Osteoporosis and Menopause

Preventing and Reversing Osteoporosis : What You Can Do About Bone Loss--A Leading Expert's Natural Approach to Increasing Bone Mass by Alan R. Gaby
The Osteoporosis Book by Nancy E. Lane (editor)
Osteoporosis in Clinical Practice : A Practical Guide for Diagnosis and Treatment by Diet Geusens
150 Most-Asked Questions About Osteoporosis : What Women Really Want to Know by Ruth S. Jacobowitz
	Visit the Home Page of William E. Straw, M.D.

Osteoporosis is a condition in which bones lose their normal strength, becoming "porous" and weak. Osteoporosis can affect both men and women, but it tends to occur in women more frequently and at an earlier age. Osteoporosis is caused by an imbalance in a normal process called "bone remodeling." During this process, there is a continuous cycle of breakdown and repair which takes place in all bones throughout life. Special cells called osteoclasts eat away or "resorb" areas of old, damaged bone. Other cells called osteoblasts then fill in the empty spaces withnew bone.

Osteoporosis can be caused either by too much "resorption" of old bone, or too little formation of new bone. The result is a bone which is weaker than normal and may break with a minor injury, or even break spontaneously. The most common bone fractures which occur in women with osteoporosis are fractures of the hip, vertebrae (spinal bones), and wrist. Hip fractures are the most serious because they need to be repaired surgically. Fractures of the vertebrae are called "compression fractures" because the vertebral bone does not break in two; instead, the bone becomes so weak that it simply collapses on itself. The curvature of the spine seen in many women with osteoporosis is a result of a series of these compression fractures of the vertebral bones.

A variety of factors can affect your chances of developing osteoporosis. The most common of these so-called "risk factors" are listed below:

Female Gender	Increasing age
Menopause	Asian or Caucasian heritage
Small body build	Smoking
Inadequate calcium intake	Excessive alcohol use
Lack of exercise	Hyperthyroidism
Long-term use of corticosteroids	Use of some anticonvulsants

Two of the most important risk factors are simply female sex and increasing age. Women are affected by osteoporosis much more than men, partly because they simply live longer than men. Also, women tend to reach a lower "peak bone mass" than men. Both men and women reach their highest bone mass (or greatest bone strength) at about age 30. After this age, bone strength gradually declines. One way to prevent some of the damage caused by osteoporosis is by ensuring that children and young adults get sufficient exercise and dietary calcium to reach as high a "peak" bone strength as possible.

Lack of estrogen definitely contributes to osteoporosis. This occurs most dramatically at menopause - many women experience a period of rapid bone loss, losing 3-5% of their bone strength per year in the first several years after menopause(8). However, estrogen deficiency at other times can also lead to osteoporosis. For instance, women who are very athletic or who have eating disorders may go for long periods without menstruating. This can mean that less estrogen is present than normal. For such women, taking estrogen in the form of birth control pills may be recommended to help prevent osteoporosis.

The best approach to osteoporosis is prevention. Once bone loss has occurred, even the best treatments available are not enough to restore completely normal bone strength; some medications can improve bone strength by 10% and possibly more(11), but this still does not make the bones as strong as they would have been if good preventive steps had been taken from the beginning.

The key features of osteoporosis prevention are getting enough calcium and vitamin D, keeping up a program of regular exercise, and - for many women - using hormone replacement therapy after menopause. It is also very important to stop smoking if you are a smoker, since moking increases the risk of osteoporosis significantly.

Calcium in the diet is used in maintaining normal bone strength. The "average" American diet contains about 300-500 mg of calcium daily. Young women between the ages of 11-24 need a much higher calcium intake of 1200-1500 mg of calcium daily. Women aged 25-50 who have not gone through menopause should have a calcium intake of 1000 mg daily. After menopause, a calcium intake of 1000 mg per day is still recommended for women who are receiving estrogen replacement therapy, while a higher intake of 1500 mg per day is advised for women who are not taking estrogen(7).

