Osteoporosis Diagnosis

February 2016

This publication is for people who have osteoporosis, their families, and others interested in learning more about the disease. It describes osteoporosis and its impact and contains information about the causes, diagnosis, and treatment of this disease. This publication also describes current research efforts supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and other components of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH). Also covered are risk factors for osteoporotic fractures, ways to prevent the disease and its progression, and how people with the disease can reduce their risk of future fractures. If you have further questions, you may wish to discuss them with your doctor or seek additional information from the sources listed at the end of this publication.

Defining Osteoporosis

Osteoporosis is a disease marked by reduced bone strength leading to an increased risk of fractures, or broken bones. Bone strength has two main features: bone mass (amount of bone) and bone quality. Osteoporosis is the major underlying cause of fractures in postmenopausal women and the elderly. Fractures occur most often in bones of the hip, spine, and wrist, but any bone can be affected. Some fractures can be permanently disabling, especially when they occur in the hip.

Osteoporosis is often called a “silent disease,” because it usually progresses without any symptoms until a fracture occurs or one or more vertebrae (bones in the spine) collapse. Collapsed vertebrae may first be felt or seen when a person develops severe back pain, loss of height, or spine malformations such as a stooped or hunched posture. Bones affected by osteoporosis may become so fragile that fractures occur spontaneously or as the result of minor bumps, falls, or normal stresses and strains such as bending, lifting, or even coughing.

Many people think that osteoporosis is a natural and unavoidable part of aging. However, medical experts now believe that osteoporosis is largely preventable. Furthermore, people who already have osteoporosis can take steps to prevent or slow further progress of the disease and reduce their risk of future fractures. Although osteoporosis was once viewed primarily as a disease of old age, it is now recognized as a disease that can stem from less than optimal bone growth during childhood and adolescence, as well as from bone loss later in life.

Who Has Osteoporosis?

In the United States today, more than 53 million people either already have osteoporosis or are at high risk due to low bone mass. Osteoporosis can occur at any age, although the risk for developing the disease increases as you get older.

Osteoporosis is most common in non-Hispanic white women, but the disease affects many older Americans of any race or sex.

In addition to the financial costs, osteoporosis takes a toll in terms of reduced quality of life for many people who suffer fractures. It can also affect the lives of family members and friends who serve as caregivers.

Of all fractures, hip fractures have the most serious impact. Most hip fractures require hospitalization and surgery; some hip fracture patients require nursing home placement. One in three adults who lived independently before their hip fracture remains in a nursing home for at least a year after their injury. About one in five hip fracture patients over age 50 die in the year following their fracture as a result of associated medical complications. Vertebral fractures also can have serious consequences, including chronic back pain and disability. They have also been linked to increased mortality in older people.

Bone Basics

Bone is a living tissue that supports our muscles, protects vital internal organs, and stores most of the body’s calcium. It consists mainly of a framework of tough, elastic fibers of a protein called collagen and crystals of calcium phosphate mineral that harden and strengthen the framework. The combination of collagen and calcium phosphate makes bones strong yet flexible to hold up under stress.

Bone also contains living cells, including some that nourish the tissue and others that control the process known as bone remodeling. Throughout life, our bones are constantly being renewed by means of this remodeling process, in which old bone is removed (bone resorption) and replaced by new bone (bone formation). Bone remodeling is carried out through the coordinated actions of bone-removing cells called osteoclasts and bone-forming cells called osteoblasts.

During childhood and the teenage years, new bone is added to the skeleton faster than old bone is removed or resorbed. As a result, bones grow in both size and strength. After you stop growing taller, bone formation continues at a faster pace than resorption until around the early twenties, when women and men reach their peak bone mass, or maximum amount of bone. Peak bone mass is influenced by various genetic and external, or environmental, factors, including whether you are male or female (your sex), hormones, nutrition, and physical activity. Genetic factors may determine as much as 50 to 90 percent of bone mass; environmental factors account for the remaining 10 to 50 percent. This means you have some control over your peak bone mass.

After your early twenties, your bone mass may remain stable or decrease very gradually for a period of years, depending on a variety of lifestyle factors such as diet and physical activity. Starting in midlife, both men and women experience an age-related decline in bone mass. Women lose bone rapidly in the first 4 to 8 years after menopause (the completion of a full year without a menstrual period), which usually occurs between ages 45 and 55. By age 65, men and women tend to be losing bone tissue at the same rate, and this more gradual bone loss continues throughout life.

