Osteoporosis

Osteoporosis is a common bone disease that affects both men and women, usually as they grow older. Risk factors include not only age but also other diseases and even medications. One can take steps to reduce their risk of developing osteoporosis and avoid the often-debilitating complication of bone fractures that can result from this disease. Once a diagnosis of osteoporosis is made medications can slow and even stop the progression of bone loss.

Osteoporosis is a condition of weak bone caused by a loss of bone

mass as well as a change in bone structure. The first picture is

normal bone and the second shows osteoporotic bone.

 

Osteoporosis is a silent disease of the bones, making them weak and prone to fracture. Bone is living tissue in a constant state of regeneration. Old bone is removed (bone resorption) and replaced by new bone (bone formation). By their mid-30s, most people begin to gradually lose bone strength as the balance between bone resorption and bone formation shifts, so that more bone is lost than can be replaced. As a result, bones become thinner and structurally weaker.

Osteoporosis has no associated symptoms, however the condition may come to attention with a bone fracture. With osteoporosis and weakned bone, fractures can occur with even minor trauma, such as a fall. The most common fractures occur at the spine, wrist and hip. Spine and hip fractures in particular may lead to chronic pain, long-term disability and even death. The goal of treating osteoporosis is to prevent such fractures.

Risk Factors for Osteoporosis

Some risk factors are modifiable, while others are not. Recognizing one’s own risk factors is important to take steps in preventing osteoporosis, or preventing progression and risk for bone fracture.

Major risk factors include:.

  • Older age (starting in the mid-30s but accelerating after 50)
  • Non-Hispanic white and Asian ethnic background
  • Small bone structure
  • Family history of osteoporosis or osteoporosis-related fracture in a parent or sibling
  • Previous fracture following a low-level trauma, especially after age 50
  • Sex hormone deficiency, particularly estrogen deficiency, both in women (e.g. menopause) and men
  • Anorexia nervosa
  • Cigarette smoking
  • Alcohol abuse
  • Low dietary intake or absorption of calcium and vitamin D
  • Sedentary lifestyle or immobility
  • Medications: glucocorticoid medications such as prednisone; excess thyroid hormone replacement; the blood thinner heparin; certain anti-convulsant medications such as phenytoin and ethotoin, etc.
  • Certain diseases can affect bone, such as endocrine disorders (hyperthyroidism, hyperparathyroidism, Cushing’s disease, etc.) and inflammatory disorders (rheumatoid arthritis, ankylosing spondylitis, etc.)

Who Develops Osteoporosis

Osteoporosis is more common in older individuals and non-Hispanic white women. But it can occur at any age, in both men and women, and in all ethnic groups.

In the U.S. about 8 million women and 2 million men have osteoporosis. Those over the age of 50 are at greatest risk of developing osteoporosis and suffering related fractures. In this age group, one in two women and one in six men, will suffer an osteoporosis-related fracture at some point in their lifetime. Non-Hispanic whites and Asians are most likely to experience osteoporosis and osteoporosis-related fractures. Hispanic and Non-Hispanic blacks can also develop osteoporosis and related fractures, but are at lower risk when compared to non-Hispanic whites and Asians.

Diagnosis

A dual energy x-ray absorptiometry (DEXA) study measures bone mineral density (BMD) at different sites such as the lower spine and hip and can help diagnose osteoporosis.

The results of the DEXA study are scored in comparison to the BMD of young, healthy individuals. The results are presented as the T-score. A T-score of -2.5 or lower is diagnostic of osteoporosis and at high risk for fracture. T-scores between -1.0 and -2.5 are generally considered to show decreased BMD or osteopenia. The risk of fractures is generally lower in people with osteopenia when compared with those with osteoporosis.

Treatment

Maintain bone health:

  • Ensure adequate calcium intake (1000 mg per day for women before menopause and 1500 mg per day for postmenopausal women who are not taking estrogen replacement therapy).
  • Vitamin D intake is similarly important, which helps calcium absorption and maintenance of muscle strength (400IU per day until age 60, 600-800 IU per day after age 60).
  • Get regular exercise, especially weight bearing exercise.

A number of medications are also used for the prevention and treatment of osteoporosis:

  • Bisphosphonates: Comes in several formulations: Alendronate (Fosamax) and risedronate (Actonel) are oral medications, whereas Zoledronic Acid (Reclast) Ibandronate (Boniva) are intravenous. These medications help slow down bone loss and decrease the risk of fractures.
  • Calcitonin (Calcimar, Miacalcin): A hormone made from the thyroid gland and is usually given as a nasal spray or as an injection under the skin. It may help prevent spine fractures, and is helpful to control pain after an osteoporotic vertebral (spine) fracture.
  • Estrogen or Hormone Replacement Therapy: Estrogen therapy alone or in combination with another hormone, progestin, has been shown to decrease the risk of osteoporosis and osteoporotic fractures in women. The combination of estrogen with a progestin however has been shown to increase the risk for breast cancer, strokes, heart attacks and blood clots. Estrogens alone may increase the risk of strokes. Given the complexity of this decision, consult with your doctor about whether hormone replacement therapy is appropriate for you.
  • Selective Estrogen Receptor Modulators (SERMs): Medications that mimic estrogens good effects on bones without some of the serious side effects such as breast cancer. Raloxifene ( Evista ) decreases spine fractures in women, and is approved for use only in women.
  • Teriparatide (Forteo): A form of parathyroid hormone that stimulates bone formation. It is approved for use in postmenopausal women and men at high risk for osteoporotic fracture. It is given as a daily injection under the skin and can be used for up to 2 years. Patients with prior radiation treatment to the bones or with elevated parathyroid hormone levels should avoid this medication.

Prevention

Lifestyle modification may be the best way of preventing osteoporosis:

  • Calcium intake in your diet;roughly 1000-1500 mg/day, depending on your age (see above)
  • Vitamin D intake (between 400-800 IU/day)
  • Avoid tobacco smoking
  • Avoid excess alcohol intake
  • Engage in weight-bearing exercises
  • Treat underlying medical conditions that can cause osteoporosis
  • Minimize or change medications that can cause osteoporosis; never stop taking any medication without speaking with your doctor first
  • If you are at high risk for falls, consider using hip protectors (e.g. SAFEHIP ®)

Broader health impact of osteoporosis

The most health-threatening consequence of osteoporosis is a fracture. Specifically, spine and hip fractures may lead to chronic pain, long-term disability and even death. The major goal of treating osteoporosis is to prevent fractures.

Living with osteoporosis

Once given the diagnosis of osteoporosis, it is important to prevent further bone loss and risk for bone fracture. Eliminate hazards in the home that can increase your risk of falling (remove loose wires or throw rugs, install grab bars in the bathroom and non-skid mats near sinks and in the tub, etc.). Use proper technique and support when carrying or lifting heavy objects. Wear sturdy shoes, especially in winter. Use a cane or walker if you have balance problems or other difficulties walking.