MENOPAUSE: Holding Back Osteoporosis

P eople tend to think of their bones as an unshakable foundation -- a strong and solid support system for the muscles and inner organs. However, our skeletal structure isn't solid at all, but composed of living, growing cells. Our bones depend on a dynamic balance of available minerals (such as calcium) and the hormones that control mineral absorption, to stay strong and healthy well into old age.

Osteoporosis, the condition that turns so many elderly women into smaller, shrunken, weakened versions of their former selves, is not inevitable. It is possible to grow older and still stand tall, walk confidently, retain strong bones, and enjoy a great deal of physical strength. Today, women can benefit from increasing medical knowledge about how to ward off this disease that weakens bone.

In fact, osteoporosis, the "silent thief" that robs us of bone strength, can often be prevented, or at least minimized, by simple improvements in nutrition and exercise before bone loss begins, generally around age 35. And even those already affected by severe bone loss, can take preventive measures to minimize the risk of disabilities.

Though 25 million Americans, mostly women, are affected by osteoporosis, surveys show that most (3 out of 4) women from ages 45 to 75 have never spoken to their doctor about the disease. This is a missed opportunity, because there is much you can do during and after menopause to protect yourself from this disease. This chapter outlines steps you can take to strengthen your bones and contribute to your better overall health and well-being as you get older.

The Framework: Understanding Bones

Bone cells, which store 99 percent of the calcium in our bodies, are continuously breaking down and building up, in a process called remodeling. The cells, which are interlaced with nerves and blood vessels, both collect calcium molecules from the bloodstream and release calcium back into circulation. The retained calcium adds to bone mass and keeps the skeleton strong.

As we age, the balance of retained versus lost calcium tends to tip in the wrong direction, with more calcium leaching out of our cells than is taken in. Losing a certain amount of bone mass is therefore a natural result of the aging process. However, after menopause, lower estrogen levels cause an accelerated rate of bone loss in most women, making them vulnerable to osteoporosis.

In osteoporosis, the bones become progressively more porous, making them more likely to break. Imagine osteoporatic bone as a honeycomb or Swiss cheese, and you can understand how the slightest trauma can cause debilitating bone fractures -- typically occurring in the hip, spine, and wrist.

Since the loss of crucial bone mass usually occurs without symptoms or pain, osteoporosis can go undetected for years -- until a fracture occurs. In young people, a broken bone usually heals itself in a month or two, but in old age, the process is slower and some fractures never fully heal.

A woman's lifetime risk of developing a hip fracture is equal to her combined risk of developing breast, uterine, and ovarian cancer. Hip fractures leave many women permanently disabled; and within 6 months following the injury, between 15 and 20 percent of patients will die because of a hip fracture and its complications. One in 3 women over 50 suffer vertebral fractures, which can lead to height loss and a stooped posture.

Hormones and Bone Strength

Our body balances the two processes of building new bone and removing old bone through the actions of a variety of hormones, including estrogen. Estrogen plays a dual role in bone metabolism: It facilitates the absorption of calcium from the blood into the bone and inhibits the loss of calcium from the bone. Bone density peaks in women about age 35. After this time, and especially when estrogen levels drop after menopause, bone loss exceeds new bone formation.

Normal estrogen levels help to ensure an adequate level of calcium in the blood, which, in turn, influences muscle and nervous-system functions. As estrogen levels decline, calcium blood levels can drop excessively, stimulating the production of another hormone called PTH. This hormone, which is secreted by the parathyroid gland, then triggers the leaching of calcium from the reservoir in the bones to correct the deficit in the blood, at the expense of bone health.

Bone loss accelerates after menopause, but varies considerably among individuals, for there is a wide variation in blood hormone levels among postmenopausal women. A woman can lose from one-half to 6 percent of her bone mass per year. This percentage may be even higher for women who experience surgical or chemically-induced menopause, in which the estrogen supply is abruptly cut down. By the time a woman is 80, she can easily have lost 40 percent of her bone mass. Once bone is lost it cannot be restored with tissue of equal strength or, as yet, be replaced.

Are You At Risk?

The risk of developing osteoporosis varies according to a number of factors, including sex, race, weight, and family history. People who enter midlife with light, thin bones have a smaller margin of bone mass that they can safely lose, and are therefore more vulnerable to bone disease.

Risk Factors You Cannot Control

Gender. Women generally have lighter, thinner bones than men. At age 35, men have 30 percent more bone mass than women, and they lose bone more slowly as they age. Because of the decrease in estrogen production that occurs during menopause, just being a woman puts you in the high-risk group for developing osteoporosis.

