Osteoporosis is a bone disease characterized by low bone density and abnormal bone architecture. It is most common in women after menopause because estrogen enhances bone integrity. Osteoporosis can also result from steroid use or treatment, excessive alcohol use, certain antiseizure medications, and overactivity of the thyroid gland. The main adverse effect of osteoporosis is fracture of bone, the most common sites of fracture being the spine and hip.
Osteoporosis is so common that I go to great strides to prevent and treat it. Every woman over age 65 should have a bone density test (DXA); I also recommend testing for anyone with the risk factors mentioned above, or a postmenopausal woman under age 65 who is underweight or has a personal history of a fragility fracture. A fragility fracture is one that occurs from a standing height or lower in the absence of significant trauma such as a motor vehicle accident. Many times my patients will tell me that they tripped and broke a bone, not realizing that this raises concerns that their bone density may be low.
Bone density is tested with the DXA scan; in this test the subject's bone density is compared to the normal bone density of 30-year-olds of the same gender. Several sites are measured in the spine and hip, and a T-score is assigned. This is a statistical term measuring the standard deviation from the 30-year-old norm. We use the T-score to make decisions about treatment and to measure improvement over time.
Every adult should strive to get enough calcium and vitamin D for bone health. Adolescents require 1300 mg of calcium daily at this crucial time of bone growth. Premenopausal women should get 1000 mg, and postmenopausal women 1200-1500 mg. Vitamin D requirements are 400-800 international units daily, the larger amount being recommended for postmenopausal women. To determine the number of mg in a serving of dairy products, look on the label and add a "0" to the percent of the recommended daily allowance (RDA) that is noted. A glass of milk, with 30% of the RDA, has 300 mg of calcium. This method provides a more accurate assessment for different age groups. Also important in the fight to keep bones healthy is regular weight-bearing exercise.
Most of the prescription medications we use focus on reducing bone resorption; common examples include alendronate (Fosamax), Actonel, Boniva, and Evista. For severe cases or when patients don't respond to these, there is a bone building treatment called Forteo that can be used for 2 years.
For those of you with children and adolescents, encourage calcium-rich foods and exercise, as these are crucial factors to enable them to reach a high peak bone density. After age 30 our bone density starts to decline, and if we have reached a sufficient peak, we can stand the loss without making us at risk of fracture.