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In This Report

•	Highlights
•	Introduction
•	Causes
•	Symptoms
•	Fractures
•	Risk Factors
•	Diagnosis
•	Lifestyle Changes
•	Medications
•	Treatment
•	Resources
•	References

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Osteoporosis

Highlights

Drug Approvals

• Ibandronate (Boniva) approved as first once-a-month pill for both treatment and prevention of osteoporosis.
• Ibandronate (Boniva) injection approved as the first intravenous bisphosphonate for treatment of osteoporosis. The injection is given once every 3 months in a doctor’s office.
• Risedronate (Actonel) approved to treat osteoporosis in men.

Investigational Drugs

A once-yearly bisphosphonate drug, administered in a 15-minute intravenous infusion, may be the next new osteoporosis treatment. Encouraging Phase III results for Reclast were presented at the 2006 meeting of the American Society for Bone and Mineral Research.

Osteonecrosis of the Jaw

Osteonecrosis (bone decay) in the jaw is a rare side effect of bisphosphonate drugs. It has mostly occurred in patients who received intravenous bisphosphonates, but there have been a few cases in people who took oral bisphosphonates. Talk to your doctor if you have signs of jaw or gum discomfort.

Calcium Supplements for Osteoporosis Prevention

Calcium and vitamin supplements do not have major benefits for osteoporosis prevention, according to a landmark Women’s Health Initiative clinical trial. The 2006 study, published in the New England Journal of Medicine, found that the supplements provide only modest protection for hip fractures and bone loss, and may increase the risk of kidney stones. Doctors have different opinions about whether women should continue to take supplements.

Bone Density Screening

• Bone density screening can help prevent hip fractures, according to a 2005 study in the Annals of Internal Medicine. However, researchers were unsure if exercise behavior and other lifestyle factors had a greater effect on fractures than screening.
• Women who need screening the most are least likely to get it, suggests a 2006 study in the Journal of the American Geriatrics Society. The study found that less than 10% of women older than age 75 received bone density screenings, even though they are the group most at risk for hip fractures.

Introduction

Osteoporosis is a disease of the skeleton in which bones become brittle and prone to fracture. In other words, the bone loses density. Osteoporosis is diagnosed when bone density has decreased to the point where fractures occur with mild stress.

The skeleton consists of groups of bones which protect and move the body.

Until a healthy person is around age 40, the process of breaking down and building up bone by cells called osteoclasts and osteoblasts is a nearly perfectly coupled system, with one phase stimulating the other. As a person ages, or in the presence of certain conditions, this system breaks down and the two processes become out of sync. The reasons why this occurs during aging are not clear. Some individuals have a very high turnover rate of bone, some have a very gradual turnover, but the breakdown of bone eventually overtakes the build-up.

Primary Osteoporosis

There are two primary kinds of osteoporosis: type I and type II:

• Type I. Type I, or high turnover, osteoporosis occurs in 5 - 20% of women, most often between the ages of 50 and 75. This is because of the sudden postmenopausal decrease in estrogen levels, which results in a rapid depletion of calcium from the skeleton. This is associated with fractures that occur when the vertebrae compress together, causing a collapse of the spine. It is also associated with fractures of the hip, wrist, or forearm caused by falls or minor accidents. Type 1 accounts for the significantly greater risk for osteoporosis in women than in men.
• Type II. Type II, or low turnover, osteoporosis (also known as age-related or senile osteoporosis) results when the process of resorption and formation of bone are no longer coordinated, and bone breakdown overcomes bone building. (This occurs with age in everyone to some degree.) Type II osteoporosis affects both men and women and is primarily associated with leg and spinal fractures. Older women can have both type I and type II osteoporosis.

Click the icon to see an image of a compression fracture.

The determining factor for the actual existence of osteoporosis, whether type I or type II, is the amount of calcium left in the skeleton and whether it places a person at risk for fracture. Someone who has exceptionally dense bones to begin with will probably never lose enough calcium to reach the point where osteoporosis occurs, whereas a person who has low bone density could easily develop osteoporosis despite losing only a relatively small amount of calcium.

Secondary Osteoporosis

Secondary osteoporosis is caused by other conditions, such as hormonal imbalances, diseases, or medications (such as corticosteroids or anti-seizure drugs). Details on the many other causes of secondary disease are included throughout this report.

Click the icon to see an image of osteoporosis.

Causes

Because the patterns of reforming and resorbing bone often vary from patient to patient, experts believe several different factors account for this problem. Important chemicals (such as estrogen, parathyroid hormone, and vitamin D) and blood factors that affect cell growth are involved with this process. Changes in levels of any of these factors could play a role in the development of osteoporosis.

The Role of Sex Hormones in Bone Breakdown

Although ordinarily associated with women, sex hormones play a role in osteoporosis in both genders, most likely by controlling the birth and duration of life of both osteoclasts (bone breakers) and osteoblasts (bone builders).

Women and Estrogen. Experts are still puzzled by the rapid decline in bone density after menopause, when a woman’s ovaries stop producing estrogen. Estrogen comes in several forms:

The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. The ovaries produce the eggs that travel through the fallopian tubes. Once the egg has left the ovary it can be fertilized and implant itself in the lining of the uterus. The main function of the uterus is to nourish the developing fetus prior to birth.

• The most potent form of estrogen is estradiol. Estradiol deficiency appears to be a very strong factor in the development of osteoporosis.
• The other important but less powerful estrogens are estrone and estriol.

The ovaries produce most of the estrogen in the body, but it can also be formed in other tissues, such as body fat, skin, and muscle. After menopause, some amounts of estrogen continue to be manufactured in the peripheral body fat. Even though the ovaries have stopped producing estrogens directly, they continue to be a source of the male hormone testosterone, which converts into estradiol.

Estrogen may have an impact on bone density in various ways:

• Estrogen’s most important effect on osteoporosis appears to be prevention of bone breakdown (resorption). Some research suggests that estrogen may control the life span of osteoclasts, the cells responsible for bone breakdown.
• One study reported that part of estrogen’s beneficial actions may involve maintaining normal levels of vitamin D, an important nutrient in bone protection.