Milk and milk products have the highest natural calcium content, but some foods such as cereals and orange juice are "fortified" with calcium - extra calcium has been added to them so that they provide more calcium than they otherwise would. Low-fat and skim milk contain just as much calcium as regular "whole" milk.

Food	Calcium
8 oz. yogurt	300 mg.
8 oz. cup of calcium fortified orange juice	300 mg.
1.5 oz of cheese	300 mg.
8 ounce cup of milk	300 mg.

Non-dairy sources of calcium include beans, broccoli, bok choy, and canned fish with bones (such as sardines or mackerel).

Two widely available calcium supplements are "calcium carbonate" (Os-Cal, TUMS, and others) and "calcium citrate" (Citracal and others). Calcium citrate is thought to be somewhat more readily absorbed into the circulation; for this reason, four tablets of Citracal - which supply a total of 800 mg of calcium - is considered equivalent to 1000 mg of calcium carbonate.

Some researchers have found that calcium is more readily absorbed when chewed rather than swallowed whole. TUMS tablets are meant to be chewed, and they are actually cheaper than most calcium tablets. A regular-strength TUMS contains 200 mg of calcium, while an extra-strength TUMS contains 300 mg. TUMS-500 tablets containing 500 mg of calcium are also available.

In choosing calcium tablets, be sure to look for the "elemental calcium" content, not just the number of milligrams of the active ingredient - for instance, although a regular strength TUMS tablet contains 500 mg of "calcium carbonate," the amount of "elemental calcium" is only 200 mg.

If your diet contains the usual "average" calcium content of 300-500 mg a day, and you choose not to supplement this by using more milk products, you could get your recommended daily amount of 1500 mg of calcium by taking 3-4 extra-strength TUMS a day.

Vitamin D helps to ensure proper absorption of calcium. The recommended daily amount of vitamin D is 400 units. Most multiple vitamins contain this amount of vitamin D in each tablet, and milk is typically fortified with vitamin D as well. Taking more than the recommended daily amount of vitamin D is not helpful and may have side effects.

Weight-bearing exercise such as walking, jogging or weight-lifting helps to maintain the normal "balance" in bone remodeling and thus helps to preserve normal bone strength. Non-weight-bearing exercise such as swimming or bicycling is less helpful for osteoporosis prevention, although it is very helpful for cardiovascular fitness.

In addition, physical conditioning and balance training may be helpful in minimizing the risk of falling(10). A variety of simple precautions in the home are advisable for those who have difficulty with balance or limited mobility: (13)

Hormone replacement therapy refers to the use of two hormones, estrogen and progesterone, which are normally manufactured by the ovaries before menopause. After menopause, the production of these hormones drops dramatically. Hormone replacement can be thought of as a way of attempting to restore the normal hormone balance which is present before menopause.

Recent studies have found an increased incidence of breast cancer, heart attacks and strokes among women who have taken the commonly prescribed combination of Provera and Premarin (conjugated estrogen). Many are recommending against the use of these medications after menopause. If used at all, they should be used at the lowest effective dose and for brief periods of time. It is unclear if other hormonal therapies are safe.

Osteoporosis is defined in terms of a loss of bone density compared to the average value for young adults. Some degree of bone loss is considered "normal" with age, but when bone density falls below a certain level, bone fractures become more and more likely.

Evidence of osteoporosis can sometimes be seen on ordinary x-rays. On these x-rays, osteoporotic bones may appear more transparent than normal bones, or compression fractures of the spine may be seen. Osteoporosis needs to be fairly advanced to be detected in this way. Earlier diagnosis can be achieved through bone density scans such as "quantitative C.T." (computed tomography or CAT scan) or "DEXA" ("dual energy x-ray absorptiometry").