Causes of Osteoporosis

Less than optimal bone growth during childhood and adolescence can result in a failure to reach optimal peak bone mass. Thus, peak bone mass attained early in life is an important factor affecting your risk of osteoporosis in later years. People who start out with greater reserves of bone (higher peak bone mass) are less likely to develop osteoporosis when bone loss occurs as a result of aging, menopause, or other factors. Other causes of osteoporosis are bone loss due to a greater than expected rate of bone resorption, a decreased rate of bone formation, or both.

A major contributor to bone loss in women during later life is the reduction in estrogen production that occurs with menopause. Estrogen is a sex hormone that plays a critical role in building and maintaining bone. Decreased estrogen, whether due to natural menopause, surgical removal of the ovaries, or chemotherapy or radiation treatments for cancer, can lead to bone loss and eventually osteoporosis. After menopause, the rate of bone loss speeds up as the amount of estrogen produced by a woman’s ovaries drops dramatically. Bone loss is most rapid in the first few years after menopause but continues into the postmenopausal years.

In men, sex hormone levels also decline after middle age, but the decline is more gradual. These declines probably also contribute to bone loss in men after around age 50.

Osteoporosis can also result from bone loss that may accompany a wide range of disease conditions, eating disorders, and certain medications and medical treatments. For instance, osteoporosis may be caused by long-term use of some antiseizure medications (anticonvulsants) and glucocorticoid medications such as prednisone and cortisone. Glucocorticoids are anti-inflammatory drugs used to treat many diseases, including rheumatoid arthritis, lupus, asthma, and Crohn’s disease. Other causes of osteoporosis include alcoholism, anorexia nervosa, abnormally low levels of sex hormones, hyperthyroidism, kidney disease, and certain gastrointestinal disorders. Sometimes osteoporosis results from a combination of causes.

Risk Factors for Osteoporosis

Factors that are linked to the development of osteoporosis or contribute to an individual’s likelihood of developing the disease are called risk factors. Many people with osteoporosis have several risk factors for the disease, but others who develop osteoporosis have no identified risk factors. There are some risk factors that you cannot change, and others that you can or may be able to change.

Risk factors you cannot change:

• Sex: Your chances of developing osteoporosis are greater if you are a woman. Women have lower peak bone mass and smaller bones than men. They also lose bone more rapidly than men in middle age because of the dramatic reduction in estrogen levels that occurs with menopause.
• Age: The older you are, the greater your risk of osteoporosis. Bone loss builds up over time, and your bones become weaker as you age.
• Body size: Slender, thin-boned women are at greater risk, as are, surprisingly, taller women.
• Race: Caucasian (white) women are at highest risk, but the disease affects many older Americans of any race or sex.
• Family history: Susceptibility to osteoporosis and fractures appears to be, in part, hereditary. People whose parents have a history of fractures also tend to have reduced bone mass and an increased risk for fractures.

Risk factors you can or may be able to change:

• Sex hormone deficiencies: The most common manifestation of estrogen deficiency in premenopausal women is amenorrhea, the abnormal absence of menstrual periods. Missed or irregular periods can be caused by various factors, including hormonal disorders as well as extreme levels of physical activity combined with restricted calorie intake—for example, in female marathon runners, ballet dancers, and women who spend a great deal of time and energy working out at the gym. Low estrogen levels in women after menopause and low testosterone levels in men also increase the risk of osteoporosis. Lower than normal estrogen levels in men may also play a role. Low testosterone and estrogen levels are often a cause of osteoporosis in men being treated with certain medications for prostate cancer.
• Diet: From childhood into old age, a diet low in calcium and vitamin D can increase your risk of osteoporosis and fractures. Excessive dieting or inadequate caloric intake can also be bad for bone health. People who are very thin and do not have much body fat to cushion falls have an increased risk of fracture.
• Certain medical conditions: In addition to sex hormone problems and eating disorders, other medical conditions—including a variety of genetic, endocrine, gastrointestinal, blood, and rheumatic disorders—are associated with an increased risk for osteoporosis. Anorexia nervosa, for example, is an eating disorder that leads to abnormally low body weight, malnutrition, amenorrhea, and other effects on the body that adversely affect bone health. Late onset of puberty and early menopause reduce lifetime estrogen exposure in women and also increase the risk of osteoporosis.
• Medications: Long-term use of certain medications, including glucocorticoids and some anticonvulsants, leads to bone loss and increased risk of osteoporosis. Other drugs that may lead to bone loss include anticlotting drugs, such as heparin; drugs that suppress the immune system, such as cyclosporine; and drugs used to treat prostate cancer.
• An inactive lifestyle or extended bed rest: Low levels of physical activity and prolonged periods of inactivity can contribute to an increased rate of bone loss. They also leave you in poor physical condition, which can increase your risk of falling and breaking a bone.
• Excessive use of alcohol: Chronic heavy drinking is a significant risk factor for osteoporosis.
• Smoking: Most studies indicate that smoking is a risk factor for osteoporosis and fracture, although the exact reasons for the harmful effects of tobacco use on bone health are unclear.