Men and Androgens and Estrogen. In men, the most important androgen (male hormone) is testosterone, which is produced in the testes. Other androgens are produced in the adrenal glands. Androgens are converted to estrogen in various parts of a man’s body, including bone.

Click the icon to see an image of the adrenal glands.

Studies have suggested that the loss of estrogen as well as testosterone may contribute to bone loss in elderly men. In one study, elderly men were first given a drug that blocked their normal hormones and then were given estrogen and testosterone patches. When the estrogen patch was removed, the bone breakdown process accelerated. When both patches were removed, the number of the bone-building cells (the osteoblasts) decreased. In other words, both hormones appeared to be integral to bone function in men.

Vitamin D and Parathyroid Hormone Imbalances

Low levels of vitamin D and high levels of parathyroid hormone (PTH) are associated with hip fracture in women after menopause:

• Vitamin D is a vitamin with hormone-like properties. It is essential for the absorption of calcium into the bone and for normal bone growth. Lower levels result in impaired calcium absorption, which in turn causes an increase in PTH.
• Parathyroid hormone (PTH) is produced by the parathyroid glands. These are four small glands located on the surface of the thyroid gland. They are the most important regulators of calcium levels in the blood. When calcium levels are low, the glands secrete more PTH, which then increases blood calcium levels. High persistent levels of PTH stimulate bone resorption (bone loss).

Click the icon to see an image of the benefits of vitamin D.

Click the icon to see an image of the sources of vitamin D.

Click the icon to see an image of the parathyroid glands.

Genetic Factors

Several studies on family members, including twins, have strongly suggested that genetic factors help determine bone density. Some examples include the following:

• Of particular interest are genetic factors that affect vitamin D, a critical nutrient for calcium absorption in the body.
• Many studies are looking at abnormalities in genes that may cause deficiencies in estrogen receptors, molecules that help estrogen work on cells. Estrogen is important in maintaining bone density in both men and women.

Causes of Secondary Osteoporosis

Corticosteroids. More than 30 million Americans have disorders that are commonly treated using corticosteroids (also called glucocorticoids or steroids). Oral corticosteroids are known to reduce bone mass in both men and women. Studies report a higher risk for bone loss in adults who take inhaled steroids regularly. The risk is higher with increasing doses, but is still lower than with oral steroids. (Children on inhaled steroids may have temporary impaired growth, but they do not appear to be at risk for bone loss.)

Other Medications. Anti-epileptic (also called anti-seizure) drugs increase the risk for bone loss (as does epilepsy itself). Other drugs that increase the risk for bone loss include heparin, progestin without estrogen (such as Depo-Provera or other progestin-based contraceptives), and hormonal drugs that suppress estrogen (such as gonadotropin-releasing hormone agonists). Diuretics (used to treat high blood pressure) have different effects on osteoporosis, depending on the type. Loop diuretics, which block sodium, have been associated with bone loss. Thiazide diuretics, on the other hand, confer protection against fracture during the time they are used.

Predisposing Medical Conditions. Osteoporosis can be secondary to several other conditions, including alcoholism, diabetes, hyperthyroidism, epilepsy, chronic liver or kidney disease, celiac disease, scurvy, rheumatoid arthritis, leukemia, cirrhosis, gastrointestinal diseases, vitamin D deficiency, hypogonadism (impaired development of reproductive organs), lymphoma, hyperparathyroidism, and rare genetic disorders such as Marfan’s and Ehlers-Danlos syndrome.

Symptoms

Many people confuse osteoporosis with arthritis and believe they can wait for symptoms such as swelling and joint pain to occur before seeing a doctor. However, the mechanisms that cause arthritis are entirely different from those in osteoporosis. Osteoporosis usually becomes quite advanced before symptoms appear.

All too often, osteoporosis becomes apparent in dramatic fashion: a fracture of a vertebra (backbone), hip, forearm, or any bony site if sufficient bone mass is lost. These fractures frequently occur after apparently minor trauma, such as bending over, lifting, jumping, or falling from the standing position.

Pain, disfigurement, and debilitation are common in the latter stages of the disease. Early spinal compression fractures may go undetected for a long time, but after a large percentage of calcium has been lost, the vertebrae in the spine start to collapse, gradually causing a stooped posture called kyphosis, or a "dowager’s hump." Although this is usually painless, patients may lose as much as 6 inches in height.

Click the icon to see an image of osteoporosis.

Fractures

Bone density loss from osteoporosis is a major cause of disability and death in the elderly, mostly due to subsequent fractures. The lifetime risk of spinal fracture in women is about one in three, and that for hip fracture is one in six. Women at highest risk for fractures are those with low bone density plus a history of fractures, particularly nonviolent fractures.

Click the icon to see an animation about osteoporosis.

Each year, there are an estimated 500,000 spinal fractures, 300,000 hip fractures, 200,000 broken wrists and 300,000 fractures of other bones. About 80% of these fractures occur after relatively minor falls or accidents.

Between 25 - 60% of women older than age 60 develop spinal compression fractures. Studies on men with osteoporosis report that they have a 6% risk for hip fracture and between 16 - 25% risk for any fractures related to osteoporosis.

Click the icon to see an image of a compression fracture.

Click the icon to see an image of a hip fracture.

Unfortunately, studies continue to report inadequate treatment after a fracture. In a major 2003 study, for example, only 8.4% of women who had sustained fractures were tested for osteoporosis. Worse, less than half of these women received any treatment for osteoporosis. Overall, in the study less than 4% of men and half of women who had sustained fractures were evaluated and treated according to recommended guidelines. The older a woman was, the less likely she was to have adequate treatment.

Risk Factors for Fracture and Falling. The risk for fracture itself in people with low bone density is compounded by certain features. Having multiple risk factors for osteoporosis itself poses a higher risk for fractures. However, not all older women with osteoporosis develop fractures. There is some evidence that the body partially compensates after menopause by increasing bone strength, which can help offset the risk for fracture.

