Glucocorticoid-Induced Osteoporosis

Glucocorticoid medications have both direct and indirect effects on bone tissue that lead to bone loss. These drugs have a direct negative effect on bone cells, resulting in a reduced rate of forming new bone. Also, they can interfere with the body's handling of calcium and affect levels of sex hormones. Either of these problems can lead to increased bone loss.

Anyone who is taking glucocorticoid medications and has other risk factors for osteoporosis increases their risk of developing glucocorticoid-induced osteoporosis and breaking a bone (fracture). You can change some of these risk factors, but not others.

Major risk factors that you cannot change include:

• Older age (children are at risk too)
• Non-Hispanic white or Asian ethnic background
• Small bone structure
• Family history of osteoporosis or osteoporosis -related fracture in a parent or sibling
• Prior fracture due to a low-level injury, particularly after age 50

Risk factors that you may be able to change include:

• Low levels of sex hormone, mainly estrogen in women (e.g., menopause) and men
• The eating disorder anorexia nervosa
• Cigarette smoking
• Alcohol abuse
• Low calcium and vitamin D, by low dietary intake or poor absorption in your gut
• Sedentary (inactive) lifestyle or immobility
• Certain medications besides glucocorticoids, including the following:
  • Excess thyroid hormone replacement
  • The blood thinner heparin
  • Some treatments of breast cancer (Arimidex, Femara, etc.) or prostate cancer (e.g., Lupron) that deplete sex hormones
• A disease that can affect bones
• Endocrine (hormone) diseases (hyperthyroidism, hyperparathyroidism, Cushing's disease, etc.)
• Inflammatory arthritis (rheumatoid arthritis, ankylosing spondylitis, etc.)

You can learn if you have osteoporosis by having a simple test that measures bone mineral density - sometimes called BMD. BMD - the amount of bone you have in a given area - is measured at different parts of your body. Often the measurements are at your spine and your hip, including a part of the hip called the femoral neck, at the top of the thigh bone (femur). Dual energy X-ray absorptiometry (referred to as DXA and pronounced “dex-uh”) is the best current test to measure BMD.

The test is quick and painless. It is similar to an X-ray but uses much less radiation. Even so, pregnant women should not have this test, to avoid any risk of harming the fetus.

DXA test results are scored compared with the BMD of young, healthy people. This information results in a measure called a T-score. The scoring is as follows:

The risk of fracture most often is lower in people with osteopenia than those with Osteoporosis. But, if bone loss continues, the risk of fracture increases. Yet, people taking glucocorticoids seem to be at an increased risk of fracture at higher bone densities than would be expected.

As doctors who are experts in diagnosing and treating diseases of the joints, muscles and bones, rheumatology providers can help find the cause of osteoporosis. They can provide and monitor the best treatments for this condition.

Anyone taking glucocorticoid medicine must get enough calcium and vitamin D. The American College of Rheumatology recommends you should take at least 1,200 mg of calcium and 800 to 1,000 International Units (called IU) of vitamin D supplements each day. Your doctor may measure the vitamin D level in your blood to find out if you need more vitamin D supplementation.

Some people also will need medication. The decision to start prescription medications will depend on your other risk factors, the dose of glucocorticoid medication you are taking and how long you may be on it, as well as your BMD results by DXA.

The US Food and Drug Administration (better known as the FDA) has approved certain drugs to prevent and treat glucocorticoid-induced osteoporosis. In a drug class called bisphosphonates, alendronate (Fosamax), risedronate (Actonel), and zoledronic acid (Reclast) are FDA approved for both the prevention and treatment of glucocorticoid-induced osteoporosis. Teriparatide (Forteo), a different type of drug, also is approved for treatment of glucocorticoid-induced osteoporosis. This manmade form of parathyroid hormone helps stimulate bone formation.

Women planning a pregnancy should talk to their doctor about the pros and cons of using a bisphosphonate or teriparatide. None of the prescription drugs for managing osteoporosis has enough safety data available to recommend using them in women who are pregnant or breastfeeding.

If you take glucocorticoid medicine for any length of time, you should start taking calcium and vitamin D supplements at the doses recommended in the prior section. Work with your health care provider to help use the smallest dose of glucocorticoid for the shortest duration possible that will still keep your disease under control.

Patients taking glucocorticoid medicine should:

• Be physically active and do weight-bearing exercises, like walking, most days each week.
• Change lifestyle choices that raise your risk of osteoporosis, such as quitting smoking.
• Implement strategies to help decrease your risk of falling, which raises the risk of fractures.
• Get DXA testing of your BMD.

If you have low bone density and a high risk of breaking a bone, your health care provider may suggest medicine to prevent your bones from getting weaker. Health care providers now have a tool for estimating the risk of a patient having an osteoporotic fracture in the next ten years. This fracture risk assessment tool from the World Health Organization is called FRAX. It can help guide treatment decisions.

The most serious health consequence of any type of osteoporosis is a fracture. Spine and hip fractures especially may lead to chronic pain, long-term disability and even death. The main goal of treating glucocorticoid-induced osteoporosis is to prevent fractures.