Diagnosing Osteoporosis

Diagnosing osteoporosis involves several steps, starting with a physical exam and a careful medical history, blood and urine tests, and possibly a bone mineral density assessment. When recording information about your medical history, your doctor will ask questions to find out whether you have risk factors for osteoporosis and fractures. The doctor may ask about any fractures you have had, your lifestyle (including diet, exercise habits, and whether you smoke), current or past health problems and medications that could contribute to low bone mass and increased fracture risk, your family history of osteoporosis and other diseases, and, for women, your menstrual history. The doctor will also do a physical exam that should include checking for loss of height and changes in posture and may include checking your balance and gait (the way you walk).

If you have back pain or have experienced a loss in height or a change in posture, the doctor may request an x ray of your spine to look for spinal fractures or malformations due to osteoporosis. However, x rays cannot necessarily detect osteoporosis. The results of laboratory tests of blood and urine samples can help your doctor identify conditions that may be contributing to bone loss, such as hormonal problems or vitamin D deficiency. If the results of your physical exam, medical history, x rays, or laboratory tests indicate that you may have osteoporosis or that you have significant risk factors for the disease, your doctor may recommend a bone density test.

Mineral is what gives hardness to bones, and the density of mineral in the bones is an important determinant of bone strength. Bone mineral density (BMD) testing can be used to definitively diagnose osteoporosis, detect low bone mass before osteoporosis develops, and help predict your risk of future fractures. In general, the lower your bone density, the higher your risk for fracture. The results of a bone density test will help guide decisions about starting therapy to prevent or treat osteoporosis. BMD testing may also be used to monitor the effectiveness of ongoing therapy.

The most widely recognized test for measuring bone mineral density is a quick, painless, noninvasive technology known as central dual-energy x-ray absorptiometry (DXA). This technique, which uses low levels of x rays, involves passing a scanner over your body while you are lying on a cushioned table. DXA can be used to determine BMD of the entire skeleton and at various sites that are prone to fracture, such as the hip, spine, or wrist. Bone density measurement by DXA at the hip and spine is generally considered the most reliable way to diagnose osteoporosis and predict fracture risk.

The doctor will compare your BMD test results to the average bone density of young, healthy people and to the average bone density of other people of your age, sex, and race. For both women and men, the diagnosis of osteoporosis using DXA measurements of BMD is currently based on a number called a T-score. Your T-score represents the extent to which your bone density differs from the average bone density of young, healthy people. If you are diagnosed with osteoporosis or very low bone density, or if your bone density is below a certain level and you have other risk factors for fractures, the doctor will talk with you about options for treatment or prevention of osteoporosis.

The U.S. Preventive Services Task Force, an independent panel of experts in primary care and prevention, recommends that all women age 65 and older be screened for osteoporosis. The task force also recommends screening for women under the age of 65 who are at high risk for fractures. Men over the age 65 who are at high risk for fractures should talk to their doctor about screening. If you are over 50 and have broken a bone, you may have osteoporosis or be at increased risk for the disease. You should also ask your doctor about osteoporosis if you notice that you have lost height or your posture has become stooped or hunched, or if you experience sudden back pain. You may also want to be evaluated for osteoporosis and fracture risk if you have a chronic disease or eating disorder known to increase the risk of osteoporosis, are taking one or more medications known to cause bone loss, or have multiple risk factors for osteoporosis and osteoporosis-related fractures.

Treating Osteoporosis

The primary goal in treating people with osteoporosis is preventing fractures. A comprehensive treatment program includes a focus on proper nutrition, exercise, and prevention of falls that may result in fractures.

Your doctor may also prescribe one of several medications that have been shown to slow or stop bone loss or build new bone, increase bone density, and reduce fracture risk. If you take medication to prevent or treat osteoporosis, it is still essential that you obtain the recommended amounts of calcium and vitamin D. Exercising and maintaining other aspects of a healthy lifestyle are also important.