Race. Caucasian and Asian women have lower bone density than blacks by as much as 5 to 10 percent. Until recently it was thought that Caucasian women were at greatest risk for osteoporosis, but a recent large-scale study has found that Hispanic, Asian, and Native American women are at least as likely to have low bone mass as Caucasians. And one-third of African American women are also at risk.

Build. Having a delicate frame or weaker bones predisposes you to a higher fracture risk. Overall muscle tone also plays a role in the likelihood of sustaining an injury.

Onset of Menopause. Undergoing early menopause, naturally or surgically, increases your risk, because you will have reduced levels of estrogen for a longer period of time than you would with normal menopause. Because of the abrupt cessation of estrogen production that accompanies surgical menopause, women whose ovaries are removed (69 percent in one study) tend to show signs of osteoporosis within 2 years after surgery if no hormone replacement therapy is instituted. When medically possible, doctors recommend keeping your ovaries intact in order to maintain estrogen production, even if a hysterectomy (removal of the uterus) is necessary.

Heredity. Having a mother, grandmother, or sister with a diagnosis of osteoporosis or its symptoms ("dowager's hump" or multiple fractures) increases your risk. Body type, as well as a possible genetic predisposition to osteoporosis, can be passed from one generation to the next.

Controllable Factors

Exercise. The amount of exercise you get has a major impact on bone strength and growth. Bones tend to lose mass from inactivity; on the other hand, the mechanical stress of exercise -- especially weight-bearing exercise -- such as jogging, walking, and tennis -- has been shown to stimulate bone growth and improve strength.

Weight. Heavier women are at a smaller risk for osteoporosis since bone mass is positively affected by a slight excess of fat. Fat tissue converts other hormones to estrogen, even after menopause, and estrogen, as we know, aids with the absorption of calcium.

Childlessness. Never having children puts you at higher risk of bone loss because you won't experience the temporary surges of estrogen that accompany each pregnancy. These surges help to protect against osteoporosis later in life.

Calcium. Calcium is critical for building bones. You may have less bone mass than you should if you haven't been getting the recommended daily allowance of 1,200 milligrams per day throughout your life. Studies have shown that over 75 percent of American women get less than 800 milligrams of calcium a day; one out of four ingests less than 300 milligrams a day. For postmenopausal women, a high daily intake of 1,000 to 1,500 milligrams is recommended.

Smoking. Women who smoke generally experience menopause up to a year and a half earlier than nonsmokers, and thus face a longer period of estrogen deficiency and accompanying bone loss. Smoking also hampers efficient processing of calcium. Smokers have a higher rate of vertebral fractures than nonsmokers.

Alcohol. Consuming more than two alcoholic drinks daily can decrease calcium absorption. It also interferes with the vitamin D synthesis that helps the bones absorb calcium.

Medical Factors

Lactose Intolerance. This problem is caused by the deficiency of the enzyme, lactase, which aids in the digestion of milk products. Less milk means less calcium. Sixty percent of women with osteoporosis (but only 15 percent of the general population) are lactose intolerant.

Medications. Commonly prescribed steroids like cortisone and prednisone, thyroid for hypothyroidism, and phenobarbital or phenytoin (Dilantin) for seizures all interfere with the body's ability to absorb calcium from food or calcium supplements.

Medical Conditions. Women with anorexia, Celiac disease, (an intolerance of certain grain products), diabetes, chronic diarrhea, kidney, or liver disease are all more likely to develop osteoporosis.

Warning Signs of Osteoporosis

Loss of bone mass produces minimal symptoms, while it quietly eats away skeletal strength, making bones more susceptible to fracture. For some women, a fracture may therefore be the first outward sign of osteoporosis. A broken bone as the result of a minor jolt, such as a wrist fracture following a simple fall, is a good reason to suspect the development of osteoporosis. An x-ray of the fracture can confirm the extent to which the break was caused by deterioration of the bone. Fortunately, for many women there are other, less dramatic signs to watch for.

Backache

Because the vertebrae are the most common site of fracture in osteoporotic women, an early symptom of the disease is a persistent backache in the lower part of the spine. Sudden muscle spasms or pain in the back can occur while you are resting or doing routine daily tasks. This sudden pain is often caused by the spontaneous collapse of small sections of the spine that have been severely thinned or weakened over time. Unlike back pain due to other causes, this pain is localized and seldom spreads. Seeking treatment from an orthopedic specialist or gynecologist is important. Those who develop osteoporosis often begin to notice more severe backaches about 9 and a half years after their last menstrual period or 13 years after surgical menopause.