Falling, of course, is the primary risk factor for fracture. So, additional risk factors for fracture are those that increase the risk for falling. They include:

• Having chronic medical problems (emphysema, heart disease, stroke, arthritis, and depression), with the risk increasing with multiple health problems. Such problems may account for 30% of falls in older women.
• Taking multiple medications (especially tranquilizers and antidepressants).
• Poor physical function, importantly slow gait and reduced muscle strength. Inactivity that results in weak thigh muscles and poor balance particularly puts any older person at risk for fracture and particularly those with low bone density.
• Poor concentration or mental impairment.
• Impaired vision.
• Hazardous environment (such as the presence of throw rugs in the house).

Mortality Rates After Fracture

Between 25 - 36% of women who experience a hip fracture die within a year afterward, and about a quarter of the patients require nursing home treatment. The mortality rates after major fractures may be even higher in older men than in older women. Mortality rates after hip fractures declined from the 1960s through the early 1980s, but they have since leveled off. Whether or not medical advances can improve mortality rates in the future, prevention of osteoporosis is extremely important.

Risk Factors

Gender. An estimated 10 million adults in the United States have osteoporosis and another 34 million have low bone mass that places them at risk for developing osteoporosis. A 2004 report from the Surgeon General's office estimates that by 2020, half of all Americans over age 50 could be at risk for this condition. Eighty percent of people with osteoporosis are women. Men start with higher bone density and lose calcium at a slower rate than women, which is why their risk is far lower. Nevertheless, after age 50, bone loss increases and, according to recent studies, more rapidly than previously thought.

Ethnicity. Although adults from all ethnic groups are susceptible to developing osteoporosis, Caucasian and Asian women and men face a comparatively greater risk. Approximately 20% of non-Hispanic white and Asian women older than age 50 have osteoporosis, and over 50% are at risk due to low bone mass. Osteoporosis affects 10% of Hispanic women (49% at risk) and 5% of non-Hispanic black women (35% at risk). Body type can also be a factor.Osteoporosis is more common in women who have a small, thin body frame and bone structure.

Specific Risk Factors for Estrogen Deficiency and Low Bone Density in Women

Events associated with estrogen deficiencies are the primary risk factors for osteoporosis in women.

Natural and Surgical Causes of Estrogen Deficiency.

• Menopause. Within 5 years after menopause, the risk for fracture increases dramatically. Fractures occurring during this period are more likely to occur in the wrist or spine than the hip, but their occurrence is a strong predictor of later severe osteoporosis and hip fracture.
• Surgical removal of ovaries.
• Missing periods for 3 months or longer.
• Never giving birth.
• Paradoxically, pregnancy and nursing do not increase the risk for osteoporosis even though during those times calcium is diverted from the mother to the baby. A factor believed to be associated with reduced bone density is elevated at a constant level during nursing, but as the baby is weaned, levels of the factor decline and bone formation is restored.

Female Athlete Triad. In athletes, excessive exercise plays a major role in many cases of anorexia (and, to a lesser degree, bulimia), which in turn increases the risk for low estrogen levels and bone loss. The term "female athlete triad" in fact, is now a common and serious disorder facing young female athletes and dancers and describes the combined presence of the following problems:

• Osteoporosis
• Amenorrhea (absence or irregular menstruation)
• Eating disorders

Specific Risk Factors for Bone Density Loss in Men

Some specific risk factors in men include:

• Hormonal deficiencies, including both testosterone and estrogen, which occur in older men (although much more slowly than in women). Estrogen deficiencies may also play a major role in osteoporosis in older men. It is unknown yet what normal estrogen levels are in men.
• Medical conditions that can reduce testosterone levels, such as prostate cancer treatments, testicular surgery, and mumps.
• Hypogonadism, which is a severe deficiency in the primary hormone that signals the process leading to the release of testosterone and other important reproductive hormones.

Of concern, are studies suggesting that men who have osteoporosis and suffer hip fractures are far less likely to be tested and treated for low bone density than are women. In one study, only 27% of men were treated for osteoporosis compared to 71% of women.

Risk Factors for Bone Density Loss in Both Men and Women

Dietary Factors. Diet plays an important role in preventing and speeding up bone loss in men and women. Calcium and vitamin D deficiencies, of course, are important factors in the risk for osteoporosis. Other dietary factors may also be harmful or protective for certain people.

Calcium requires adequate vitamin D in order to be absorbed by the body. In the United States, many food sources of calcium such as milk are fortified with vitamin D.

Click the icon to see an image of the sources of calcium.

Lack of Exercise. Lack of exercise can put thinner people at risk for osteoporosis.

Being Underweight. Being underweight is a risk factor for osteoporosis in men as well as women. (Shortness, thinness, and narrow hips all increase the risk for fracture in people with low bone density.)

Lack of Sunlight. The photochemical effect of sunlight on the skin is a primary source for vitamin D. Bone formation peaks in the summer and bone breakdown increases in the winter. People who avoid sun exposure to prevent skin cancer may be at risk for vitamin D deficiency, particularly it they are elderly.

Click the icon to see an image of the sources of vitamin D.

Smoking. Women who smoke, particularly after menopause, have a significantly greater chance of spine and hip fractures than those who don’t smoke. Men who smoke also have lower bone density.

Diabetes. Diabetes changes bone quality and density and increases the risk for osteoporosis, but the effects differ depending on type:

• Type 1 diabetes is associated with a slightly reduced bone density, putting patients at risk for osteoporosis and possibly fracture.
• Type 2 diabetes, on the other hand, is associated with an increased bone density. In such cases, the bone quality itself may be impaired, since people with type 2 diabetes are still at higher risk for fractures.

Older patients with any diabetes type are at high risk for falling, which compounds the risk for fracture.

