Postmenopausal Osteoporosis-- prevention

Alternatives to estrogen replacement therapy

Estrogen improves calcium absorption and reduces the amount of calcium lost in urine. Hormone replacement is not for everyone however, due to concerns of side effects as well as increased risk of breast and possibly uterine cancer

Recent research has shown that regular sessions of weight-bearing exercise, coupled with 1500 mg of calcium and 400-800 IU of vitamin D daily, can stop bone loss for some postmenopausal women. Results have been especially encouraging for those who participate in exercise programs designed to head off osteoporosis.

Direct measurement of bone density is the only way to be sure about the status of a woman's skeleton. Many physicians feel that all menopausal women who are wavering about estrogen replacement therapy (ERT) should have a density test. A woman's skeleton reaches its peak mass in her mid-thirties, and by the time she reaches menopause her bone mass will have changed as a result of aging and other factors, such as smoking and drinking (which reduce bone mass) and calcium intake and exercise (which build it). Density studies are performed at hospitals and freestanding imaging centers. One of the best scanning techniques, dual energy X-ray absorptiometry, offers both accuracy and minimal radiation exposure.

If the study indicates that a woman already has osteoporosis, then an exercise-calcium-vitamin program by itself will probably not offer sufficient protection. Her doctor may instead recommend treatment with Estrogen replacement therapy .

The bone density test can serve as a benchmark for preventive efforts. Many experts recommend having a second measurement 12 to 24 months later to make sure the protective program is working. After that, additional tests aren't needed unless her life-style or other health circumstances change dramatically.

Beneficial exercise needs to be frequent, progressive in intensity, and a habit. The best exercises "are those that ask the muscles to work harder than they would normally. The muscles, in turn, work on the bones. When a set of exercises becomes easy, it's time to work longer or harder.

The best exercises for strengthening bones include brisk walking, strength training, stair climbing, hiking, and dancing. Although swimming and cycling are good aerobic exercises, they put less weight on the bones -- and therefore do less to increase skeletal mass.

Any amount of physical activity is better than none at all. Some experts feel that ordinary activities such as gardening, raking, and house- work also help maintain physical fitness and healthy bones. However, anyone who has problems with balance or gait, or who hasn't moved a muscle in years, should consult a physician or a physical therapist before taking up vigorous exercise.

Since a woman's body uses calcium less efficiently after estrogen production falters, a woman needs to step up her calcium intake to 1500 mg daily when she suspects she is beginning menopause.

Many women do not get enough calcium from foods, particularly if they dislike milk, are lactose intolerant, or shun dairy products as being too high in fat. Researchers estimate that most people get only 400-600 mg of dietary calcium daily. Most physicians recommend taking supplements to compensate for calcium shortfalls.

Exercise causes the bones to use more calcium, and a healthy diet provides active bones with the raw materials they need. But there's an import- ant link in the metabolic chain: without vitamin D the small intestine can't absorb adequate calcium, no matter how much is available.

During most oft he year, vitamin D is synthesized by skin that is exposed to sunlight for at least 20 to 30 minutes daily. In winter, however, this doesn't happen for many people living in the continental United States. Not only are the ultraviolet rays that trigger the vitamin's production unavailable in winter, but also the duration of winter increases with distance from the equator. So in the northern tier of the United States -- above latitude 42 degrees north -- the skin can't make any vitamin D from November through February, or longer. During these months especially, nutritionists suggest taking 400 IU in a daily multi-vitamin tablet.

Researchers have also found that people over 65 have a difficult time manufacturing enough vitamin D at any time of year. According to scientists at the New England Medical Center, aging reduces the capacity of the skin to use sunlight to produce vitamin D. Some researchers now believe that vitamin D intake should be increased to 800 IU per day starting at age 65 to 70, and some scientists say that anyone over 50 should take 800 IU year-round. Larger amounts aren't recommended because they may be toxic.

Estrogen-replacement therapy coupled with an exercise and diet at present seems to be the best answer for older women who need to be concerned about minimizing bone loss. But it's not the only answer. A hormone- free program can be effective for women who understand their calcium requirements and who are resolute about regular exercise, a calcium-rich diet, and daily vitamin and mineral supplements.

Pre-menopause (mid-20s to early 50s)

1000 mg calcium/day 200 IU VITAMIN D/day

Menopause (early 50s to late 60s)

1000 mg calcium/day 400-800 IU VITAMIN D/day if taking ERT

1500 mg calcium/day 400-800 IU VITAMIN D/day if not taking ERT

Post menopause(late 60s, early 70s, and beyond)

1000 mg calcium/day 800 IU VITAMIN D/day if taking ERT

1500 mg calcium/day 800 IU VITAMIN D/day f not taking ERT

(Most ordinary multi vitamin tablets contain 400 IU VITAMIN D)

Exercise

Women who exercise regularly, regardless of age, should increase progressively up to 30- 60 minutes 3-5 days per week, include low-to-moderate weight-bearing exercises for variety, such as brisk walking, stair-climbing, dancing, hiking, or aerobics. Sedentary women should start walking (indoors or out) in proper footwear for 10 minutes per day 3 times a week; increase by one minute each week. Be patient and don't give up even if progress is slow. Walk with a friend or with a group for company, but don't compete with your companions.



Estrogen Replacement Therapy and Heart Disease

Many women who decide to take hormone-replacement therapy (HRT) base their decision on its reported protection against heart disease, the leading cause of death among women. Now a team of Dutch epidemiologists says that these benefits may have been exaggerated.

Results from large observational investigations have indicated that women who take HRT are 35-45% less likely to die from heart disease than those who don't, prompting many physicians to advocate HRT.

But some epidemiologists suspected that part of this apparent benefit was due not to any medical intervention but to generally better health among women who are likely to use HRT. Therefore, they hypothesized that healthy women who can afford regular medical care are more likely to have lower rates of all illnesses, not just heart disease. These are also the women most likely to use estrogen supplements.

Researchers from Leiden University Hospital in the Netherlands analyzed 18 large HRT studies, comparing the participants' risk of heart disease with their risk of cancer. The same studies that indicated HRT protected against heart disease also showed low rates of cancer. In fact, the investigations that demonstrated the greatest reduction in heart disease among HRT users also showed the largest decrease in cancer cases.

But HRT does not protect against cancer and, in fact, some studies show that women who take HRT have a slightly higher risk of developing breast cancer. The Dutch researchers' findings suggest that the women taking HRT were healthier than non-users and probably had a lower risk of heart disease in the first place. (British Medical Journal, May 14, 1994, pp. 1268-1269).