For people with osteoporosis resulting from another condition, the best approach is to identify and treat the underlying cause. If you are taking a medication that causes bone loss, your doctor may be able to reduce the dose of that medication or switch you to another medication that is effective but not harmful to your bones. If you have a disease that requires long-term glucocorticoid therapy, such as rheumatoid arthritis or lupus, you can also take certain medications approved for the prevention or treatment of osteoporosis associated with aging or menopause. Staying as active as possible, eating a healthy diet that includes adequate calcium and vitamins, and avoiding smoking and excess alcohol use are also important for people with osteoporosis resulting from other conditions. Children and adolescents with such conditions as juvenile rheumatic diseases and asthma can also be diagnosed with this kind of osteoporosis.

Medical specialists who treat osteoporosis include family physicians, internists, endocrinologists, geriatricians, gynecologists, orthopaedic surgeons, rheumatologists, and physiatrists (doctors specializing in physical medicine and rehabilitation). Physical and occupational therapists and nurses may also participate in the care of people with osteoporosis.

Nutrition

A healthy, balanced diet that includes plenty of fruits and vegetables; enough calories; and adequate calcium, vitamin D, and vitamin K is essential for minimizing bone loss and maintaining overall health. Calcium and vitamin D are especially important for bone health. Calcium is the most important nutrient for preventing osteoporosis and for reaching peak bone mass. For healthy postmenopausal women who are not consuming enough calcium (1,200 mg per day) in their diet, calcium and vitamin D supplements help to preserve bone mass and prevent hip fracture. Calcium is also needed for the heart, muscles, and nerves to work properly and for blood to clot normally. We take in calcium from our diet and lose it from the body mainly through urine, feces, and sweat. The body depends on dietary calcium to build healthy new bone and avoid excessive loss of calcium from bone to meet other needs. The Institute of Medicine of the National Academy of Sciences recommends specific amounts of dietary calcium and vitamin D for various stages of life. Men and women up to age 50 need 1,000 mg of calcium per day, and the recommendation increases to 1,200 mg for women after age 50 and for men after age 70.

Many people in the United States consume much less than the recommended amount of calcium in their diets. Good sources of calcium include low-fat dairy products; dark green leafy vegetables, including broccoli, bok choy, collards, and turnip greens; sardines and salmon with bones; soy beans, tofu, and other soy products; and calcium-fortified foods such as orange juice, cereals, and breads. If you have trouble getting enough calcium in your diet, you may need to take a calcium supplement such as calcium carbonate, calcium phosphate, or calcium citrate. If you are between the ages of 19 and 50, your daily calcium intake should not exceed 2,500 mg because too much calcium can cause problems such as kidney stones. (After age 50, intakes should not exceed 2,000 mg per day.) Calcium coming from food sources provides better protection from kidney stones. Anyone who has had a kidney stone should increase their dietary calcium and decrease the amount from supplements as well as increase fluid intake.

Vitamin D is required for proper absorption of calcium from the intestine. It is made in the skin after exposure to sunlight. Only a few foods naturally contain significant amounts of vitamin D, including fatty fish and fish oils. Foods fortified with vitamin D, such as milk and cereals, are a major dietary source of vitamin D. Although many people obtain enough vitamin D naturally, studies show that vitamin D production decreases in older adults, in people who are housebound, and during the winter—especially in northern latitudes. If you are at risk for vitamin D deficiency, you can take multivitamins or calcium supplements that contain vitamin D to meet the recommended daily intake of 600 International Units (IU) for men and women up to the age of 70 and 800 IU for people over 70. Doses of more than 2,000 IU per day are not advised unless under the supervision of a doctor. Larger doses can be given initially to people who are deficient as a way to replenish stores of vitamin D.

Lifestyle

In addition to a healthy diet, a healthy lifestyle is important for optimizing bone health. You should avoid smoking and, if you drink alcohol, do so in moderation (no more than one drink per day is a good general guideline). It is also important to recognize that some prescription medications can cause bone loss or increase your risk of falling and breaking a bone. Talk to your doctor if you have concerns about any medications you are taking.

