Osteoporosis is a progressive disorder defined by loss of bone mass and density, which leads to an increased risk for fractures. The term literally means “porous bone.”
Osteoporosis is a disorder of the skeleton in which bone strength is abnormally weak. This leads to an increase in the risk of breaking bones (bone fracture). In the United States, more than 10 million people have osteoporosis of the hip and almost 19 million more have low hip bone density. Between 4 to 6 million postmenopausal white women have osteoporosis, and an additional 13 to 17 million have low hipbone density. One in two white women will experience a bone fracture due to osteoporosis in her lifetime. In 1993, the United States incurred an estimated loss of 10 billion dollars due to loss of productivity and health care costs related to osteoporosis. With the aging of America, the number of people with osteoporosis related fractures will increase exponentially. The pain, suffering, and economic costs will be enormous.
What Are the Risk Factors for Osteoporosis?
Important risk factors for osteoporosis include:
- Age. After maximum bone density and strength is reached (generally around age 30), bone mass begins to decline naturally with age.
- Gender. Women over the age of 50 have the greatest risk of developing osteoporosis. In fact, women are four times more likely than men to develop it. Women’s lighter, thinner bones and longer life spans are part of the reason they have a higher risk.
- Ethnicity. Research has shown that Caucasian and Asian women are more likely to develop osteoporosis. Additionally, hip fractures are twice as likely to occur in Caucasian women as in African-American women. However, women of color who fracture their hips have a higher death rate.
- Bone structure and body weight. Petite and thin women have a greater risk of developing osteoporosis. One reason is that they have less bone to lose than women with more body weight and larger frames. Similarly, small-boned, thin men are at greater risk than men with larger frames and more body weight.
- Family history. Heredity is one of the most important risk factors for osteoporosis. If your parents or grandparents have had any signs of osteoporosis, such as a fractured hip after a minor fall, you may be at greater risk of developing the disease.
- Prior history of broken bones.
- Cigarette smoking. Smoking puts you at higher risk of having osteoporosis and fractures.
- Alcohol. Heavy alcohol use can lead to thinning of the bones and increase your risk of fracture.
- Certain Diseases. Some diseases such as rheumatoid arthritis increase the risk for osteoporosis.
- Certain medications. The use of some medications — for example, the long term use of steroids such as prednisone — can also increase your risk of developing osteoporosis.
Risk Factors You Can Change
There are other risk factors for osteoporosis that can be changed.
- Poor diet. Getting too little calcium over your lifetime can increase your risk for osteoporosis. Not getting enough vitamin D either from your diet, supplements, or sunlight can also increase your risk for osteoporosis. Vitamin D is important because it helps the body absorb calcium. An overall diet adequate in protein and other vitamins and minerals is also essential for bone health.
- Physical inactivity. Not exercising and being inactive or staying in bed for long periods can increase your risk of developing osteoporosis. Like muscles, bones become stronger with exercise.
- Smoking. Cigarette smokers may absorb less calcium from their diets. In addition, women who smoke have lower levels of estrogen in their bodies.
- Medications. Some commonly used medicines can cause loss of bone mass. These include a type of steroid called glucocorticoids, which are used to control diseases such as arthritis and asthma; some antiseizure drugs; some medicines that treat endometriosis; and some cancer drugs. Using too much thyroid hormone for an underactive thyroid can also be a problem. Talk to your doctor about the medications you are taking and what you can do to protect your bones.
- Low body weight. Women who are thin and small-boned are at greater risk for osteoporosis.
Are there any other risk factors?
Some risk factors cannot be changed but it’s important to know about them as some research suggests they make it much more likely you will have fragile bones and fractures in later life. It’s important to understand that, often, osteoporosis and fractures aren’t caused by something you have ‘done’ or could have changed. Their cause may just be part of your genetic makeup or, like many medical conditions, something that happens but where we don’t fully understand why.
Genes: our genes determine our risk of osteoporosis to a large extent although there isn’t a simple genetic test for osteoporosis. Research has shown that if one of your parents had a broken hip you are more likely to have a fragility fracture yourself.
Age: bone loss increases in later life, so by the age of 75 years about half of the UK population will have osteoporosis as measured on a bonedensity scan. As you get older, bones become more fragile and generally more likely to break, whatever your bone density as measured on a scan. This is partly because of generally reduced bone strength but also the result of an increased risk of falling as we get older.
Gender: osteoporosis and fractures are more common in women than men. Women tend to live longer, which makes fractures more likely, but in each age group the fracture risk is higher. Men have bigger bones, and bone size in itself seems to protect against fracture. In addition, at around the age of 50, women experience the menopause, at which point their ovaries almost stop producing the sex hormone oestrogen, which helps to keep bones strong.
Race: Afro-Caribbean people are at a lower risk of osteoporosis and fractures than those of Caucasian or Asian origin because their bones are bigger and stronger.
Previous fractures: if you have already broken bones easily, including in the spine, you are much more likely to have fractures in the future – having already broken bones easily is one of the most obvious indicators that your bones are fragile. In fact, research has shown that after one fragility fracture you are two to three times more likely to have another.
What medicines increase my risk?
Some medications (see below) are linked with an increased risk of osteoporosis and/or fractures. Once you know about these, you can discuss with your doctor the ways to limit their effects. Your doctor may review your medicines and possibly change the dose or even the drug (don’t make any changes without talking to your doctor first). Sometimes an osteoporosis drug or a supplement can be prescribed to help protect your bones from the effect of these medicines. However, if you are only taking the drug at a low dose or for a limited period, your doctor may be able to reassure you the effect on your bones is insignificant.
- glucocorticoid (‘steroids’) tablets for other medical conditions for over three months
- anti-epileptic drugs
- breast cancer treatments such as aromatase inhibitors
- prostate cancer drugs that affect either the production of the male hormone testosterone or the way it works in the body.
Other medicines may increase risk, but more research is needed:
- drugs to reduce inflammation of the stomach and oesophagus, called proton pump inhibitors (PPIs)
- diabetic drugs in the glitazone group, including pioglitazone
- injectable progestogen contraceptives such as medroxyprogesterone acetate, known as Depo Provera
- some drugs used for mental health problems such as tricyclic antidepressants and particularly selective serotonin reuptake inhibitors (SSRIs).