Bone Health and Osteoporosis
Bones are the supporting structure of our body, giving us our height, posture, stature, and strength. Strong, healthy bones are important to athletic activity, as they form the frame and skeleton for muscles. Having a solid skeleton allows better muscle strength and more efficient movement. Bone is a constantly changing tissue that grows and remodels; this process is known as "bone turnover." Bone turnover is regulated by hormones, which maintain the delicate balance of bone breakdown and bone rebuilding. The most rebuilding occurs early in life, as the body creates the strongest foundation of bones until age 30.After age 30, there is a natural slowdown in buildup of bone. Over time, bones become naturally thinner. This process occurs much more dramatically in women. Unfortunately, being female is a risk factor for having weaker bones. There are also other risk factors that can compromise a woman's strong skeleton, making bones thinner and weaker. Osteoporosis, the condition of thin, weak bones and increased risk of fractures, is known as a "silent disease" because it is sometimes not diagnosed until several fractures have already occurred. Thin bones can also occur in young, athletic girls and women, causing stress fractures, which can lead to muscle, tendon, and ligament problems and increase the risk of other fractures. Younger girls and women who have frequent stress fractures have a much greater risk of osteoporosis and associated dysfunctional posture and serious fractures later in life.
Women of all ages should make bone health an important concern to avoid the pain, fractures, and time lost from athletic and life activities that occurs with osteoporosis. Strengthening your bones will help guarantee a future of strength, mobility, and reduced hospital and doctor visits! It is very important to do the best you can to protect your bones. A preventive, proactive strategy as outlined here can help you meet this goal.
Osteoporosis
Osteoporosis is the medical term for the disease process of having bones that are fragile and more easily breakable. Osteoporosis bones look holey and thin under the microscope, similar to fragile sheer lace, rather than the tight-knit pattern of healthy bone. Osteoporosis bones have less dense structure with less hard strong calcium to hold them together and provide strength and stability.
The most common osteoporosis fractures are of the hip, spine, and wrist; these often occur in older women and can be debilitating, painful, and life-changing. Not only do the fractures themselves cause problems as immediate and sometimes ongoing pain and disability, but there can be other medical complications as well, including blood clots, pneumonia, constipation, and impaired nerve function. The cost of treating fractures due to osteoporosis, including surgery, hospitalization, and medical complications, is high. Because bones in osteoporosis are so weak, fractures can also happen without falling. For these reasons, osteoporosis has become a serious issue for medical clinicians and researchers.
Common Areas of Fractures Due to Osteoporosis and Their Consequences
- Wrist-motion and use might never be the same; two to four months to heal
- Vertebra (spine)-very painful, can occur without a fall; two to four months to heal with long-term pain
- Hip-requires surgery and hospitalization; can be very serious; full recovery takes 6 to 12 months
Long-Term Negative Consequences of Osteoporosis
- Fractures
- Dysfunctional and painful posture
- Surgery
- Loss of lung volume and breathing capacity
- Disability
- Poor endurance
- Pain
- Medical costs
- Loss of strength
- Hospital stays
- Loss of height
- Other medical complications
Osteoporosis is due to a combination of factors. Older age and female sex are significant risk factors; after menopause, the risk of osteoporosis becomes much higher. Osteoporosis is also more likely in people with family members who have osteoporosis, as well as in thin, Caucasian, and Asian women. Girls and women who have a history of eating disorders including frequent dieting and poor nutrition are more likely to get osteoporosis. High-protein and low-calcium diets along with other bad lifestyle choices such as smoking and drinking excessively contributes to osteoporosis as well. Also, women who are inactive or do not participate in regular weight-bearing and resistive exercise are more likely to develop osteoporosis. Having a diagnosis of osteoporosis means your risk of fracture is four times greater than if you do not have it.
