Osteoporosis is characterized by low bone mass, microarchitectural disruption, and increased skeletal fragility.
Risk Factors for Osteoporotic Fractures
Personal history of fracture as an adult.
History of fracture in a firstdegree relative.
Current cigarette smoking.
Lifelong low calcium intake.
Low body weight (less than 58 kg [127 lb]).
Inadequate physical activity.
Estrogen deficiency (menopause before age 45 years or bilateral ovariectomy, prolonged premenopausal amenorrhea [greater than one year]).
Impaired eyesight despite. adequate correction.
Screening for osteoporosis and osteopenia
Normal bone density
is defined as a bone mineral density (BMD) value within one standard deviation of the mean value in young adults of the same sex and race.
is defined as a BMD between 1 and 2.5 standard deviations below the mean.
is defined as a value more than 2.5 standard deviations below the mean; this level is the fracture threshold. These values are referred to as T-scores (number of standard deviations above or below the mean value).
Dual x-ray absorptiometry. :
In dual x-ray absorptiometry (DXA), two photons are emitted from an x-ray tube. DXA is the most commonly used method for measuring bone density because it gives very precise measurements with minimal radiation. DXA measurements of the spine and hip are recommended.
Biochemical markers of bone turnover. Urinary deoxypyridinoline (DPD) and urinary alpha-1 to alpha-2 N-telopeptide of collagen (NTX)
are the most specific and clinically useful markers of bone resorption. Biochemical markers are not useful for the screening or diagnosis of osteoporosis because the values in normal and osteoporosis overlap substantially.
Recommendations for screening for osteoporosis
All women should be counseled about the risk factors for osteoporosis, especially smoking cessation and limiting alcohol. All women should be encouraged to participate in regular weight-bearing and exercise.
Measurement of BMD is recommended for all women 65 years and older regardless of risk factors. BMD should also be measured in all women under the age of 65 years who have one or more risk factors for osteoporosis (in addition to menopause). The hip is the recommended site of measurement.
All adults should be advised to consume at least 1,200 mg of calcium per day and 400 to 800 IU of vitamin D per day. A daily multivitamin (which provides 400 IU) is recommended. In patients with documented vitamin D deficiency, osteoporosis, or
previous fracture, two multivitamins may be reasonable, particularly if dietary intake is inadequate and access to sunlight is poor.
Treatment is recommended for women without risk factors who have a BMD that is 2 SD below the mean for young women, and in women with risk factors who have a BMD that is 1.5 SD below the mean.
Nonpharmacologic therapy of osteoporosis in women
An optimal diet for treatment (or prevention) of osteoporosis includes an adequate intake of calories (to avoid malnutrition), calcium, and vitamin D.
Postmenopausal women should be advised to take 1000 to 1500 mg/day of elemental calcium, in divided doses, with meals.
total of 800 IU daily should be taken.
Women should exercise for at least 30 minutes three times per week. Any weight-bearing exercise regimen, including walking, is acceptable.
Cessation of smoking
is recommended for all women because smoking cigarettes accelerates bone loss.
Drug therapy of osteoporosis in women
Selected postmenopausal women with osteoporosis or at high risk for the disease should be considered for drug therapy. Particular attention should be paid to treating women with a recent fragility fracture, including hip fracture, because they are at high risk
for a second fracture.
Alendronate (Fosamax) (10 mg/day or 70 mg once weekly) or risedronate (Actonel) (5
mg/day or 35 mg once weekly) are good choices for the treatment of osteoporosis.
Bisphosphonate therapy increases bone mass and reduces the incidence of vertebral and
Alendronate (5 mg/day or 35 mg once weekly) and risedronate (5 mg/day of 35 mg once
weekly) have been approved for prevention of osteoporosis.
Alendronate or risedronate should be taken with a full glass of water 30 minutes before the first meal or beverage of the day. Patients should not lie down for at least 30 minutes after taking the dose to avoid the unusual complication of pillinduced esophagitis.
Alendronate is well tolerated and effective for at least seven years.
The bisphosphonates (alendronate or risedronate) and raloxifene are first-line treatments
for prevention of osteoporosis. The bisphosphonates are first-line therapy for treatment
of osteoporosis. Bisphosphonates are preferred for prevention and treatment of osteoporosis because they increase bone mineral density more than raloxifene.
Selective estrogen receptor modulators
Raloxifene (Evista) (5 mg daily or a once-aweek preparation) is a selective estrogen receptor modulator (SERM) for prevention and treatment of osteoporosis. It increases bone mineral density and reduces serum total and low-densitylipoprotein (LDL) cholesterol. It also appears to reduce the incidence of vertebral fractures and is one of the first-line drugs for prevention of osteoporosis.
Raloxifene is somewhat less effective than the bisphosphonates for the prevention and treatment of osteoporosis. Venous thromboembolism is a risk.
Treatment Guidelines for Osteoporosis
Calcium supplements with or without vitamin D supplements or calcium-rich diet
Avoidance of alcohol tobacco products
Monitoring the response to therapy
Bone mineral density and a marker of bone turnover should be measured at baseline, followed by a repeat measurement of the marker in three months. If the marker falls appropriately, the drug is having the desired effect, and therapy should be continued for two years, at which time bone mineral density can be measured again. The anticipated three-month decline in markers is 50 percent with alendronate.
Estrogen-progestin therapy is no longer a firstline approach for the treatment of osteoporosis in postmenopausal women because of increases in the risk of breast cancer, stroke, venous thromboembolism, and coronary disease.
Indications for estrogen-progestin in postmenopausal women include persistent
menopausal symptoms and patients with an indication for antiresorptive therapy who cannot tolerate the other drugs.