Height Loss

Spinal osteoporosis is rarely diagnosed until spinal bones have broken. These breaks occur at the weakest points of the spinal column -- places where the spine naturally curves. Women are often unaware that they have these compression fractures because they don't always cause prolonged or severe pain, or disability. However, one unmistakable warning sign is a loss of height, which is directly related to spinal crush fractures. This loss of 2-and-a-half up to as much as 8 inches occurs in the upper half of the body. You can and should watch for development of spinal osteoporosis by routinely measuring and recording your height.

"Dowager's Hump"

With a loss of height due to vertebral fractures comes distortion of the spine's normal curves. This can lead to the development of a "dowager's hump" -- a protrusion in the upper back and a shortening of the chest area, that leaves the ribs practically sitting on the pelvic region. One consequence is more difficulty in digesting food. Another is the impact on your appearance and self-esteem. This hunchback-like appearance is not a natural part of growing older or the result of poor posture; it is a clear indication of osteoporosis.

Tooth Loss

Tooth loss during midlife and the thinning of bones supporting the teeth is another indication of osteoporosis. The loss of tooth-bearing bone, called periodontal disease, is common among osteoporotic women. This bone thinning may be detected early by dental x-rays. To prevent periodontal disease, menopausal women should take extra care with their dental hygiene. This includes regular checkups and cleanings, brushing, and daily cleaning with dental floss or a Water Pik to retrieve food particles below the gum line.

Detecting Osteoporosis: Bone Density Screening

If you are at high risk for developing osteoporosis, or if you have already seen the early warning signs, discuss an evaluation of your skeletal health with your doctor. Ordinary x-rays do not detect osteoporosis until at least 30 percent of the bone is already lost and the disease has progressed much further than is healthy. But sophisticated technology is now available for earlier detection of bone loss, when it can still be stopped or perhaps reversed.

Several different methods of bone screening exist, all of which are painless, involve low-dose x-ray procedures, and range in cost from $75 to $250. Make sure you use a facil-ity that does bone density testing on a regular basis. Most large hospitals have the necessary equipment, and some even have special osteoporosis centers.

The current gold standard in bone density testing is dual x-ray absorptiometry (DXA), which can measure the spine, hip, or total body. It uses a minimal amount of radiation--about 10 percent of what you'd receive in a chest x-ray. The p-DEXA, a cheaper alternative found at many health fairs and malls, takes just 10 minutes. However, it measures bone density only at the wrist, not at the spine and hip, where fractures are most serious, and isn't particularly helpful in predicting such fractures. Be sure to discuss your test results with a qualified medical professional.

Routine screening for changes in bone density is still considered controversial. However, most experts agree that it's justified for women over 65 and others clearly at risk. It's also recommended if you've already been diagnosed with osteoporosis, so the doctor can monitor the effects of treatment. New biochemical tests, which measure bone breakdown products in blood and urine, can also be helpful in gauging your response to therapy. Such tests are not, however, reliable enough to provide a diagnosis.

Preventing Osteoporosis

While the effects of osteoporosis are most often seen in later life, your risk is determined by your level of bone mass at age 35. For this reason, it is important to build bone to its peak density prior to menopause. It is essential for young women to be aware of risk factors and to take steps to slow bone loss and improve bone remodeling. However, women in their 50s and 60s can also benefit by taking immediate anti-osteoporosis action. These steps focus on diet and exercise.

Calcium

Calcium, the primary component of bone tissue, is the key factor in maintaining bone strength. But if you diet, fast, or habitually eat little, your daily calcium requirements are probably not being met. In addition, excess consumption of protein, sodium, sugar, alcohol, and caffeine has been shown to decrease absorption of calcium from your diet. And a certain amount of calcium is lost naturally each day through excretion. Since your body needs calcium to function, it tries to compensate for all of these deficits by taking calcium from your bones.

This situation is further complicated as a woman reaches menopause. Since estrogen increases the absorption of calcium into your system, lower estrogen levels generally mean you need to take in more calcium. Your body will absorb calcium without estrogen -- but only at a lower rate.

Calcium needs vary according to unique requirements, but the bottom line is: To build bone mass, you need calcium. Studies have shown that women consume less than half of the calcium they need, pre-, peri-, and postmenopause. For a woman in her twenties, 650 milligrams of calcium may be adequate. But by menopause, most women need to ingest about 1,000 milligrams of calcium a day in order to prevent a loss of bone mass. Women in their 40s should consume 1,000 to 1,500 milligrams of calcium every day. After menopause, 1,500 milligrams daily is suggested for women who are not on hormone replacement therapy. Because your body can absorb only about 600 milligrams of calcium at a time, it is advisable to consume calcium-rich foods at separate sittings.