Risk Factors for Osteoporosis Fractures
(Charts adapted from the National Osteoporosis Foundation)
| Permanent | Modifiable |
|---|---|
| Having a fragility fracture* as an adult | Cigarette smoking |
| A close relative with a fragility fracture* | Not having a period for more than six months |
| Caucasian or Asian race | Diet low in calcium |
| Postmenopause | More than two alcoholic drinks per day |
| Female gender | Falling, poor balance |
| Lifelong history of absent periods | Low levels of activity |
| Bad eyesight (increasing fall risks) | Frail health |
| Early menopause (before age 45) | Weak muscles |
| Lifelong history of eating disorders | Hormone imbalance |
| Chronic health problems | Low-calorie or poor nutrition diet |
*Fragility fracture = a fracture occurring from a fall from standing height or lower
There are also certain medical conditions that make osteoporosis more likely, due to both the underlying disease and also due to side effects of medications for treatment. The most common medications that directly affect bone health are corticosteroids, often used to treat asthma, arthritis, and immune disorders. Women with hormone imbalances such as Cushing's disease, hyperparathyroidism, hyperthyroidism, and genetic sex hormone deficiency are also at higher risks. Also, diseases that cause disabilities to limit walking such as multiple sclerosis and spinal cord injuries can lead to thinning bones.
Risk Factors for Osteoporosis That Cannot Be Changed
| Factor | Explanation |
|---|---|
| Older age | With age, bone density decreases. |
| 15 percent of women in their 50s have osteoporosis; 50 percent of women in their 80s have it. | |
| Female sex | Women have a much greater risk than men. |
| Women have thinner lighter bones, less muscle mass to protect them, and are hormonally more susceptible. | |
| Family history | Genetics pre-programs a body to be susceptible to certain things such as osteoporosis and greater rate of fractures. |
| Small size | Small, thin people are more at risk. |
| Muscle and fat protect and strengthen bones. | |
| Other medical risks | Certain medical problems such as hypothyroid and hormonal imbalances lead to higher risks of osteoporosis. |
Risk Factors for Osteoporosis That Can Be Changed
| Factor | How |
|---|---|
| Low activity level | Those less active and less on their feet have weaker bones. |
| Bones get stronger the more they are used. | |
| Low-calcium diet | Calcium is necessary for bone formation; it is the basic substance of bones. |
| Smoking, excess alcohol | Excess alcohol and tobacco interfere with bone formation. |
| Not having periods during | Estrogen is needed for the delicate balance of hormones |
| reproductive years | to form and maintain bones. |
| High-protein diets | High-protein diets interfere with calcium absorption. |
The Role of Hormones
Estrogen is important to the bones' ability to absorb and retain calcium, maintaining structure and protecting bones from becoming weak. A regular menstrual period is the result of estrogen circulating through the body; therefore, women who do not get their periods regularly are at increased risk of having osteoporosis secondary to decreased estrogen levels. After menopause, estrogen levels decrease as well, contributing to the increased risk of osteoporosis. This is one reason estrogen supplements have been prescribed after menopause (other reasons include reducing uncomfortable side effects of menopause such as hot flashes). However, estrogen supplements only prevent osteoporosis and risk of fractures, they do not treat it. Although women who take estrogen after menopause actually do develop less fractures, the Women's Health Initiative, a groundbreaking study concluded in 2002, revealed that after five years of continuous treatment with hormone supplements, women can have slightly higher risks of breast cancer, blood clots, stroke, and uterine cancer. Therefore, prescribing estrogen supplements for postmenopausal women is no longer the treatment of choice. (If you are taking estrogen supplements after menopause, they should be at the lowest doses possible and taken along with progesterone to preserve a more natural body hormone balance; also, try not to take them for more than five years.)
Testing and Diagnosis
Testing is easy, painless, and risk-free, as only minor levels of radiation are used; the greatest risk is not having it done. A true diagnosis of osteoporosis can only be made after a bone density test has been done, specifically the DEXA test, as mandated by the World Health Organization. This is the "gold standard" test for bone mineral density. It is a safe test that uses very low-dose radiation-much less than a standard x-ray. It measures density at the hip, spine, and wrist. Testing is ordered by a medical doctor and is usually done by a technician; insurance covers the test every two years in women who have reached menopause and in women who have had stress or multiple fractures.
Currently, 40 percent of post-menopausal women in the United States have osteoporosis; the number might actually be greater if more women were tested.
Ask your doctor for a bone density test if you have reached menopause or have had more than three fractures over your lifetime (not due to a serious accident).