Exercise

Exercise is an important part of an osteoporosis treatment program. Physical activity is needed to build and maintain bone throughout adulthood, and complete bed rest leads to serious bone loss. The evidence suggests that the most beneficial physical activities for bone health include strength training or resistance training. Exercise can help maintain or even modestly increase bone density in adulthood and, together with adequate calcium and vitamin D intake, can help minimize age-related bone loss in older people. Exercise of various sorts has other important benefits for people with osteoporosis. It can reduce your risk of falling by increasing muscle mass and strength and improving coordination and balance. In older people, exercise also improves function and delays loss of independence.

Although exercise is beneficial for people with osteoporosis, it should not put any sudden or excessive strain on your bones. If you have osteoporosis, you should avoid high impact exercise. To help ensure against fractures, a physical therapist or rehabilitation medicine specialist can recommend specific exercises to strengthen and support your back, teach you safe ways of moving and carrying out daily activities, and recommend an exercise program that is tailored to your circumstances. Other trained exercise specialists, such as exercise physiologists, may also be able to help you develop a safe and effective exercise program.

Fall Prevention

Fall prevention is a critical concern for men and women with osteoporosis. Falls increase your likelihood of fracturing a bone in the hip, wrist, spine, or other part of the skeleton. Fractures can affect your quality of life and lead to loss of independence and even premature death. A host of factors can contribute to your risk of falling.

Falls can be caused by impaired vision or balance, loss of muscle mass, and chronic or short-term illnesses that impair your mental or physical functioning. They can also be caused by the effects of certain medications, including sedatives or tranquilizers, sleeping pills, antidepressants, anticonvulsants, muscle relaxants, some heart medicines, blood pressure pills, and diuretics. Use of four or more prescription medications has also been shown to increase the risk for falling. Drinking alcoholic beverages is another risk factor. If you have osteoporosis, it is important to be aware of any physical changes you may be experiencing that affect your balance or gait and to discuss these changes with your doctor or other health care provider. It is also important to have regular checkups and tell your doctor if you have had problems with falling.

The force or impact of a fall (how hard you land) plays a major role in determining whether you will break a bone. Catching yourself so that you land on your hands or grabbing onto an object as you fall can prevent a hip fracture. You may break your wrist or arm instead, but the consequences are not as serious as if you break your hip. Studies have shown that wearing a specially designed garment that contains hip padding may reduce hip fractures resulting from falls in frail, elderly people living in nursing homes or residential care facilities, but use of the garments by residents is often low.

Falls can also be caused by factors in your environment that create unsafe conditions. Some tips to help eliminate the environmental factors that lead to falls include:

Outdoors and away from home:

• Use a cane or walker for added stability.
• Wear shoes that give good support and have thin nonslip soles. Avoid wearing slippers and athletic shoes with deep treads.
• Walk on grass when sidewalks are slippery; in winter, sprinkle salt or kitty litter on slippery sidewalks.
• Be careful on highly polished floors that are slick and dangerous, especially when wet, and walk on plastic or carpet runners when possible.
• Stop at curbs and check their height before stepping up or down.

Indoors:

• Keep rooms free of clutter, especially on floors.
• Keep floor surfaces smooth but not slippery.
• Wear shoes that give good support and have thin nonslip soles. Avoid wearing slippers and athletic shoes with deep treads.
• Be sure carpets and area rugs have skid-proof backing or are tacked to the floor. Use double-stick tape to keep rugs from slipping.
• Be sure stairwells are well lit and that stairs have handrails.
• Install grab bars on bathroom walls near tub, shower, and toilet.
• Use a rubber bathmat or slip-proof seat in the shower or tub.
• Improve the lighting in your home. Use a nightlight or flashlight if you get up at night.
• Use stepladders that are stable and have a handrail.
• Install ceiling fixtures or lamps that can be turned on by a switch near the room’s entrance.
• If you live alone (or spend large amounts of time alone), consider purchasing a cordless phone; you won’t have to rush to answer the phone when it rings and you can call for help if you do fall.
• Consider having a personal emergency-response system; you can use it to call for help if you fall.

Medications

The U.S. Food and Drug Administration (FDA) has approved several medications for prevention or treatment of osteoporosis, based on their ability to reduce fractures.¹

¹All medicines can have side effects. Some medicines and side effects are mentioned in this publication. Some side effects may be more severe than others. You should review the package insert that comes with your medicine and ask your health care provider or pharmacist if you have any questions about the possible side effects.

Bisphosphonates: Several bisphosphonates are approved for the prevention or treatment of osteoporosis. These medications reduce the activity of cells that cause bone loss.

