Osteopenia is a bone condition characterized by a decreased density of bone, which leads to bone weakening and an increased risk of breaking a bone (fracture). Osteopenia and osteoporosis are related conditions. In osteopenia, however, the bone loss is not as severe as in osteoporosis.
That means someone with osteopenia is more likely to fracture a bone than someone with a normal bone density but is less likely to fracture a bone than someone with osteoporosis.
Osteomalacia, osteomyelitis, and osteoarthritis are different conditions that are frequently confused with osteopenia because they sound similar. Osteomalacia is a disorder of the mineralization of newly formed bone, which causes the bone to be weak and more prone to fracture.
There are many causes of osteomalacia, including vitamin D deficiency and low blood phosphate levels. Osteomyelitis is bone infection. Osteoarthritis is joint inflammation featuring cartilage loss and is the most common type ofarthritis. Osteoarthritis does not cause osteopenia, osteoporosis, or a decreased bone mineral density.
Osteopenia has been described as a "silent" condition. There are no outward signs or symptoms, although certain risk factors and precursors can be identified.
Risk Factors which may influence loss of BMD (Bone Mineral Density)
Most cases of osteopenia are seen in post menopausal women, this is due to the influence of estrogen on bone cells (i.e. where estrogen levels are decreased osteoclasts have a prolonged lifespan so more mineral is deorbed than absorbed into the bone).
Women also generally have a lower peak BMD. Peak BMD is reached around the age of 30; as we age it steadily decreases. Other risk factors include: a personal or family history, low body weight, a sedentary lifestyle, diet, smoking and other medical conditions.
Individuals who exhibit such risk factors should consider screening for osteopenia/osteoporosis. The National Osteoporosis Foundation (5) lists the following as recommendations for undergoing DXA testing:
- Women: postmenopausal and under age 65 with risk factors for osteoporosis, over 65 whether or not there are risk factors present.
- Men: age 50-70 with risk factors for osteoporosis, over age 70 whether or not there are risk factors present.
- Anyone over age 50 after a bone break.
If a patient gets shorter with age, that often provokes a bone mineral density test.
Other reasons your doctor may give you a BMD test:
- Long-term use of certain medications including steroids for breast cancer, prostate cancer, aromatase inhibitors, cortisone, and hormone replacement therapy.
- Hyperthyroidism or Hyperparathyroidism.
- Frailty syndrome.
- Fracture or bone loss in spine.
- Chronic back pain that causes the doctor to suspect a fracture.
Prevalence of Osteopenia
Because there are no obvious symptoms of osteopenia, it is impossible to accurately predict how many people have this condition as many cases may go unreported. A study in 2007 stated that approximately 33.6 million adults were osteopenic in 2002; it went on to estimate that this figure may rise to 47.5 million by 2020.
Osteopenia has multiple causes.
Common causes include:
- genetics (familial predisposition to osteopenia or osteoporosis, as well as other genetic disorders);
- hormonal causes, including decreased estrogen (such as in women after menopause) or testosterone;
- excess alcohol;
- thin frame;
- certain medications (such as corticosteroids, including prednisone) and antiseizure medications;
- malabsorption due to conditions (such as celiac sprue);
- chronic inflammation due to medical conditions (such asrheumatoid arthritis).
People with osteopenia should make certain important lifestyle modifications and ensure that their dietary intake of calcium and vitamin D are adequate. Not everyone with osteopenia requires treatment with prescription bone-building medication. This is because while 34 million people have osteopenia, and therefore the condition accounts for a large number of bone fractures, the absolute risk for fracture in any individual is low.
So, if bone-building medications were prescribed to everyone with osteopenia, that would result in a large number of people who may never even have had a bone fracture taking medication for many years, exposing them to unnecessary expense and potential side effects.
If you have osteopenia, your doctor can determine if you need treatment with prescription medication. The decision to treat is made on a case-by-case basis, depending on each individual. Factors other than bone mineral density can increase the risk of fracture, and these risk factors can be used to determine if a certain individual requires treatment for osteopenia.
These include a parent who fractured their hip, previous or current treatment with corticosteroids (such as prednisone), thin and small-framed individuals, rheumatoid arthritis, smoking, and drinking more than two alcoholic beverages daily. Your doctor may use this information to calculate your risk of a bone fracture in the next 10 years. This risk can then be used to determine if treatment is necessary.
The diagnosis of osteopenia can be an eye-opening wake-up call to make certain lifestyle changes. Lifestyle modifications are an important part of the prevention and treatment of osteopenia and osteoporosis. These lifestyle changes include weight-bearing exercise (for example, walking or lifting weights), quitting smoking, not drinking excessively, and ensuring an adequate daily intake of calcium and vitamin D. If dietary intake is not adequate, then supplements may be prescribed. The Institute of Medicine released the following guidelines on calcium and vitamin D intake on Nov. 30, 2010:
- 800 IU (international units) daily for women over the age of 71.
- 600 IU daily for women in other age groups, men, and children.
- 400 IU daily for infants under 12 months of age.
- 1,200 mg (milligrams) daily for adult women over the age of 50 and men 71 years and older.
- 1,000 mg daily for younger adult women (who are not breastfeeding or lactating) and adult men.
The following prescription medications are treatment options for osteopenia and osteoporosis:
- Bisphosphonates (including alendronate [Fosamax], risedronate[Actonel], ibandronate [Boniva], and zoledronic acid [Reclast]).
- Calcitonin (Miacalcin, Fortical, Calcimar).
- Teriparatide (Forteo).
- Denosumab (Prolia).
- Hormone replacement therapy with estrogen and progesterone.
- Raloxifene (Evista).
Alendronate (Fosamax), risedronate (Actonel), zoledronic acid (Reclast), and raloxifene (Evista) have an indication from the Federal Drug Administration (FDA) for the prevention of osteoporosis, as well as for the treatment of osteoporosis. For raloxifene (Evista) and risedronate (Actonel), the doses used for osteopenia are the same as those used for osteoporosis.
Zoledronic acid (Reclast) is an intravenous medication given yearly for the treatment of osteoporosis but every other year for the prevention of osteoporosis. Alendronate (Fosamax) is given as 10 mg daily or 70 mg weekly for osteoporosis, and the dose is halved for the prevention of osteoporosis (5 mg daily or 35 mg weekly).