With osteoporosis, bones are more likely to fracture or break. A minor fall or injury that would not usually cause a fracture can do damage. Although the spine, hips and wrists are most commonly injured, fractures can occur almost anywhere. Osteoporosis often takes decades to develop. Unfortunately, there are usually no symptoms until a bone breaks.

What causes it?

There is no one cause of osteoporosis. We build bone strength during childhood and the early adult years. After age 30 or 40, we start to lose some bone density. Osteoporosis is more likely if you did not reach ideal bone thickness during your childhood and teenage years.

Women who no longer menstruate lose bone density more quickly, since they have less of the female hormone estrogen. This hormone helps cells that form bone to keep working. When estrogen levels drop off after menopause, so do bone density levels.

In men, the male hormone testosterone protects against bone loss. Osteoporosis in men generally occurs after the age of 65, when testosterone production is lower and there is less active testosterone available.

Lifestyle definitely plays a role. A lack of calcium and Vitamin D in the diet contributes to bone thinning or osteoporosis. Cigarette smoking, too much alcohol (more than two glasses of alcohol per day) and caffeine (more than two or three cups of coffee or tea per day) can also make bones thinner. Those who do not get much exercise are at risk, as weight-bearing exercise builds strong bones. Being inactive or bedridden for significant lengths of time also makes osteoporosis more likely. Family history is important. A tendency toward low bone mass can pass from parent to child.

Some medications weaken bone, especially when used for long periods of time. Using steroid medicines such as prednisone longer than three months, injected blood thinners such as heparin longer than six months, and seizure medications such as Dilantin™ longer than ten years increases the risk.
Certain illnesses are linked with osteoporosis. They include rheumatoid arthritis, overactive thyroid or parathyroid glands, and inflammatory bowel disease such as Crohn’s disease or ulcerative colitis. Being underweight for any reason can also cause problems.

How is osteoporosis diagnosed?

A type of x-ray test called a bone density scan is now available. This test assesses whether someone has:

normal bone density (bones that are no less likely to break)
osteopenia (thinner bones than normal, ranging between normal density and osteoporosis), or osteoporosis (bones with a significantly increased risk of fracture).
A bone density scan can detect osteoporosis in patients more accurately than simple x-rays, before fractures occur.

Other resources

Exercise and Osteoporosis
Osteoporosis Canada: www.osteoporosis.ca

How is osteoporosis treated?

Diet and lifestyle measures are the main ways to treat osteoporosis. If you have osteoporosis, be sure to take in enough calcium and vitamin D through diet and supplements. Regular activity makes bones stronger, especially low-impact exercise supporting your own weight. As smoking or drinking too much alcohol weakens bone, consider quitting.

A variety of medications can treat osteoporosis. A class of drugs called the bisphosphonates can help strengthen bones. Specific medications include Didrocal™ (etidronate disodium and calcium carbonate), Fosamax™ (alendronate), and Actonel™ (risedronate).

Bisphosphonates work by affecting the cells that modify our bones. Bones are constantly under construction. Cells called osteoblasts produce new bone, while osteoclasts remove old bone. Bisphosphonates slow bone removal, shifting the balance of cell activity so more bone is produced.

Most people take bisphosphonates by mouth. However, they are sometimes given as an intravenous (IV) injection, going directly through a needle into the blood stream. For instance, this method is used to treat certain types of bone cancer. The IV drugs include Aredia™ (pamidronate) and Zometa™ (zoledronic acid).

Are medications for osteoporosis safe?

Recently, articles in the media and on the internet have expressed concern about the safety of these medications. Unfortunately some of these reports have not relayed all of the facts about complications accurately nor put the issue in proper perspective. As a result many people are worried that the risks of taking these medications outweigh the potential benefits and wonder what they should do. Some patients ask their family doctors about the risks of taking medication to treat osteoporosis. Others have decided on their own to stop taking it, The fact that while there could be concerns for some, most users of this medication are not at risk.

The biggest concern involves osteonecrosis of the jaw (ONJ), a rare but serious condition. In this serious condition, dead bone develops in either the upper or lower jaw. It is not easily treated with medications or surgery, and can also be more at risk for bone infection. ONJ seems to develop most commonly after dental surgery in a small number of patients taking bisphosphonate medications.

What do we know about ONJ?

Although the actual rate of ONJ occurrence is not known, it is thought to be rare.

While bisphosphonate medications have been taken by millions of patients, ONJ has only been reported in a few hundred.
Sixty per cent of those who developed ONJ did so after dental surgery or removal of a tooth.
Most patients who developed ONJ (85 per cent) had a form of cancer, usually either myeloma (a form of bone marrow cancer) or breast cancer that had spread to the bone.
Only four per cent were taking bisphosphonates by mouth.
Most of those with ONJ (94 per cent) were using the IV or injectable form of the medication. Usually, bone cancer was being treated rather than osteoporosis. Doses of the IV bisphosphonates are much higher when used to treat cancer as compared to treating osteoporosis.

As you can see, ONJ is a relatively rare, but serious, possible complication of taking osteoporosis medication. Those taking high doses of bisphosphonate medications to treat cancer are more at risk of ONJ. If this is true for you, take the following precautions:

Any invasive dental work, such as having a root canal or tooth pulled, should be done before starting bisphosphonate therapy.
A dentist should treat any existing dental infections.
If possible, those at high risk for ONJ should avoid dental procedures while on bisphosphonates.
Have poorly fitting dentures adjusted to be sure that there is no friction or damage to the gums. This will help to prevent a gum infection that could cause more serious problems.
Take the best possible care of your teeth and mouth. Make and keep any appointments advised by your dentist and dental hygienist.
It is not necessary to postpone non-invasive dental work, such as dental hygiene and replacement of surface fillings.

Making a decision about medications

Bisphosphonate medications are generally very safe and effective in treating osteoporosis. If you are healthy and do not have cancer, and take bisphosphonate medication orally, your chance of developing ONJ is extremely rare. If you are concerned about ONJ, talk to your doctor about it before you stop taking the medication. Everyone’s situation is unique. Review the reasons for your treatment and decide whether the benefits outweigh the risks. Your dentist can advise whether you have any dental conditions that should be treated to reduce your risk of ONJ.

Understanding Osteoporosis How it's diagnosed and treated

Why is osteoporosis a problem?