Risk Factors in Children and Adolescents

The maximum density that bones achieved during the growing years is a major factor in whether a person goes on to develop osteoporosis. Persons, usually women, who never develop peak bone mass in early life are at high risk for osteoporosis later on. Children at risk for low peak bone mass include children who are:

• Born prematurely
• Have anorexia nervosa (more common in girls)
• Young, highly competitive athletes
• Take oral corticosteroid drugs (inhaled steroids, which are common in asthma treatments, appear to pose a very low risk or none at all)
• Have certain medical conditions (cystic fibrosis, epilepsy, inflammatory bowel disease, and celiac disease)
• Have delayed puberty

Although to a large extent genetics predict bone health, exercise and good nutrition during the first three decades of life (when peak bone mass is reached) are still excellent safeguards against osteoporosis (and countless other health problems).

Other Factors Associated with Osteoporosis

Depression. One study found an association between major depression and low bone mineral density in women. More than a third of premenopausal women who suffered from major depression had low bone density comparable to that of postmenopausal women. One explanation for this association is that depressed women have higher levels of the stress hormone cortisol, which may contribute to bone density loss.

Premature Gray Hair. One study reported that men and women whose hair turns gray in their 20s or was half gray by age 40 have an incidence of thin bones that is four times higher than those who go gray later. Smoking, which also contributes to thin bones, has also been associated with premature gray hair.

Diagnosis

About 20 - 30% of Caucasian women in the U.S. can expect to be affected by osteoporosis, including having a spinal fracture, after age 60. Hispanic, Asian, and Native American women have an even higher risk. Nearly all of them are unaware of the condition and so fail to seek a diagnosis. Even worse, studies continue to report inadequate evaluation for osteoporosis even after a fracture.

Candidates for Bone Density Screening or Testing

Evidence suggests that screening for osteoporosis can help prevent fractures. Expert groups now recommend bone density screening for the following people:

• All women over age 65.
• Any postmenopausal women under 65 years with risk factors for osteoporosis (being thin, being a smoker, having a family history of osteoporosis, corticosteroids use, or any serious high-risk condition, such as hyperthyroidism or early menopause).
• Any older men or women who suffer a fracture. (Unfortunately, studies suggest that only a minority of these patients are evaluated and treated for osteoporosis. Men are especially less likely to be tested.)

Whether perimenopausal women should be screened is unclear. (Perimenopause is the period that extends a few years before and after menopause, usually ages 50 - 59.) Some experts believe that women as young as 21 who have strong risk factors for osteoporosis (such as anorexia or absence of menstruation due to over-exercising) should consider being tested. It is also important that older women continue to get bone density tests. A 2006 study found that only 10% of women over age 75 receive bone density screenings, even though they are the age group most likely to have hip fractures.

Techniques Used for Measuring Bone Density

Bone Densitometry. The standard technique for determining bone density is a form of bone densitometry called dual-energy x-ray absorptiometry (DEXA). DEXA is simple and painless and takes 2 - 4 minutes. The machine measures bone density by detecting the extent to which bones absorb photons that are generated by very low-level x-rays. (Photons are atomic particles with no charge.) Measurements of bone mineral density are generally given as the average concentrations of calcium in areas that are scanned.

A bone density scan measures the density of bone in a person. The lower the density of a bone the higher the risk of fractures. A bone scan, along with a patient's medical history, is a useful aid in evaluating the probability of a fracture and whether any preventative treatment is needed. A bone density scan has the advantage of being painless and exposing the patient to only a small amount of radiation.

Bone density is usually measured at the hip rather than the spine or wrist, which appears to be the most predictive of hip fracture. (Hip fractures are the most dangerous fractures, particularly in women older than sixty.) The BMD in the spine may also be measured. (Spinal BMD in older people however may be misleading. Bone density in this group may increase because of compression on the spinal bones from arthritic changes in the spine. Therefore, bone density measurements may be normal or even high, but the patient may actually be at risk for fracture.)

Click the icon to see an image of a hip fracture.

Ultrasound. Ultrasound techniques measure bone density in the heels, fingers, and leg bones. In early studies, advanced ultrasound techniques, such as quantitative ultrasound (QUS), are promising for improving accuracy in predicting fractures when used with DEXA. Ultrasound itself is less expensive than DEXA and uses no radiation. Ultrasound bone tests are sometimes given at health fairs or other non-medical settings. It should be noted that these results typically vary widely from measurements of the hipbone and are not reliable when used alone.

Quantitative Computed Tomography. Quantitative computed tomography (QCT) scans, a form of CT scans, can provide highly detailed information about spinal density. Radiation doses from this technique are higher than the others. Whether QCT predicts fracture risk accurately is, however, unknown.

Determining Osteoporosis and the Risk for Fracture

Osteoporosis is diagnosed when bone density has decreased to the point where fractures will happen with mild stress, the so-called fracture threshold. This is determined by measuring bone density and comparing the results with the norm. However, low scores on bone density are not very accurate in determining fracture risk without consideration of other risk factors for fracture.

In general, doctors take the following steps to determine osteoporosis:

• Bone mineral density (BMD) is measured, typically in the hipbone, using bone densitometry.
• Measurements of BMD are given as mg/cm². This is the average concentration of bone mineral in the areas that are being scanned. In general, bone is normal if results are greater than 833 mg/cm². Low bone density (osteopenia) is between 833 and 648 mg/cm². Osteoporosis is diagnosed with results below 648 mg/cm².

These measurements still do not always indicate the true risk for fracture. The doctor also assesses risk factors and other considerations. The next step is to compare the patient's BMD to normal bone density, which is defined as the average BMD in the hipbones of premenopausal Caucasian women. (This group is used as the basis for the norm because of their high risk and greater proportion in the American population.)

The health professional then uses this comparison to determine her standard deviation (SD) from this norm. SD results are given as Z and T scores:

• A T score gives the SD of the patient in relationship to the norm in young adults. Doctors often use the T-score and other risk factors to determine the risk for fracture.
• A Z score gives the SD of the patient in relationship to the norm in her own age group. Z scores may be used to monitor the effects of treatments in women who have been diagnosed with osteoporosis.

