiency of the female hormone, oestrogen.
- Type II ("senile" or age-related).
- Idiopathic (no specific cause identified). This affects people in the younger age groups, that is less than 50 years.
There is also secondary osteoporosis, which is connected with the following factors:
- Hormonal or endocrine. This includes overactive thyroid, underproduction of the sex hormones and excessive natural production of steroids.
- Digestive, or gastrointestinal. This includes:
- conditions which lead to poor absorption of the nutrients in the food we eat (malabsorption), such as sensitivity to gluten (Coeliac Disease);
- operations that lead to faster transit of food through the digestive system;
- disease of the liver.
- Arthritis and joint disease.
- Cancer and malignant disease.
- Certain medications, for example steroids.
Osteoporosis can occur in anybody, but certain factors add together to increase the risk of a person developing osteoporosis.
If you fall into one or more of these groups you may be at greater risk of osteoporosis:
- Older age group
- Menopause before the age of 45
- Low sex hormone levels. This can be associated with excessive weight loss (as in anorexia nervosa) and excessive exercise. Both of these are sometimes linked, for example in ballerinas.
- High alcohol intake
- Physical inactivity or bed rest
- Thin people
- Family history of osteoporosis
If you already have a fracture or bone collapse, then this will point towards the possibility of osteoporosis. Other factors that may alert the doctor to the possibility include:
- back pain
- loss of height
Tests are likely to include Dual energy X-ray absorptiometry (DXA or DEXA scan). Your doctor may want to follow up any possible causes for the osteoporosis, if the bone density does turn out to be lower than would normally be expected for your age and sex.
There are a number of treatments available:
- Bisphosphonates. This type of medication is used to arrest the progress of osteoporosis and even reverse it. They encourage the laying down of calcium in the bones. One of these is also used when people have to be on long term steroids.
- Strontium ranelate (Protelos or Protos) is sometimes used if bisphosphonates cannot be taken.
- Calcitonin. This is a hormone which used to be given, by injection, for a limited period of weeks, but is now available as a nasal spray, which is used long term.
- Calcium. Ensure that you have enough in your diet, but your doctor may well also want you to take a supplement. The chewable or effervescent forms are absorbed better by the body than straight tablets.
- Vitamin D and calcium preparations are sometimes helpful, particularly in the elderly.
- Fluoride is used in some countries, as it does appear to increase bone mass, but there does not appear to be strong evidence that it prevents fractures.
- Pain relief. You may need quite strong pain killers (analgesics), for quite some time, in the event of an osteoporotic fracture.
- Hormone replacement therapy is no longer recommended for osteoporosis as the risks are thought to outweigh the benefits.
Your doctor may send you to a specialist. You are likely to have follow-up tests of bone density, to monitor progress while on treatment.
- Continue regular, weight bearing exercise.
- Ensure adequate dietary calcium.
- If you are on long term steroids, it is worth checking that your doctor has considered taking action to avoid osteoporosis.
- Cut down alcohol intake.
- Stop smoking.