Women and Postmenopausal Osteoporosis
Osteoporosis (thinning of the bones) occurs in both genders, but is more common in women. Women often enter into menopause with a lower bone mass than men. They then experience even greater bone loss during menopause. This lower bone mass may be caused by decreasing estrogen levels as well as lower calcium and vitamin D intake.
Once a woman begins to experience bone loss she is at risk for developing osteoporosis. Other risk factors include advancing age, low body weight, maternal history of osteoporosis, history of previous fracture(s), and poor calcium or vitamin D consumption.
The symptoms of postmenopausal osteoporosis range from no noticeable signs to disabling fractures. The bones of women with osteoporosis are very thin and break easily. It is not uncommon for a fracture to occur with only minimal force. The pain and physical limitations that occur from fractures can significantly affect a person's quality of life. For example, following a hip fracture, a woman may have difficulty walking and taking caring of her daily needs like cooking, bathing, and getting out of the house. She may require intensive in-home nursing/personal care, or in some cases, require short or long-term admission to a nursing home.
The diagnosis of osteoporosis is made on the basis of two criteria: 1) a woman is at risk for bone loss and 2) her bones fracture easily. Additional diagnostic information obtained by a DEXA scan (dual emission x-ray absorptiometry) identifies the severity of osteoporosis and helps monitor treatment. The DEXA scan measures the thickness (bone density) of the bones. Based on the DEXA results, a woman is diagnosed with normal bone density, osteopenia (mild bone loss) or osteoporosis. Once a diagnosis is made, further evaluation may be necessary to pinpoint the specific reason for bone loss, such as over-production of the parathyroid hormone (a hormone that takes calcium out of the bones and transmits it to the blood), vitamin D deficiency (from poor diet or lack of sunlight), or diseases of the bone such as multiple myeloma (a type of bone marrow cancer that destroys bone and results in fractures).
Current recommendations suggest that women should be screened once when they turn 65 if they have no known risks for osteoporosis. However, if a woman is at risk she should be screened earlier. The frequency of further DEXA scans is determined by a physician based on the results of the scan and a woman's medical history.
The goals of treatment are to prevent a first fracture in patients with low bone density, and to prevent additional fractures in patients who have already had one or more breaks. Even with treatment, women may still experience a fracture. Treatment can only decrease the risk of future fractures up to 50 percent.
Lifestyle changes are lifetime commitments in the treatment of osteoporosis. Bone formation relies on both calcium and vitamin D. Therefore, women should make sure that they have adequate amounts of both vitamins in their diets and/or use supplements. Calcium supplementation helps mineralize the newly formed bone. A woman should be getting 1500 mg of calcium per day either through diet or supplements.
Vitamin D helps maintain the bone and improves the absorption of calcium. It also improves muscle strength and decreases the risk of falling. Up to two-thirds of patients with a hip fracture have a vitamin D deficiency. Vitamin D can be obtained either through diet or sun exposure. Given that many older adults do not get outside often (especially if they live in nursing homes and assisted living buildings), and frequently use sunscreen, taking supplements may be particularly important for this age group. A woman should get 800 IU per day of vitamin D.
Other lifestyle changes focus on decreasing a person's risk of falling (and therefore, their risk of fracture). Such changes include: reducing the use of alcohol (which can affect balance and judgment), avoiding long periods of bed rest and inactivity (which leads to rapid bone loss and muscle weakness), and increasing aerobic, weight bearing and resistance exercises (which increase bone mineral density and strengthen muscles). Other measures in the home that may decrease the risk of falls include taping down rugs, moving furniture out of high traffic areas, and using night-lights.
Medications to treat osteoporosis are designed to either stop bone breakdown or to increase new bone formation. In the recent past, hormone replacement therapy was an important treatment. However, given the concern for an increased risk of cardiac disease and stroke with prolonged HRT (please see our previous discussion on controversies in menopause), HRT is no longer routinely recommended as a treatment for osteoporosis.
Now, the most commonly used medications to treat osteoporosis are usually the bisphosphonates, such as alendronate and risedronate. Trials of these medications show that women who use these medicines experience an increase in bone mineral density. They also decrease the chance of hip and other fractures by about 50 percent. The most serious side effect from these types of medicines is esophagitis, or inflammation and burning of the esophagus. Taking the medicine with food thirty minutes before a meal and avoiding lying down for thirty minutes after the medicine is taken can decrease this side effect. In addition, women can take bisphosphonates one time per week to further decrease the risk of esophagitis. If the bisphosphanates cannot be used, other medications (such as calcitonin and selective estrogen receptor modulators like raloxifen) can also be used.
A woman can decrease her risk of developing osteoporosis by quitting smoking, maintaining a healthy weight and adequate calcium intake, and by exercising regularly. If a woman has osteoporosis, aggressive treatment is necessary (as described above) to decrease the likelihood of fractures. As mentioned previously, hip fractures are particularly problematic. Hip fractures often lead to being placed in a care home or even death shortly after.