Terms and Fracture Risk Increase
- Osteoporosis = four times greater risk of fracture
- Osteopenia = two times greater risk of fracture
World Health Organization Classifications of Osteoporosis
| Term | Definition | What It Means | Recommended Tests |
|---|---|---|---|
| Osteoporosis | T score less than -2.5 | Bones are four times more likely to fracture | Bone density testing two years after medications and treatment started |
| Osteopenia | T score between -1 and -2.5 SD | Thin bones are heading toward osteoporosis | Bone at density testing least every three years |
DEXA testing is recommended at least once for all women after menopause and at all ages for women who have had more than one fracture not due to an injury. You should always have your bone density testing done at the same facility, as different machines can give different results. Standard follow-up is done one to two years after treatment begins, and every two to three years if you have osteopenia. For those with normal bone density measurements, repeat testing should be done at least once after three to four years. Other types of testing, such as heel ultrasound or wrist or finger screening, are less expensive, take less time, and have less radiation, but are much less comprehensive and do not allow for accurate evaluation of overall body bone density. These other types of testing are not recommended for women with risk factors, unless DEXA testing is not available.
Tests to Evaluate Bone Health
| Type of Test | How It Is Done | Purpose |
|---|---|---|
| DEXA | A scan is taken of your body | The gold standard for bone density; it measures density at your spine and hip and establishes a diagnosis of osteoporosis |
| PDXA | A scan is taken of your wrist, finger, or heel | Bone density at specific site tested; does not necessarily correspond to hip or spine |
| QUS (Quantitative Ultrasound) | An ultrasound scan is taken of the heel and shin | Determines bone density of the heel, whichcorresponds closely to the hip. Used as a convenient, quick screening tool |
| X-ray | A picture of your bones is taken | Evaluates fractures and other bone problems; not a screening tool for osteoporosis |
| Bone scan | Dye is injected into your blood; hours later, you have a scan taken | Evaluates a possible stress fracture or other problem with the bone; not a screening tool for osteoporosis |
| MRI, CT scan | A scan is taken (MRI more comprehensive) | Evaluates whether you have a stress fracture or other problem in your bone; not a screening tool for osteoporosis |
| Blood tests | Blood is drawn | Evaluates hormones and indicators of bone turnover helpful to understand cause |
| Urine test | Urine sampled | Measures calcium lost in urine |
| Bone biopsy | A needle is put into the | Evaluates abnormal bone |
Doctors who diagnose and treat osteoporosis can have medical degrees in various specialties; this is a reflection of the many aspects of health that thin bones can affect. For more complicated cases and when frequent stress fractures or fall fractures occur in younger girls or women, referral to an endocrinologist (hormone specialist) is recommended, as these are medical specialists who are most qualified to evaluate and treat osteoporosis. If you are in your teens or reproductive years and have had more than three fractures or absent periods, a bone density test should be done to screen for osteoporosis or osteopenia. If there is evidence of decreased bone density, it is recommended that you go to an endocrinologist to evaluate and correct the problem now to prevent future problems. For osteoporosis after menopause, your primary care doctor, gynecologist, orthopedist, physiatrist, or rheumatologist may manage your treatment.
Treatment
The ultimate goal of diagnosis and treatment of osteoporosis is to reduce the number of fractures. Because bone density is the most reliable measure of osteoporosis, treatment is focused on increasing bone density. Bone strength is directly related to density, and ultimately, the stronger the bone, the less likely it will fracture. Bone strength also improves with proper diet and exercise. Hormones and genetics also influence bone strength. Treatment of osteoporosis is most effective using a combination of medications, calcium, vitamin D, weight-bearing exercise, and lifestyle and dietary modifications.
The most effective osteoporosis medications to date are the bisphosphonates, marketed as Fosamax and Actonel. Taken once weekly, these drugs are the most likely to increase bone density, decrease fracture risk, and reduce bone breakdown. Bisphosphonates function by interfering with the natural process of bone resorption and have been shown to reduce spine fracture risk by 30 to 50 percent and hip fracture risk by 24 to 50 percent. Estrogen supplements can prevent the development of osteoporosis and some fractures but are not recommended specifically for treatment, nor are they recommended for more than five years after menopause. Other types of drugs that are also used are described in the following chart. Consult with your doctor if you are taking some of the less-effective medicines, especially if you have a definite diagnosis of osteoporosis.