Parathyroid hormone: A form of human parathyroid hormone (PTH) is approved for postmenopausal women and men with osteoporosis who are at high risk for having a fracture. Use of the drug for more than 2 years is not recommended.

RANK ligand (RANKL) inhibitor: A RANK ligand (RANKL) inhibitor is approved for postmenopausal women with osteoporosis and men who are at high risk for fracture.

Estrogen agonists/antagonists: An estrogen agonist/antagonist (also called a selective estrogen receptor modulator or SERM) is approved for the prevention and treatment of osteoporosis in postmenopausal women. SERMs are not estrogens, but they have estrogen-like effects on some tissues and estrogen-blocking effects on other tissues.

Calcitonin: Calcitonin is approved for the treatment of osteoporosis in women who are at least 5 years beyond menopause. Calcitonin is a hormone involved in calcium regulation and bone metabolism.

Estrogen and hormone therapy: Estrogen and combined estrogen and progestin (hormone therapy) are approved for the prevention of postmenopausal osteoporosis as well as the treatment of moderate to severe hot flashes and vaginal dryness that may accompany menopause. Estrogen without an added progestin is recommended only for women who have had a hysterectomy (surgery to remove the uterus), because estrogen increases the risk of developing cancer of the uterine lining and progestin reduces that risk.

The Food and Drug Administration has recommended that women use hormone therapy at the lowest dose and for the shortest time, and carefully consider and discuss with their doctor other approved osteoporosis treatments.

Alternative Therapies

Isoflavones are naturally occurring compounds found in soybeans. Because they are structurally similar to estrogen, researchers have thought that they may hold promise as an alternative to estrogen therapy to protect postmenopausal women from osteoporosis. Several studies have explored the effects of soy isoflavones on bone health, but results have been mixed, ranging from a modest impact to no effect. Most of these studies had various limitations, including their short duration and small sample size, making it difficult to fully evaluate the impact of these compounds on bone health. Moreover, reports from NIH-supported clinical trials have failed to demonstrate a bone-sparing effect of soy isoflavones.

Preventing Osteoporosis

Preventing osteoporosis is a lifelong endeavor. To reach optimal peak bone mass and minimize loss of bone as you get older, there are several factors you should consider. Addressing all of these factors is the best way to optimize bone health throughout life.

An inadequate supply of calcium over a lifetime is thought to play a significant role in the development of osteoporosis.

Calcium

An inadequate supply of calcium over a lifetime is thought to play a significant role in the development of osteoporosis. Many published studies show that low calcium intakes are associated with low bone mass, rapid bone loss, and high fracture rates. National surveys suggest that the average calcium intake of individuals is far below the levels recommended for optimal bone health. Individuals who consume adequate amounts of calcium and vitamin D throughout life are more likely to achieve optimal skeletal mass early in life and are less likely to lose bone later in life.

Calcium needs change during your lifetime. The body’s demand for calcium is greater during childhood and adolescence, when the skeleton is growing rapidly, and in women during pregnancy and breastfeeding. Postmenopausal women and older men also need to consume more calcium. Increased calcium requirements in older people may be related to vitamin D deficiencies that reduce intestinal absorption of calcium. Also, as you age, your body becomes less efficient at absorbing calcium and other nutrients. Older adults are also more likely to have chronic medical problems and to use medications that may impair calcium absorption. Calcium and vitamin D supplements may help slow bone loss and prevent hip fracture. Information on how to ensure adequate calcium intake is provided in “Treating Osteoporosis.” Further details are also available from several of the organizations listed at the end of this publication.

Adolescence is the most critical period for building bone mass that helps protect against osteoporosis later in life. Yet studies show that among children age 9 to 19 in the United States, few meet the recommended levels. Therefore, it is especially important for parents, other caregivers, and pediatricians to talk to children and young teens about developing bone-healthy habits, including eating calcium-rich foods and getting enough exercise.

More information on this subject is available in the NIH publication Kids and Their Bones.

Vitamin D

Vitamin D plays an important role in calcium absorption and bone health. It is made in the skin after exposure to sunlight and can also be obtained through the diet, as described in the section of this publication on treating osteoporosis. Although many people are able to obtain enough vitamin D naturally, vitamin D production decreases in the elderly, in people who are housebound or do not get enough sun, and in some people with chronic neurological or gastrointestinal diseases. These individuals and others at risk for vitamin D deficiency may require vitamin D supplementation. The recommended daily intake of vitamin D is 400 International Units (IU) for infants, 600 IU for children and adults up to age 70, and 800 IU for people over 70.