Ideally, calcium should come from a natural diet. Devising a plan to promote adequate calcium levels includes making calcium-rich foods -- such as dairy products, nuts, leafy greens, broccoli, rhubarb, salmon, sardines -- a regular part of your diet. Skim milk is just as valuable to your bones as high-fat whole milk.

Women who are lactose intolerant should consider using LactAid, which supplies the enzyme needed for proper digestion of milk products. Calcium-rich yogurt is another alternative because it is easier to digest than other dairy products.

Analyze your diet to learn how much calcium you are actually getting each day. Using the nearby chart can help you become more aware of calcium content in food, and aid you in shifting slowly to a new nutritional program.

Calcium supplements are recommended if you or your doctor feel your calcium needs are not being met through your diet. The recommended amounts are the same for dietary calcium: 1,000 to 1,500 milligrams of elemental calcium daily for women in their 40s, and 1,500 milligrams for postmenopausal women not on hormone replacement therapy. Don't overdo it. Excessive calcium can create other problems in the body, such as promoting kidney stones and hardening of the arteries.

The most important point about supplements is absorption. To be properly absorbed calcium supplements must dissolve quickly in the stomach. Yet in recent studies about half of the pills on the market failed to dissolve fast enough. You can test your brand of choice at home. Drop a tablet into a container with 2 to 4 ounces of vinegar, stirring twice. After 30 minutes the pill should have completely dissolved or disintegrated into fine particles. If not, change brands.

Calcium citrate is the preferred formulation of many doctors because it is easily absorbed (especially by older women who make less gastric hydrochloric acid), and does not need to be taken with meals. To ensure best absorption, calcium should be taken in two daily doses, preferably at breakfast and dinner. Also, for some women calcium needs to be accompanied by daily doses of vitamin D (see below) or it is likely to go unabsorbed.

Antacids have become a newly touted source of calcium. However, with alternatives like calcium-rich food and pure calcium supplements, there's reason to wonder why anyone would choose antacid tablets as a major source of calcium. Though antacids may be less expensive than supplements, many contain aluminum, which can actually cause your body to lose calcium. (Two popular brands, Tums and Titralac, are aluminum-free, however.)

If you need to take an antacid for its intended purpose, there's nothing wrong with taking one that contains calcium. However, taking antacids solely for their calcium content is not recommended. Taken five to six times a week, they may be harmless; but in excessive amounts they can cause constipation and may lead to the formation of kidney stones and other urinary problems. In addition, certain pre-existing medical conditions can be aggravated by antacids, including colitis, stomach or intestinal bleeding, irregular heartbeat, and kidney disease.

Other Vitamins and Minerals

Vitamin D is essential to ensure adequate supplies of calcium in your body because it not only helps the body absorb calcium but also promotes its uptake into the bone. But very few foods in our diet are rich in vitamin D so you may be at risk of a deficiency. It's important to monitor your intake of this crucial vitamin, or the efforts you make to get adequate supplies of calcium may be futile.

The recommended daily dose of Vitamin D is 400 international units (IU). If you do opt to get your daily dose from supplements, be aware that amounts over 1,000 IU a day can interfere with calcium absorption. Also, because vitamin D is stored in the body for long periods of time, megadoses can be toxic. Most women need supplements of no more than 400 IU daily -- and only during winter in cloudy regions at that. For women over 65 years of age, supplements of 800 IU per day are usually the most that's recommended.

Vitamin D is present in such foods as egg yolk, certain fish, fish liver, and butter. Fortunately, it is also added to milk, bread, cereals, and other foods. An 8 ounce glass of milk contains 100 IU of vitamin D. Exposure to sunshine for about 15 minutes a day can also trigger the body's formation of needed vitamin D.

Magnesium is an important mineral for strong teeth and bones because it helps your body utilize calcium and vitamin D. Physicians agree that your daily magnesium dosage should be at least half the amount of calcium you consume on a daily basis -- for example, 600 milligrams of magnesium to 1,200 milligrams of calcium. Provided you eat a balanced diet, however, your chances of having a magnesium deficiency are very low.