For example, the lifetime risks for a younger woman with a specific T-score would be higher than the same scores in an older woman because the younger woman would have a longer time to lose bone density. In general, the T scores in a 55-year-old woman suggest the following degrees of risk for hip fracture.

• One standard deviation (SDs) or less below the norm indicates normal BMD. (This carries a lifetime chance for a hip fracture of up to about 20%, depending on age and other risk factors.)
• Between 1 and 2.5 SDs below normal defines osteopenia, which is low bone density. This carries between a 20 - 50% lifetime risk for fracture.
• More than 2.5 SDs predicts osteoporosis and over a 60% chance for hip fracture. Additional risk factors increase the risk. They include low weight, smoking, risks for falling, and especially a history of previous fractures. For example, in women 65 years old with low bone density but no adverse factors, the risk for fracture is 4.3% in 1 year and 28.6% over 5 years. In similar women with a previous fracture, the probability of fracture at 1 year is 11% and at 5 years is 71.8%.

Not all older women with osteoporosis develop fractures. There is some evidence that the body partially compensates after menopause by increasing bone strength, which can help offset the risk for fracture. Techniques to measure bone strength may better identify women at higher or lower risk.

Note: Because the standards are based on Caucasian women, they do not necessarily apply to men, children, or to non-Caucasian women. For example, men have a lower risk for fracture at the same SDs as women. Researchers are attempting to establish risk guidelines for these groups as well.

Laboratory Tests

Laboratory blood or urine tests for identifying certain markers of bone loss may prove to be useful in certain cases:

• High levels of the chemicals deoxypyridinoline and C-telopeptide in the blood may indicate increased risk for hip fracture. These substances are produced when bone is broken down.
• A urine test detecting a substance called N-telopeptide may indicate bone loss (although it is not associated with any risk for fracture).

Lifestyle Changes

Because osteoporosis affects such a considerable portion of the female population, total prevention may not be possible, particularly for high-risk groups. Once a woman goes through menopause and more rapid bone depletion occurs, the line between prevention and treatment blurs. Despite their lower risk for osteoporosis, men should also protect their bones with the same healthy lifestyle habits.

Exercise

Exercise is very important for slowing the progression of osteoporosis. Although mild exercise does not protect bones, moderate exercise (more than three days a week for more than a total of 90 minutes a week) reduces the risk for osteoporosis and fracture in both older men and women. Everyone who is in good health should aim for more. Exercise should be regular and life-long. Before beginning any strenuous exercise program, older patients, those at risk or those who have serious medical conditions, should talk to their doctors.

Specific exercises may be better than others, depending on the age group:

• Children should begin exercising before adolescence, since bone mass increases during puberty and reaches its peak between ages 20 and 30. Some evidence suggests that exercise may help develop bone mass in teenagers more effectively than high calcium intake. High-intensity exercises may be particularly bone-strengthening in young people. (Such regimes should not be confused with the athlete-triad -- intense competitive exercise, eating disorders, and menstrual irregularities -- that causes osteoporosis in young athletes.)
• Weight-bearing exercise applies tension to muscle and bone and, in young people, encourages the body to compensate for the added stress, increasing bone density by as much as 2 - 8% a year. In premenopausal women these exercises are very protective. (Young men need high-intensity exercises to increase bone mass.) Careful weight training is also very beneficial for elderly people, especially women.
• Regular brisk long walks improve bone density and mobility and may relieve osteoarthritic pain. High-impact exercises can be very bone-protective in young and middle-aged adults who have no precluding medical or physical conditions. Most older individuals should avoid high-impact aerobic exercises (step aerobics), which increase the risk for osteoporotic fractures. (Older people, particularly women who engage in jumping exercises should do so under supervision.) Although low-impact aerobic exercises such as swimming and bicycling do not increase bone density, they are excellent for cardiovascular fitness and should be part of a regular regimen.
• Exercises specifically targeted to strengthen the back help prevent fractures later on in life and can be beneficial in improving posture and reducing kyphosis (hunchback), even in people with existing severe conditions.
• Low-impact exercises that improve concentration, balance, and strength, particularly yoga and tai chi, have been found to decrease the risk of falling. In one study, tai chi reduced the risk of falling by almost half.

Exercise plays an important role in the retention of bone density in the aging person. Studies show that exercises requiring muscles to pull on bones cause the bones to retain and possibly gain density.

Click the icon to see an image of osteoporosis.

Calcium Supplements

For years, doctors have recommended that women take supplements of calcium plus vitamin D to help maintain bone density and reduce the risk for fractures. However, a 2006 New England Journal of Medicine study raised some questions about this approach. In the Women’s Health Initiative study, women were randomly assigned to receive either 1,000 mg of calcium carbonate plus 400 IU of vitamin D a day, or placebo. The results indicated that daily calcium and vitamin D supplements:

• Improve slightly (by 1%) hip bone density
• Prevent hip fracture, but only for women who consistently take the supplements. (Another 2006 study supported this finding.)
• Do not prevent spine or other types of fractures
• Produce a slight increase in the risk of kidney stones

The medical community has differing views on how to interpret these findings. Some doctors recommend that women over age 60 should still consider taking calcium and vitamin D for bone health. Other doctors feel that due to the risks of kidney stones, supplements are beneficial only for women (especially those over age 70) who do not get enough calcium in their diets. Ask your doctor whether you should take calcium supplements.

Appropriate Daily Doses. Evidence is unclear about the best dosage. In general the amount taken depends on age and risk factors:

• In young people, calcium intake should be 800 mg per day for children ages 3 - 8 and 1,300 mg per day for children and adolescents ages 9 - 17. Teenage girls who have a low intake of calcium in their diets should consider supplements, which can help build bone density during these critical years.
• The standard recommended dose for people over age 50 is about 1,200 mg per day, but may be higher or lower depending on risk factors. Even doses of 1,000 mg may help preserve bone in many postmenopausal women without osteoporosis, including during winter months (when bone loss is greatest). In women who have already experienced osteoporosis-related fractures, however, 1,000 mg daily may not add any protective benefits without bone-building medication.
• Some experts suggest that all pregnant women, adolescents, and those on corticosteroids take 1,000 - 1,300 mg of calcium every day.
• Breast-feeding women should have 2,000 mg per day.