Medications Used to Treat and Prevent Osteoporosis, in Increasing Order of Effectiveness
| Drug Type (Common name) | Function | Side Effects | Effectiveness |
| Calcitonin (Miacalcin), nasal spray; also can be injected | Helps bones absorb calcium; also helps with pain of vertebral (spine) fractures | Itchy or runny nose, pain from injection | More effective five years after menopause; minimal effect on bone density or strength |
| Estrogen, oral or patches (Estraderm,Climera, Premarin) cyclic estrogens with progesterone (Premphase), estrogen with progesterone (Prempro, Femhrt, Activella) | Allows bones to absorb and retain calcium better | Blood clots, stroke; some women at greater risk of breast cancer; mood changes, depression, weight gain, breast tenderness | Prevention only: although the number of hip and spine fractures are reduced, these are not recommended for treatment of osteoporosis |
| Selective estrogen receptor modulator, (SERM) Raloxifene, Evista | Tissue-specific estrogens used in women who have had breast cancer or other risk factors with estrogen; prevents breast cancer in some women | Similar to estrogen side effects | Recent studies do |
| not show that these reduce the risk of hip and other fractures; more preventive than treatment | |||
| Bisphosphonates, Fosamax (Alendronate Sodium), Actonel (Risedronate Sodium) | Decreases bone breakdown | Irritation of the esophagus; needs to be taken first thing in the morning with a full glass of water; remain upright for 30 minutes | Extremely effective; reduces all fractures vertebral (spine) to fractures by 30 to 50 percent and the the incidence of hip fractures by 24 to 50 percent |
| Parathyroid hormone, Forteo (teriparatide) | Increases bone formation and decreases resorption | Needs to be injected daily; will often be used in combination with drugs; may cause cancer | Potential to increase bone formation and reduce fractures by 60 percent; not yet widely available or tested |
Nutrition is very important, as bone growth and strength cannot occur without calcium, the building block of bone. Vitamin D and magnesium also play an important role. Vitamin D helps the body retain calcium and prevents it from being excreted out of the body via the kidneys. Bone specialists recommend taking 1,300 to 1,500 mg of calcium in two or three divided doses with two of the doses taken in the evening (one with dinner, one before bed). A multivitamin containing 400 IU of vitamin D should also be taken with the evening meal. There are also other trace minerals involved in bone formation, including magnesium; these are covered by taking your multivitamin daily, a recommended habit for everyone.
When totaling your calcium and vitamin D intake, include food and drink sources so you do not overdo the amounts. Adding your total calcium milligram is easy by reading labels-add a zero to the percent daily value of calcium listed on the food label to easily calculate the mineral content. Supplement to total 1,500 mg. For example, if you have eaten three servings of dairy products, each containing 30 percent the "daily value" (%DV) of calcium (such as milk, cheese, and calcium-fortified orange juice), your total calcium intake through foods is 900 mg. So on this day, you only need to take one 600 mg supplement of calcium. Daily vitamin D needs are covered in your multivitamin and the milk products you have consumed. It is not recommended to take more than 2,000 mg of calcium or 800 IU of vitamin D daily. Also, do not take vitamin A supplements if you have osteoporosis; this has been shown to increase fracture risk.
In women who have osteoporosis, excess salt, high-protein diets, alcoholic drinks, and carbonated drinks should be kept to a minimum, as these can interfere with the body's calcium absorption and retention. Caffeine can also increase calcium loss, but this effect is minimal, unless you are also a smoker. Smoking is detrimental to the bones and should be stopped!
Exercise improves bone strength, just as it improves muscle strength. Our bodies work as hard as possible to positively respond to the healthy stress of exercise, resulting in not just stronger muscles and lung and heart function, but also stronger bones. The proven way to strengthen bones is with weight-bearing exercise, brisk walking, mountain biking, stair climbing, soccer, basketball, racket sports, and hiking. The greater the weight-bearing impact, the greater the effect. (Gymnasts and runners tend to have very strong bones, despite their thin frames.) Resistive weight training has also been shown to positively stress bones and make them stronger.
It is recommended to use a combination of these weight-bearing exercises for the most effective increase in bone strength, ideally doing weight-bearing exercise for at least 20 to 30 minutes each day, along with upper body strength training three times a week for 20 minutes. Lower body strength training should be done if your exercise program is not weight bearing such as swimming, cycling, or kayaking. Be aware that exercise can also be overdone, causing bones to negatively respond to the excess stress with stress fractures; therefore, impact or intense weight training is not recommended for more than one hour each day, unless you are a highly trained athlete.
Prevention
The good news is that for most women, osteoporosis can be prevented. The best things you can do to prevent osteoporosis is do regular weight-bearing and resistive exercise; eat a healthy diet with at least 1,200 mg calcium daily; limit carbonated drinks, salt, and excess protein; and don't smoke. Additional preventive measures are limiting alcohol to no more than 10 drinks a week and having a bone density test if you have had more than three fractures in your life or have gone through menopause. If you are of reproductive age, make sure you are having regular periods.