Phosphorus is a mineral necessary to metabolize calcium, and should be consumed in amounts equal to your calcium intake. However, most Americans get too much phosphorus by eating excessive quantities of red meat, white bread, processed cheese, and soft drinks. Excess phosphorus, like excess vitamin D, actually accelerates bone demineralization and increases urinary calcium levels. To keep your phosphorous level in line, avoid consuming large quantities of foods labeled as containing sodium phosphate, potassium phosphate, phosphoric acid, pyrophosphate, or polyphosphate.

Exercise and Posture

Physical activity affects bone strength because bone mass increases or decreases in response to the demands placed on it. Developing and maintaining good exercise habits can significantly reduce your risk of age-related bone fracture. Women who work out regularly have a bone density that is often 10 percent higher than that of women who do not. Research also shows that just 3 hours a week of weight-bearing exercise can decrease bone loss by as much as 75 percent. In addition, exercise increases muscle tone and mass, which serves to cushion and support bones and makes falls due to unsteadiness less likely.

Weight bearing exercises, which work the muscles against gravity, are the key to creating positive stress on your bones. These exercises includes jogging, aerobics, dancing, and tennis. Walking is also an excellent way to strengthen the back, legs, and stomach muscles. Though swimming and biking provide less positive bone stress, these exercises do help to increase muscle tone. Strength training exercises with free weights or machines offer almost no beneficial effect on the bones, but are still well worth pursuing. By increasing steadiness and strength, they can help prevent the falls that often result in fractures.

Just as exercise has profound effects on the strength of bone, the way you sit and stand everyday affects the way your bones shape themselves. If you slouch, your bones will grow to conform to that curvature. If you sit and stand with an erect posture, your bones will have a tendency to grow straight.

Hormone Replacement Therapy

Long term hormone replacement therapy (HRT) after the onset of menopause improves calcium absorption and has been shown to prevent osteoporosis in 75 to 80 percent of women. It is especially effective in women with chemically or surgically induced menopause. Employing products such as Premarin, Premphase, or Prempro, HRT is usually continued for 8 to 10 years or more after menopause, the time when women experience bone loss at an accelerated rate. Evista, the new drug with estrogen-like effects on the bones, provides an additional option. In order for the medications to be fully effective, a woman's calcium, vitamin D, and magnesium intake should be at recommended levels.

The medical community is still debating the best dosage and length of time for HRT. To make an informed decision about whether you should consider this therapy, see the next chapter.

Bone-Building Medications

One alternative to hormone replacement therapy is the bone-strengthening drug alendronate (Fosamax), now approved for the prevention and treatment of osteoporosis in postmenopausal women. This once-a-day pill has been shown to increase bone mass density in the spine and the hip, thus decreasing fracture risk. To maximize absorption of the pill -- and minimize the risk of irritation to the throat and upper digestive tract -- alendronate must be taken with a full glass of water on an empty stomach upon rising in the morning. It's necessary to wait 30 minutes after taking the pill before eating breakfast.

Another alternative, calcitonin (Calcimar, Miacalcin), is a naturally occurring hormone involved in bone metabolism. It slows bone loss and increases spinal bone density, and may relieve the pain associated with fractures. It is available as an injection or a nasal spray.

Coping with Osteoporosis

Once osteoporosis has been diagnosed, treatment usually consists of vitamin D, adequate calcium intake, and perhaps estrogen supplements or a bone-building medication.

If you already have osteoporosis, your doctor is also likely to advise appropriate exercise regimens that strengthen, but do not fracture, the bones. Exercise will not cure osteoporosis, but it can help you preserve the bone mass you do have, strengthen your back and hips, maintain flexibility, and steady your gait. Within only 6 months, a regular exercise program can reduce your risk of bone fractures. The best program is one you can continue on a regular basis.

In addition to specific treatment programs, you may need to make other adjustments in your daily life to reduce your risk of sustaining an injury. The following recommendations are made by the National Osteoporosis Foundation:

• Wear sturdy, low-heeled, soft-soled shoes; avoid floppy slippers and sandals.
• Ask your doctor whether any medications you are taking can cause dizziness, light-headedness, or loss of balance. If so, is there anything you can do to minimize these side effects.
• Minimize clutter throughout the house.
• Secure all rugs; avoid using small throw rugs that can slip and slide.
• Remove all loose wires and electrical cords that can cause tripping.
• Make sure treads and handrails are installed on staircases and remain secure.
• Keep halls, stairs and entries well lighted.
• Use nightlights in the bedroom and bath.
• In the bathroom, use grab bars and nonskid tape in the shower or tub.
• In the kitchen, use nonskid rubber mats near the sink and stove.
• Avoid using slippery waxes; watch out for wet floors; clean up spills immediately.
• When driving, wear seat belts and adjust seat properly.