Because of potential side effects with high amounts of calcium, an upper limit of 2,500 mg is recommended.

Forms of Calcium Supplements. Calcium supplements exist in different compounds, such as calcium carbonate (Caltrate, Os-Cal, Tums), calcium citrate (Citracal), calcium gluconate, and calcium lactate. Although all of these provide calcium, they have different calcium concentrations, absorption capabilities, and other actions. Their value in preserving bones depends on many different factors:

• Calcium Concentrations. Forty percent of calcium carbonate is actually calcium, whereas calcium citrate is 24% calcium, and calcium gluconate is only 9% calcium.
• Calcium Absorption Capabilities. The calcium must also be absorbed from the stomach into the bloodstream. Calcium citrate is better absorbed than many other calcium compounds. It was reported to be the first calcium supplement to preserve bone density after menopause. (Calcium citrate also increases iron absorption. Milk and other calcium compounds tend to reduce iron absorption.) One simple method for testing the absorbency of a particular brand of calcium tablet is to place it in a glass of white vinegar at full strength and check to be sure that it breaks up within 30 minutes. Taking large amounts of antacids can impair calcium absorption. Supplements should be taken after meals.

Side Effects. Calcium supplements, even at normal doses of about 1,000 mg a day, can increase the risk for kidney stones. People should be careful not to exceed the upper limit of 2,500 mg per day. (Because many commercial foods are now fortified with calcium, this upper limit may be easier to reach than people think.) Calcium may boost the effects of drugs used to treat osteoporosis.

Click the icon to see an image of kidney stones.

Although not a specific side effect of calcium, there has been much public concern about reports of a small amount of lead in calcium supplements. Although exposure to high levels of lead can cause health problems, the amount in such supplements is very small, and experts believe the amount poses no hazard.

Vitamin D and Other Vitamins

Vitamin D. Vitamin D is necessary for the absorption of calcium in the stomach and gastrointestinal tract and is the essential companion to calcium in maintaining strong bones. Vitamin D protects against osteoporosis only in combination with calcium.

Click the icon to see an image of the benefits of vitamin D.

Vitamin D is manufactured in the skin using energy from the ultraviolet rays in sunlight. It can also be obtained from dietary supplements. As a person ages, vitamin D levels decline. They also fall during winter months and when people have inadequate sunlight. Pollution may also contribute to less sunlight and declining vitamin D levels.

Click the icon to see an image of the sources of vitamin D.

Current adult guidelines recommend:

• 400 IU (10 mcg) for people between ages 50 and 60.
• 600 IU (15 mcg) for those over age 70 who do not have sufficient exposure to sunlight. (Some evidence suggests that higher doses of vitamin D -- up to 800 IU per day -- may help prevent fractures in people with osteoporosis.)

Sufficient sunlight exposure and drinking milk fortified with vitamin D supply most people’s normal needs for vitamin D. One cup of whole milk provides about 100 IU of vitamin D. Oily fish (sardines especially, also salmon, fresh tuna, mackerel) are also important dietary sources of vitamin D. Wild salmon has a much higher vitamin D content than farmed salmon.

Vitamin D is toxic in high doses. In people without vitamin D deficiencies, adding the vitamin to calcium supplements does not add any additional protection. No one should exceed the recommended daily intake of vitamin D except under the direction of a doctor.

There is some concern that many people may be deficient in vitamin D as more individuals avoid sunlight to prevent skin cancers and increase their intake of milk products, such as yogurt and skim milk, which may have little vitamin D. Such individuals may need to take supplements. People with darker skin are at higher risk for deficiencies than those with lighter skin.

Vitamin D derivatives are being investigated for treating osteoporosis. Calcitriol (Calcijex, Rocaltrol), for example, is a prescription-form of vitamin D that can increase bone mass and decrease the rate of spinal fractures. However, calcitriol increases the risk for high blood calcium levels (hypercalcemia) and requires frequent monitoring. Other vitamin D analogues under investigation include doxercalciferol (Hectorol), 22-oxacalcitriol (Maxacalcitol), cholecalciferol, and alfacalcidol.

Vitamin K. Vitamin K has properties that protect bone and prevent fracture. Intestinal bacteria produce vitamin K, and the vitamin is found in leafy vegetables, so deficiencies are rare, although there is some evidence that people may not be consuming enough of this nutrient. Vitamin K affects blood clotting, and supplements are not recommended without specific doctor instruction. Vitamin K2 (menatetrenone), a form of vitamin K, may help prevent fractures in people with osteoporosis.

Click the icon to see an image of the benefits of vitamin K.

Click the icon to see an image of the sources of vitamin K.

Vitamin B12. One study reported that in people with osteoporosis and pernicious anemia, taking vitamin B12 (which is used to treat the anemia) also increased bone density.

Vitamin C and E. There has been some positive association between vitamin C and E intake and bone density. For example, a 2001 study reported better bone health in women who were taking estrogen therapy as well as calcium and vitamin C. More evidence is needed, however, to prove any direct benefits.

Click the icon to see an image of the benefits of vitamin C.

Click the icon to see an image of the sources of vitamin C.

Click the icon to see an image of the benefits of vitamin E.

Click the icon to see an image of the sources of vitamin E.

Vitamin A. High amounts of dietary vitamin A reduce bone density and may even increase the risk for fracture in postmenopausal women. (A form of vitamin A, retinoic acid, has been found to stimulate bone breakdown.)