Overall Nutrition

A healthy, balanced diet that includes lots of fruits and vegetables and enough calories is also important for lifelong bone health.

Exercise

Like muscle, bone is living tissue that responds to exercise by becoming stronger. There is good evidence that physical activity early in life contributes to higher peak bone mass. (However, remember that excessive exercise can be bad for bone health.) The best exercise for building and maintaining bone mass is weight-bearing exercise: exercise that you do on your feet and that forces you to work against gravity. Weight-bearing exercises include jogging, aerobics, hiking, walking, stair climbing, gardening, weight training, tennis, and dancing. High-impact exercises may provide the most benefit. Bicycling and swimming are not weight-bearing exercises, but they have other health benefits. Exercise machines that provide some degree of weight-bearing exercise include treadmills, stair-climbing machines, ski machines, and exercise bicycles.

Strength training to build and maintain muscle mass and exercises that help with coordination and balance are also important. Later in life, the benefits of exercise for building and maintaining bone mass are not nearly as great, but staying active and doing weight-bearing exercise is still important. A properly designed exercise program that builds muscles and improves balance and coordination provides other benefits for older people, including helping to prevent falls and maintaining overall health and independence. Experts recommend 30 minutes or more of moderate physical activity on most (preferably all) days of the week, including a mix of weight-bearing exercises, strength training (two or three times a week), and balance training.

Smoking

Smoking is bad for your bones and for your heart and lungs. Women who smoke have lower levels of estrogen compared to nonsmokers and frequently go through menopause earlier.

Alcohol

People who drink heavily are more prone to bone loss and fractures because of poor nutrition and harmful effects on calcium balance and hormonal factors. Drinking too much also increases the risk of falling, which is likely to increase fracture risk.

Medications That Cause Bone Loss

The long-term use of glucocorticoids can lead to a loss of bone density and fractures. Other forms of drug therapy that can cause bone loss include long-term treatment with certain antiseizure drugs and barbiturates, some drugs used to treat endometriosis, excessive use of aluminum-containing antacids, certain cancer treatments, and excessive thyroid hormone. It is important to discuss the use of these drugs with your doctor, and not to stop or alter your medication dose on your own. See “Causes of Osteoporosis” for more information.

Research Highlights

The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) leads the Federal research effort on osteoporosis. Scientists at universities, medical centers, and other research institutions across the United States who are funded by the NIAMS and other National Institutes of Health (NIH) components are pursuing a wide range of basic and clinical studies on the disease.

Significant advances in preventing and treating osteoporosis continue to be made. Such advances are the direct result of research focused on:

• determining the causes and consequences of bone loss at the cellular and tissue levels
• assessing risk factors
• developing new strategies to maintain and even enhance bone density and reduce fracture risk
• exploring the roles of such factors as genetics, hormones, calcium, vitamin D, drugs, and exercise on bone mass.

Some key areas of osteoporosis research supported by the NIAMS and its partners at the NIH are described below.

Genetic Studies

Researchers are continuing to define genetic differences that underlie variation in bone formation, maintenance, and turnover. Applying the findings of genome-wide association studies to identify new molecular pathways related to bone health and disease may lead to new ways to prevent bone loss and fractures.

Bone Cell Biology

Scientists are exploring the biochemical pathways and cellular interactions that underlie the physiology of healthy, damaged, and diseased musculoskeletal tissues. Study of the cells that control bone remodeling continues to yield insights on the underlying causes of osteoporosis and points to possible new therapeutic targets.

Over the past several years, researchers have made considerable progress in understanding connections between bone physiology and the broader network of biologic processes involving many different organs and tissues. Scientists are working to explain the connection between the skeleton and the nervous system; other tissues such as fat, muscle, cartilage; the immune system; digestion and nutrition (including the role of the microbiome); and energy metabolism.

Study of Osteoporotic Fractures

The Study of Osteoporotic Fractures (SOF), which is supported by the NIAMS and the National Institute on Aging (NIA), is a multicenter study of 10,000 postmenopausal Caucasian women that has yielded comprehensive data about multiple risk factors for osteoporosis-related fractures. This study, which began in 1986, has provided the foundation for developing ways to identify people at greatest risk for osteoporosis and fractures decades in advance, and thus has greatly aided disease prevention efforts.