Calcium Intake
Research suggests that 90 percent of American women do not get enough calcium.
Calcium is a mineral your body needs in daily supply, because it cannot be made by the body and is cycled out of the body through nails, hair, skin, sweat, urine, and stool. Unless you are a person who loves dairy products and regularly eats four servings a day of milk, cheese, or yogurt, or regularly eats calcium-fortified foods , you must take supplements. Most women must make a conscious effort to eat 1,200 to 1,500 mg calcium a day, because the majority of American women's diets do not even contain half the recommended amount! The bonus: Calcium eases symptoms of PMS, prevents muscle cramping, and has also been found to help with weight management.
Daily Recommended Calcium Intakes*
| Age | Amount mg/day |
| Birth to 6 months | 210 |
| 6 months to 1 year | 270 |
| 1 to 3 | 500 |
| 4 to 8 | 800 |
| 9 to 13 | 1,300 |
| 14 to 18 | 1,300 |
| 19 and over | 1,200 |
| Pregnant and lactating | 1,300 |
| Athletic girls and women | 1,500 |
*Adapted from the National Osteoporosis Foundation
Calcium Supplements
Calcium, a mineral element, is only available to our body in combination with other substances called calcium compounds. The best compounds are those found naturally in dairy products and certain foods, such as broccoli, almonds, and canned salmon. Supplements are usually one of three compounds: calcium carbonate, calcium phosphate, or calcium citrate. The RDI, or daily recommended milligrams of calcium, refers to the amount of calcium in the supplement compound (not total milligrams of compound), also called "elemental calcium." When reading labels, be sure to look for the amount of "elemental calcium" in the supplement compound. Another way to determine the actual calcium of a food source is to take the "percent daily value" (%DV) listed on the food label and add a zero (the FDA's recommended daily intake of calcium is 1,000 mg). For example, one cup of milk has 30%DV of calcium; this equals 300 mg elemental calcium.
The type of calcium compound and the ease of its breakdown by the digestive system affects how well it reaches the bones. In order for calcium to become available to the bones, it must be absorbed; this occurs best in a chewable or liquid form. Calcium is also absorbed best when taken in smaller doses of 500 mg or less at a time. The two most common compounds are calcium citrate and calcium carbonate. Calcium carbonate is found in stomach-soothing tablets such as Tums and offers a cheap and tasty way to get your calcium supplement. Calcium carbonate is best absorbed with food. Calcium citrate can be taken at any time and is recommended for women who also take iron supplements, as carbonate can interfere with iron absorption. (Otherwise, the calcium and iron supplements should be taken separately.) Try to take "purified" forms of calcium, rather than "natural" ones. Oyster shell, bonemeal, or dolomite preparations or many "natural" preparations are not recommended, as they can contain high levels of lead, magnesium, or aluminum, which can be dangerous.
Because of the inconsistencies of the amount of calcium that actually gets absorbed by the bones, it is recommended to slightly exceed the recommended dose and aim for 1,500 mg daily. This is especially true for active athletic girls and women, as calcium is lost through sweat. If your diet is rich in calcium, taking one 300 to 600 mg supplement or taking a multivitamin that contains calcium daily is still recommended. Vegetarians and women who do not eat dairy must take supplements or eat calcium-fortified foods to total at least 1,200 mg a day.
To test absorption of your calcium supplement, place one tablet in a glass of half vinegar, half water. If it dissolves within 30 minutes, it is recommended as an easily absorbed supplement.
Tips to Help Your Body Absorb Calcium Most Effectively
- Divide your total dose if you need to supplement more than 600 mg; take half with dinner and half before bedtime.
- Make sure it is an absorbable form (see above).
- Do not take it with iron unless you are also taking vitamin C or calcium citrate.
- Calcium carbonate should be taken with food.
- Take calcium with or after a snack or meal.
- Avoid "natural," aluminum, oyster shell, or bonemeal supplement types.
- Look for "purified" on the label.
- Select a chewable or liquid form.
- Experiment with different flavors to find one you like.
From The Active Woman's Health and Fitness Handbook by Nadya Swedan. Copyright © 2003 by Nadya Swedan. Used by arrangement with Perigee, a member of Penguin Group (USA) Inc.
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