Dietary Recommendations

The DASH Diet and Low Sodium. Perhaps a good general approach for people at risk for osteoporosis (or almost any adult) is the DASH diet plus sodium (salt) restriction. The DASH (Dietary Approaches to Stop Hypertension) diet is used to help people with hypertension maintain healthy blood pressures. A 2003 study also reported that it might help protect bones and improve cholesterol levels. This diet not only is rich in important nutrients and fiber but also includes foods that contain far more potassium, calcium, and magnesium, than are found in the average American diet. All of these minerals are important for bone protection. The dietary recommendations are as follows:

• Avoid saturated fat (although include calcium-rich dairy products that are no- or low-fat). When choosing fats, select monounsaturated oils, such as olive or canola oils. These fats are also found in some fish. Although no one wants to be overweight, even a slight excess of fat helps protect bones. In fact, in one 2000 study, women who ate more fat in their diet were, on average, better able to absorb calcium than were women who had been put on a low-fat, high-fiber diet.
• Choose whole grains over white flour or pasta products. Include nuts, seeds, or legumes (dried beans or peas) daily.
• Choose fresh fruits and vegetables every day. Many of these foods are rich in potassium, magnesium, and other minerals that are important for bone (as well as heart) protection.
• Choose protein preferably from fish, poultry, or soy products. Soy in combination with fiber-rich foods or supplements may have specific benefits. Oily fish may also be particularly beneficial. They contain omega-3 fatty acids, which have been associated with heart and nerve protection.

Salt Restriction. Reducing salt may protect both the heart and the bones. High sodium intake interferes with calcium retention. Note: Fast foods and commercial snacks are usually high in sodium and have been linked with weak bones.

Dairy Products and Calcium-Rich Foods. Although some studies have reported that dairy products benefit the bones, it is not entirely clear if high-calcium diets reduce the risk for fractures compared to adequate intake of vitamin D. Until more is known, people should be sure their diets have sufficient calcium. Dietary calcium is available from many good sources.

• Milk and Dairy Products. The best source of calcium in the diet is from milk fortified with vitamin D. Four glasses of milk provide about 1,200 mg of calcium. (Skim milk and yogurt products, unfortunately, are often low in vitamin D, which is important for calcium absorption.) According to a 2003 study, girls who have low milk intake increase their risk for fracture in adulthood. One report even suggests that milk proteins actually slow bone break down. It is not clear, however, if drinking milk after menopause offers any significant bone protection.
• Other Calcium-Rich Foods. Other calcium-rich foods include shrimp, canned salmon or sardines, black strap molasses, calcium-fortified tofu, and almonds. A number of commercial foods, including orange juice and some cereals, are now calcium fortified. Dark green vegetables (broccoli, kale, turnip greens) are rich in calcium but little of it is absorbed (kale is best).

Click the icon to see an image of milk and the facial bones.

Mineral-Rich Fruits and Vegetables.

• Potassium. Potassium may be very important for strong bones and may help counteract negative effects of high-protein diets. Potassium-rich fruits include bananas, oranges, prunes, and cantaloupes, and vegetables that contain potassium include carrots, spinach, celery, alfalfa, mushrooms, lima beans, potatoes, avocados, and broccoli.
• Magnesium. Some studies have observed that low levels of magnesium may contribute to thinning bones. Some studies suggest that magnesium supplements help suppress the cycle that leads to bone loss. Experts recommend 350 mg a day for supplements. However, excessive magnesium may be harmful in people with diabetes or kidney disease. Foods rich in magnesium include dairy products, spinach, potatoes, beets, nuts, sole, and halibut.
• Other Minerals. Phosphorous, boron, and zinc have also been associated with bone protection.

Protein. Both low and high protein intake has been associated with bone loss. Protein deficiencies appear to trigger hormonal changes that increase bone breakdown. Protein may also be important for frail older people for improving muscle strength. On the other hand, high protein intake increases urinary calcium loss, which can impair bone density in people with low calcium diets. High protein diets, however, do not appear to cause bone loss if calcium intake is also high. The bottom line, then, is to have sufficient protein but to balance this with plenty of calcium- and other mineral-rich foods.

The protein source (meat, soy, or fish) may have some effect on bone density, although the effects are not clear. Studies are mixed on whether protein from meat has a positive or negative effect on bone loss. A 2003 study found no differences in bone calcium levels between women on high- or low-meat diets. In any case, the best sources of protein for bone protection may be from oily fish or soy.

• Choosing protein from fish (especially oily fish such as salmon, mackerel, fresh tuna, herring) may be a good option. Oily fish are high in vitamin D, which is bone protective. (Note: American brands of canned tuna generally contain no significant amounts of vitamin D.) Such fish are also heart protective.
• Studies on soy have suggested some modest protection against bone loss. Soy is high in estrogen-like plant chemicals called isoflavones, which may actually improve bone health in older women. (However, other studies indicate that soy has no effect on bone density in healthy premenopausal women.) Soy food products, such as tofu, that also contain calcium may be particularly beneficial. In such cases, 3 oz of tofu supply 60% of daily calcium requirements.

Alcohol. Alcohol has different effects on bones depending on how much is consumed. A 2000 study found that women older than age 65 who drank one to two drinks (1 - 2 oz) of alcohol weekly had higher bone density than non-drinkers. Alcohol in moderate amounts may reduce parathyroid hormone and increase estrogen levels. Excessive drinking, however, has been associated with brittle bones.

Cola, Coffee, Tea and Caffeine. A 2002 study suggested that drinking tea regularly may help protect bones. Nevertheless, there has been some concern that caffeine consumption, particularly from coffee, may increase calcium levels in urine and reduce levels in the body. In one trial, consumption of lots of coffee, (9 or more cups per day, was associated with an increased risk of hip fractures in women, but not in men. However, not all studies support a risk. Some evidence, in fact, suggests that caffeine may pose a danger for bone loss only in elderly thin women -- but not in those who have normal or high weight. Drinking carbonated beverages, particularly cola, may increase the risk for bone fractures in people with low bone density.