Osteoporosis in Men

Osteoporosis in men has undergone major scrutiny in a multicenter study funded by the NIAMS in partnership with the NIA and the National Cancer Institute. The Osteoporosis in Men study (MrOS) enrolled 6,000 men age 65 years and older, and has identified significant risk factors for osteoporosis, falls, and fractures in men.

Evaluating and Assessing Bone Quality

Scientists are exploring architectural and material factors that influence bone quality in hopes of gaining a better understanding of how properties of bone other than its mass or density affect bone strength. They are also developing new methods to assess bone quality and bone strength and predict fracture risk based on technologies such as ultrasound, computed tomography and magnetic resonance imaging.

Treatments for Osteoporosis

Researchers are examining the molecular and cellular mechanisms by which currently used osteoporosis drugs work, in the hope of advancing knowledge about their application to bone. In other studies, scientists are investigating novel approaches for preventing fractures associated with osteoporosis and related conditions.

Investigators are assessing the potential of combining therapeutic agents to achieve additive or synergistic treatment benefits in people with osteoporosis. As well, studies are comparing the effectiveness of different therapeutic approaches.

Prevention Studies

Researchers continue to explore the impact of nutritional status on bone health and fracture risk. Scientists are examining the impact of physical activity levels on bone health and are developing and testing strategies to promote bone health through exercise and physical rehabilitation programs.

Researchers are also exploring effects of environmental factors, such as smoking and environmental toxins, on skeletal health.

Hope for the Future

With ongoing research, experts hope that osteoporosis will come to be considered a curable disease. Research has enhanced our knowledge about how to maintain a healthy skeleton throughout life and has led to progress in understanding the causes, prevention, diagnosis, and treatment of osteoporosis. Every research advance brings us closer to eliminating the pain and suffering caused by this disease.

For More Information

NIH Osteoporosis and Related Bone Diseases
National Resource Center

National Institutes of Health
2 AMS Circle
Bethesda, MD 20892–3676
Phone: 202–223–0344
Toll free: 800–624–BONE (2663)
TTY: 202–466–4315
Fax: 202–293–2356
Email: [email protected]
Website: www.bones.nih.gov

Other Resources

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
National Institutes of Health

1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484
Toll free: 877-22-NIAMS (877-226-4267)
TTY: 301-565-2966
Fax: 301-718-6366
Email: [email protected]
Website: https://www.niams.nih.gov

If you need more information about available resources in your language or another language, please visit our website or contact the NIAMS Information Clearinghouse at [email protected].

National Institute on Aging

Website: http://www.nia.nih.gov/

American Academy of Orthopaedic Surgeons

Website: http://www.aaos.org (con información en español)

American Geriatrics Society

Website: http://www.americangeriatrics.org

American Society for Bone and Mineral Research

Website: http://www.asbmr.org

National Osteoporosis Foundation

Website: http://www.nof.org

Acknowledgments

The NIAMS gratefully acknowledges the assistance of the following individuals in the preparation and review of the original versions of this publication: Joan McGowan, Ph.D., and William Sharrock, Ph.D., NIAMS/NIH; Sundeep Khosla, M.D., Mayo Clinic College of Medicine, Rochester, MN; Barbara Lukert, M.D., University of Kansas, Kansas City, KS; and Eric Orwoll, M.D., Oregon Health and Science University, Portland, OR.

The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH), is to support research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. The NIAMS Information Clearinghouse is a public service sponsored by the Institute that provides health information and information sources. Additional information can be found on the NIAMS website at www.niams.nih.gov.

For Your Information

This publication contains information about medications used to treat the health condition discussed here. When this publication was developed, we included the most up-to-date (accurate) information available. Occasionally, new information on medication is released.

For updates and for any questions about any medications you are taking, please contact

U.S. Food and Drug Administration

Toll free: 888-INFO-FDA (888-463-6332)
Website: http://www.fda.gov

For additional information on specific medications, visit Drugs@FDA at http://www.accessdata.fda.gov/scripts/cder/drugsatfda. Drugs@FDA is a searchable catalog of FDA-approved drug products.

For updates and questions about statistics, please contact

Centers for Disease Control and Prevention, National Center for Health Statistics

Website: http://www.cdc.gov/nchs

This publication is not copyrighted. You can make copies of it and give out as many as you want.

Additional copies of this publication are available from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIAMS/National Institutes of Health, 1 AMS Circle, Bethesda, MD 20892-3675, and on the NIAMS website at www.niams.nih.gov.

NIH Publication No. 16-5158