Osteoporosis

Osteoporosis

Osteoporosis is a disease process that leads to lowered, bone mass and subsequent decrease in strength, which makes the individual at increased risk for fracture. It is estimated that about 20% of postmenopausal, white women in the United States have osteoporosis. One out of every two women will sustain an osteoporosis, related fracture at some point in her lifetime. The most common fractures are the spine, hip, and wrist. Elderly patients who sustain a hip fracture, will increase their risk of mortality by 10 to 20% within one year. Only 40% of patients will regain their pre-fracture level of independence.

The bone mass in an adult, achieves its peak between the ages of 25 and 30. Numerous factors including genetic, nutritional, endocrine, physical activity and general health contribute to peak bone mass. The amount of bone in the body is a balance between formation and removal. When the process of removal outpaces formation, a gradual loss of bone mass will result. Some factors will contribute to the acceleration of bone loss. The time of menopause is a commonly recognized period of life when bone loss accelerates.

There are numerous risks factors that when combined with the time of menopause, can notably increase risk for osteoporosis and subsequent related fractures.

Major Risks Factors in Caucasian Postmenopausal Woman:

  • Previous history of fracture, as an adult.
  • Low body weight, less than 125 pounds.
  • Current smoking.
  • Use of oral corticosteroid therapy for more than three months.

Additional Risks Factors:

  • Estrogen deficiency at an early age, (less than 45 years).
  • Generally poor health/frailty.
  • Low calcium intake.
  • Low physical activity.
  • Increaesed alcohol intake, greater than two drinks per day.

The diagnosis of osteoporosis can be determined by the bone mineral density, (BMD) test. There are other conditions i.e., hyperparathyroidism, or osteomalacia that can also be associated with low BMD. Numerous other diseases can be associated with an increased risk for osteoporosis, these include:

  • AIDS.
  • Pulmonary disease
  • Anorexia.
  • Bowel diseases impairing normal absorption of nutrients.
  • Diabetes.
  • Rheumatoid arthritis.
  • Liver disease.
  • Malnutrition.

There are also some medications that can be associated with a decrease in bone mineral density. Some of these are:

  • Anti-seizure medications.
  • Steroids.
  • Immunosuppressants.
  • Lithium.
  • Excessive thyroid medication.

BMD (Bone Mineral Density) measurement is most accurate using a central DXA scan of the hip. This is the best predictor for future hip and associated fractures. This value will then be compared with others similar in age and sex to the patient (Z-score), or to "young, normal" adults of the same sex, (T-score). One standard deviation equals about 10 to 20% of the bone density. Low bone mass, (Osteopenia), is a BMD at -1 to -2.5. Osteoporosis is defined as a BMD of -2.5 or greater on the adult T score.

BMD testing should be performed on:

  • All women greater than 65.
  • Younger women if other risks factors are present.
  • Postmenopausal women presenting with fractures.

Medicare covers BMD testing in patients older than 65 if the patient:

  • Is estrogen deficient and at clinical risk for osteoporosis.
  • Has vertebral abnormalities.
  • Is receiving steroid therapy.
  • Has hyperparathyroidism.
  • Needs the test for ongoing monitoring of osteoporosis treatment.

Medicare allows repeat BMD testing every two years.

Clinical trials had demonstrated that supplemental Calcium 1200 mg - 2500 mg and Vitamin D, 400 IU to 800 IU per day, when taken in combination can decrease the risk for osteoporosis related fractures. Regular weight bearing exercises, muscle strengthening, and agility and balance exercises can maintain bone quality as well as decrease the risk for falling. Tobacco products and excessive alcohol also have a negative affect on bone quality and increases fracture risk in menopausal women. Their use should be curtailed. Treatment for osteoporosis should be initiated in cases where:

  • BMD T - scores are below 2.0 by hip DXA, with no risk factors.
  • BMD T - scores are below 1.5 by hip DXA, with one or more risk factors.
  • A history of prior vertebral or hip fracture is present.

Since bone loss will accelerate at the time of menopause, treatment should be initiated without delay. FDA approved drugs for prevention and/or treatment of postmenopausal, osteoporosis include:

  • Bisphosphonates, (Fosamax) Actonel, Calcitonin, Estrogen/Hormone Therapy, Thyroid Hormone, Raloxifene.

Osteoporosis treatment will require monitoring by subsequent BMD testing after one to two years. BMD testing has a margin of error between 2 and 4% in the vertebrae, 3 and 6% in the hip. It is commonly thought that even though the BMD test may not increase, there is still some benefit in preventing fracture risk, when on treatment.

Material summarized from the National Osteoporosis Foundation