Does everyone need to have a bone density scan? No - but it may be advisable depending on your individual situation. Many physicians would argue that hormone replacement therapy, together with adequate calcium and exercise, is both the best prevention for osteoporosis and the best treatment for osteoporosis once it occurs. Because hormone replacement may be recommended for most women, not only because of osteoporosis but for other health reasons, a bone density scan may really provide no useful information. If your bone density is normal, your physician will still recommend hormone replacement as a way of ensuring that your bone density remains good. If you are found to already have osteoporosis, the recommendations will be the same: hormone replacement therapy, exercise, and calcium. However, for some women who have special risks or concerns, bone density testing may be helpful.(14)

Current treatments for osteoporosis include hormone replacement therapy, alendronate, etidronate, and calcitonin. All of these are used in combination with ensuring that proper amounts of calcium and vitamin D are being received. The cost of these medicines is generally covered by insurance companies if you have a prescription medicine benefit; some insurance companies require your physician to obtain authorization for the newer medicines before they will be covered. Other possible drugs are being studied. None of these other drugs have been approved yet by the FDA.

Hormone replacement acts by reducing bone resorption, and can increase bone density by about 5%. This is only a small increase, and emphasizes the fact that prevention is more effective than trying to reverse osteoporosis after it has already occurred. Still, even this small increase can cut the risk of having vertebral fractures by half.(11)

The combination of hormone replacement therapy, calcium and regular exercise is the best-studied treatment for osteoporosis once it has developed, and is still considered the standard treatment for women with postmenopausal osteoporosis.(5) Even if a woman already has had an osteoporosis-related fracture and has gone through menopause many years ago, there is still potential benefit to starting hormone replacement.(2) As noted above (see "Prevention" section above), the best time to start or stop hormone replacement is still unproven.

Alendronate and etidronate both belong to a class of drugs called "bisphosphonates." These drugs mainly act by reducing bone resorption. However, at high concentrations etidronate can actually interfere with bone formation. Because of this, etidronate has not been widely used for osteoporosis.

Alendronate, a newer drug, was just approved for treatment of osteoporosis in late 1995. It is not yet approved for prevention of osteoporosis. Alendronate has less potential than etidronate to interfere with bone formation, and has been found to be very effective in preventing bone resorption. It can increase the bone density of the spine by about 9%, and reduce the risk of a vertebral fracture by 48%(4). Alendronate is given as a single tablet every morning, which should be taken at least half an hour before eating or taking any other medicines (including calcium). It should be avoided in conditions marked by low blood levels of calcium or severe kidney disease. It generally causes very few side effects; some women experience stomach upset or irritation of the esophagus (the tube which brings food from the mouth to the stomach). It is very important to take the medicine properly in order to avoid this problem; be sure to take the medicine with a full 8 ounce glass of water, and do not lie down again afterward. Let your physician know if you have any stomach upset or heartburn after starting the medicine.

Because it is such a new drug, there is little information about alendronate's long-term safety, or how long it should be used. One potential source of concern is that alendronate remains present in bone for years, and it is unknown whether this could cause side effects later. Another disadvantage is that alendronate is more expensive than hormone replacement and does not have the other beneficial effects that hormone replacement can bring. Some insurance companies do not cover the cost of alendronate, or may require that the patient or physician apply for approval before receiving the medication. Its retail cost is about $58 per month.

Calcitonin is a hormone which is normally produced by the thyroid gland (a gland in the neck). Until 1995, calcitonin was only available in the form of injections. It cannot be given by mouth because it is destroyed by normal digestion. Now, it is also available in the form of a nasal spray; enough of the medication is absorbed through the thin lining of the nasal passages that it can enter the circulation and reach the bones.

Calcitonin also acts by reducing bone resorption. It does not have the potential to interfere with bone formation. Unlike alendronate, it does not remain stored in bone, but is rapidly cleared out of the body. It has been used in the form of injections for many years, and it appears very safe for long-term use. Its main advantage over other drugs for osteoporosis is that it has a pain-relieving effect, especially when used after an osteoporosis-related vertebral compression fracture. Unfortunately, it is less effective than either hormone replacement or alendronate. In general, it produces only a very slight gain in bone density of about 2%. It may reduce the risk of vertebral fracture by up to two-thirds(9), although the evidence demonstrating this is less impressive than with alendronate. Like alendronate, it is approved only for treatment of osteoporosis, not for prevention.

