Osteoporosis

by Sheila A. Dugan, M.D., P.T.

Osteoporosis, a disease characterized by reduction of bone mass, is called the ‘silent epidemic’. Currently, an estimated 8 million American women and 2 million American men suffer from osteoporosis and another 33 million Americans have low bone mass. Bone mass loss leads to bone fragility and fracture and causes pain, disfigurement and disability. The numbers of affected individuals will increase to epidemic proportions as the percentage of older persons increases beyond the year 2002. Many persons are unaware they are afflicted until they present with a fracture and advanced bone disease.

Risk factors for osteoporosis have been identified. One out of every two Caucasian woman in the U.S. will suffer an osteoporotic fracture in her lifetime. Around the time of menopause, the reduction in estrogen levels causes excessive loss of bone mineralization. Certain diseases and medications have been associated with osteoporosis such as hyperthyroidism or high dose corticosteroid intake. Cigarette smoking, excessive alcohol intake and poor dietary habits can also cause this type of bone loss.

Unfortunately, once the bones have thinned, it is difficult to regain bone density. That is why prevention is the best strategies for dealing with osteoporosis. Studies have shown that the three most critical factors for prevention include estrogen replacement, calcium supplementation, and regular exercise. Patients at risk should have a bone density measurement, called DEXA or dual-energy x-ray absorptiometry. It measures the density of the thigh-bone (femur) and low back (lumbar) vertebrae.

Once the diagnosis of osteoporosis is confirmed with a bone mineral density measurement, treatment must be initiated. The principles of treatment are to rebalance the bone remodeling cycle. A comprehensive approach to osteoporosis includes: medications, modification of risk factors, and rehabilitation, including pain control, fracture management, posture and exercise.

Medications used for osteoporosis are from several different groups and play a role in the bone remodeling pathways. Hormonal agents including estrogen and progesterone are taken to maintain the physiological dose the body made prior to menopause. This prevents against further bone loss. Because prolonged estrogen replacement therapy may slightly increase a women’s risk for breast cancer, the decision to prescribe hormone replacement therapy is based on one’s personal and family health history. Bisphosphonates are agents that can also affect the remodeling of the skeletal system and improve one’s bone density. Like estrogen, they have been shown in studies to reduce the risk of fractures of the spine. Because of the side effect of gastrointestinal ulceration, they must be taken on an empty stomach, first thing in the morning, and while sitting upright. Because they do not affect the breast or heart tissue, there is no associated increased risk of breast cancer or decreased risk of heart disease associated with their use. If the first two classes of medications cannot be used because of the risks and side effects noted, Calcitonin is another agent that can impact the bone. However, it has not been shown to reduce the risk of fracture. It is administered via nasal inhalation and is a potent pain reliever.

Calcium and Vitamin D play a crucial role in bone remodeling. If one’s diet does not provide adequate calcium, it may be borrowed from the bone reserve instead. Post-menopausal women require a total of 1,500 mg of Calcium daily while men and pre menopausal women require 1,000 mg daily. The recommended daily dose of Vitamin D is 800 IU. Vitamin D taken in conjunction with Calcium can improve absorption. There are many excellent dietary sources such as green leafy vegetables and dairy products, which contain Calcium and are supplemented with Vitamin D.

A regular weight bearing exercise program is another key component of osteoporosis prevention and management. In studies, optimal results in maintaining bone density are found when a combination of hormone replacement, calcium and exercise are used together. Weight bearing activities like walking or running stimulate bone density. This is especially crucial in one’s 20’s when one’s peak bone mass is laid down, but remains important at any age in maintaining the present level. If exercise is discontinued, the positive effect on bone density is lost.