osteoporotic

Loss of bone mass throughout the skeleton, predisposing patients to fractures. Healthy bone constantly remodels itself by taking up structural elements from one area and patching others. In osteoporosis, more bone is resorbed than laid down, and the skeleton loses some of the strength that it derives from its intact trabeculation. Aging causes bone loss in both men and women, predisposing them to vertebral and hip fractures. This is called type II osteoporosis (formerly “senile” osteoporosis). Type I osteoporosis (also known as “involutional” bone loss) occurs as a result of the loss of the protective effects of estrogen on bone that takes place at menopause. Synonym: bone loss; rarefaction of boneosteoporotic (-rot'ik), adjectiveillustration;

Etiology

Several modifiable factors contribute to bone mass and strength: increased body weight, higher levels of sex hormones, and frequent weight-bearing exercise all build up bone and prevent fractures. Bone loss and the risk of fractures increase with age, immobilization, excess of thyroid hormone, use of corticosteroids and some anticonvulsant drugs, the consumption of alcohol, tobacco, and caffeine, and after menopause. Genetics (a nonmodifiable risk factor) also contributes to osteoporosis. See: table

Symptoms

Bone loss progresses for many years without causing symptoms. When it results in fractures, bone pain and loss of mobility may be disabling. Signs of osteoporosis include deformities of the skeleton, e.g., kyphosis (“dowager’s hump”), and loss of height, esp. if vertebral compression fractures occur.

Treatment

Supplemental calcium and regular exercise help slow or prevent the rate of bone loss and are recommended for most men and women. Bisphosphonate drugs, e.g., alendronate, calcitonin, sodium fluoride, and other agents are useful for patients of both sexes. In menopausal women, estrogen supplementation or the selective estrogen receptor modulators help prevent bone loss and fractures, but calcium supplementation has not been shown to be helpful.

Patient care

Protection against osteoporosis should begin in childhood and adolescence and focus on building bone mass. Children should be encouraged to eat foods rich in calcium; parents should be taught to encourage regular exercise, including school gym classes and sports programs, to build strong bones and establish healthy habits. Parents should also be informed about the effects that eating disorders, excessive dieting, excessive exercise, alcohol consumption, and smoking have on bone density. From the mid-20s through age 35, focus continues to be placed on building and maintaining bone mass through a calcium-rich diet. After age 35, bone resorption exceeds bone formation. Emphasis is placed on preventing bone loss through a healthy diet, use of calcium (plus vitamin D) supplements (an intake of at least 1000 mg of calcium per day), and weight-bearing exercises, e.g., weight-lifting, walking, jogging, dancing, and climbing stairs. High-impact aerobics may create too much stress on the bones of older adults and should be avoided.

After patients have been diagnosed with osteoporosis, time should be spent assessing their diets and activity levels. Although patients should engage in walking or other weight-bearing activity for 30 to 60 min three to four times a week, this goal may need to be approached slowly. Foods rich in calcium include dairy products, spinach, sardines, and nuts. Calcium supplements totaling 1000 to 1500 mg per day should be consumed and can prevent further bone loss. Based on bone density testing, alendronate or another drug that inhibits bone resorption may be prescribed in a daily or weekly formulation. Bisphosphonates like alendronate should be taken on an empty stomach with a full glass (8 oz) of water. The patient should remain in an upright position for 30 min after taking these medications to avoid pill-induced esophagitis.

Diagnosis

The National Osteoporosis Foundation (NOF) and the World Health Organization (WHO) recommend tests to determine bone mineral density, e.g., dual energy x-ray absroptiometry (DEXA scanning) in patients with specific diseases or conditions. The NOF recommends that all women over 65 and all men over 70 undergo testing. The NOF also recommends bone density testing for anyone over 50 who fractures a bone and for women of menopausal age who have risk factors (see Table "Risk Factors for Osteoporosis").

Localized osteoporosis of the skull associated with Paget's disease.

Osteoporosis due to the lack of normal functional stress on the bones. It may occur during a prolonged period of bedrest or as the result of being exposed to periods of weightlessness, e.g., astronauts in outer space.

Bone loss that results from prolonged treatment with oral or inhaled steroids, e.g., prednisone, beclomethasone, or triamcinolone.

A rare childhood disease of inadequate bone mineral density, characterized by poor bone formation that usually improves spontaneously during puberty or young adulthood. Affected children often complain of bone or back pain, muscle weakness, or impaired gait. Fractures of long bones and vertebral compression fractures are common. Other diseases of bone formation, such as osteogenesis imperfecta, must be excluded before a diagnosis of juvenile osteoporosis is made. Affected children are usually asked to refrain from participation in sports to lessen the risk of fractures. Synonym: idiopathic juvenile osteoporosis

Loss of bone tissue following trauma, esp. when there is damage to a nerve supplying the injured area. The condition may also be caused by disuse secondary to pain.