Calcitonin has few side effects; some irritation of the nose may occur. It is given in the form of one spray in the nose per day. It is the most expensive of the three options currently available, and like alendronate it does not have the other beneficial effects of hormone replacement therapy. Calcitonin's retail cost is about $70 per month; some insurance companies do not cover the cost of calcitonin, or may require that the patient or physician apply for approval before receiving the medication

Osteoporosis is an extremely common condition which can lead to painful and potentially dangerous fractures of bones in the spine and hip. The best "treatment" is really prevention. This should start at a young age, as maintaining good calcium intake and exercise habits in young adulthood may help build your bone strength to a higher level, reducing the effects of future bone loss. For women who are menopausal, hormone replacement therapy combined with calcium use and exercise represents the best way of preventing any further bone loss and reducing the chances of bone fracture.

In addition to the references listed below, you can find more information about osteoporosis through:

The Women's Health Resource Center, located at the Palo Alto Medical Clinic
300 Homer Avenue,
Palo Alto, CA 94301
Phone: (650) 614-3200
FAX: (650) 614-3232

The Health Library at Stanford, located at the Stanford Shopping Center
Co-sponsored by the Palo Alto Medical Foundation
Phone: (650) 725-8400

National Osteoporosis Foundation
1150 - 17th Street, NW, Suite 500
Washington, DC 20036-4603
Phone: (202) 223-2226
FAX: (202) 223-2237
Internet: http://www.nof.org/

1. American College of Physicians. Guidelines for counseling postmenopausal women about preventive hormone therapy. Annals of Internal Medicine, December 1992; vol. 177, pp. 1038-1041.

2. Ettinger B, Grady D. The waning effect of postmenopausal estrogen therapy on osteoporosis. New England Journal of Medicine, Oct. 1993; vol. 329, pp. 1192-1193.

3. Gambert SR and others. Osteoporosis: Clinical features, prevention and treatment. Endocrinology and Metabolism Clinics of North America, June 1995; vol. 24, pp. 317-371.

4. Liberman UA and others. Effect of oral alendronate on bone mineral density and the incidence of fractures in postmenopausal osteoporosis. New England Journal of Medicine, November 1995; vol. 333, pp. 1437-1443.

5. Lindsay R. The menopause and osteoporosis. Obstetrics & Gynecology, Feb. 1996; vol 87 (supplement), pp. 16S-19S.

6. Lufkin EG, Zilkoski M. Diagnosis and management of osteoporosis. American Family Physician Monograph #1, 1996.

7. NIH Consensus Conference. Optimal calcium intake. Journal of the American Medical Association, December 1994; vol. 272, pp. 1942-1948.

8. Ott SM. Estrogen therapy for osteoporosis - even in the elderly (editorial). Annals of Internal Medicine, July 1992; vol. 117, pp 86-87.

9. Overgaard K and others. Effect of salcatonin given intranasally on bone mass and fracture rates in established osteoporosis: a dose-response study. British Medical Journal, 1992; vol. 305, pp. 556-561.

10. Province MA, Hadley EC et al. The effects of exercise on falls in elderly patients. . Journal of the American Medical Association 1995; vol. 273, pp. 1341-1347.

11. Riggs BL, Melton LJ. The prevention and treatment of osteoporosis. New England Journal of Medicine, August 1992; vol. 327, pp. 620-627.

12. Speroff L. Postmenopausal hormone therapy and breast cancer. Obstetrics & Gynecology, Feb. 1996; vol 87 (supplement), pp. 44S-54S.

13. Tinetti ME, Speechley M. Prevention of falls among the elderly. New England Journal of Medicine 1989; vol. 320, pp. 1055-1059.

14. US Preventive Services Task Force. Screening for postmenopausal osteoporosis. In: Guide to clinical preventive services, Baltimore, Williams & Wilkins, 1996; pp. 509-517.

...from the Physicians at the Los Altos Center
Palo Alto Medical Foundation
370 Distel Circle
Los Altos, CA. 94022
(650-254-5200)