Oral Contraceptives

The effect of OCs on bone density is unclear and may depend on dosage levels, the specific formulas, and timing. A Canadian study that followed a group of young women found that OCs resulted in lower bone density and higher risk for fractures, possibly because taking OCs at younger ages interferes with achieving peak bone mass. Some evidence suggests, however, that low-dose OCs may protect against bone loss in women during the perimenopausal period. In addition, specific progestins (such as norethindrone or norgestimate) may be bone protective.

Quit Smoking

Everyone who smokes should quit. The risk for osteoporosis from smoking appears to diminish after quitting.

Preventing Falls and Fractures

An important component in reducing the risk for fractures is preventing falls. Risk factors for falling include:

• Slow walking
• Inability to walk in a straight line
• Certain medications (such as tranquilizers and sleeping pills)
• Low blood pressure when rising in the morning
• Poor vision

Recommendations for preventing falls or fractures from falls in elderly people include:

• Exercise to maintain strength and balance if there are no conflicting medical conditions. In one study of older people, this was the single best intervention for preventing falls.
• Do not use loose rugs on the floors.
• Move any obstructions to walking, such as loose cords or very low pieces of furniture, away from traveled areas.
• Rooms should be well lit.
• Have regular eye checkups.
• Try wearing hip pads. Hip pads are specially designed to protect hipbones against falls and are worn under clothing. Evidence on their protection against fractures is weak, however, particularly since compliance is poor. Nevertheless, newer hip pads that are thinner and made with newer materials may be helpful and more appealing.
• Wear thinner, hard-soled shoes. Studies indicate these shoes are just as comfortable as the popular resilient-soled footwear, but they may be difficult to find. Soft-soled high-resilient so-called athletic footwear may contribute to impaired balance and dangerous falls, in part, because these cushioned shoes offer less stability.

Medications

Major drug therapies now exist for treating osteoporosis. Unfortunately, studies continue to report that doctors fail to evaluate and adequately treat both men and women for this condition, even after a fracture. In a 2002 study of Caucasian women over age 60, fewer than 2% were evaluated for osteoporosis or spinal fracture by their doctors. Among those who were diagnosed, only 36% received appropriate medication. Two studies in 2003 further reported that among adults who had sustained fractures, less than 5% of men and fewer than half of women were evaluated and treated according to recommended guidelines. In one of the studies, only 24% of women were given treatments for osteoporosis after a fracture. In both studies, the older a woman was the less likely she was to have adequate evaluation or treatment.

Drugs Used to Treat Osteoporosis. There are two types of drugs used to treat osteoporosis:

• Antiresorptive Drugs. Antiresorptives include bisphosphonates, hormone replacement therapy, SERMs, and calcitonin. Bisphosphonates are the standard drugs used for osteoporosis. These drugs block resorption (bone break down) and so slow the rate of bone remodeling, but they cannot rebuild bone. In fact, because resorption and reformation occur naturally as a continuous process, blocking resorption may eventually also reduce bone formation.
• Anabolic, or Bone-Forming, Drugs. Drugs that rebuild bone are known as anabolics. The primary anabolic drug is low-dose parathyroid hormone (PTH), which is administered as injections. It is proving to be very effective in restoring bone and preventing fractions. PTH is still relatively new, and long-term effects are still unknown. Fluoride is another bone-building drug, but it has limitations and is not commonly used.

Both types of drugs are effective in preventing bone loss and fractures, although they vary in their effectiveness and safety.

Bisphosphonates

Bisphosphonates are anti-resorptive drugs. That means they prevent bone breakdown. They are now the primary drugs for preventing and treating osteoporosis. They can help reduce the risk of both spinal and hip fractures, including in patients who have had prior bone breaks.

Studies indicate that these drugs are effective and safe for at least 10 years. Eventually, however, bone loss progresses with bisphosphonates. This may be due to the fact that bone breakdown (resorption) is one of two phases in a continuous process of bone resorption and reformation. Over time, just blocking resorption will interrupt this process and impair the second half of the process -- bone formation. Some experts think that this problem may be overcome by building bone for a couple of years with parathyroid hormone (PTH), then following this treatment with bisphosphonates to prevent the breakdown of bone. (Administering the two drugs simultaneously is not effective because bisphosphonates interfere with the way PTH works.)

Candidates. National Osteoporosis Foundation guidelines recommend that the following people should take or consider bisphosphonates:

• Women with a below-normal bone density of 2.5 SD or greater and no history of fractures.
• Women with below-normal bone density 1 SD or more and a history of fractures

Brands. Bisphosphonates are available in different forms:

• Oral bisphosphonates. These pills include alendronate (Fosamax), risedronate (Actonel), and ibandronate (Boniva). Alendronate and risedronate are taken once a week. In 2005, ibandronate was approved as the first once-monthly pill. Risedronate is also available in a pill that contains calcium. Both risedronate and alendronate are approved for men as well as women.
• Intravenous bisphosphonates. In 2006, ibandronate (Boniva) was approved as the first intravenous form of bisphosphonate. It is given as an injection every 3 months in a doctor’s office for treatment of osteoporosis. This injectable form is an alternative for patients who may have difficulty swallowing pills or sitting upright after oral bisphosphonate treatment. Researchers are also investigating Reclast, a bisphosphonate that would be administered once a year as a 15-minute infusion. Reclast contains zoledronic acid, a drug used for treating cancer-related bone problems.

Side Effects. Bisphosphonates’ most distressing side effects are gastrointestinal problems, particularly stomach cramps and heartburn. These symptoms are very common and occur in nearly half of all patients. Other side effects may include irritation of the esophagus (the tube that connects the mouth to the stomach), and ulcers in the esophagus or stomach. Some patients may experience muscle and joint pain. To avoid stomach problems, doctors recommend:

• Take the pill on an empty stomach in the morning with 6 - 8 ounces of water (not juice, or carbonated or mineral water).
• After taking the pill, remain in an upright position. Do not eat or drink for at least 30 - 60 minutes. (Check your drug’s dosing instructions for exact time.)
• If you develop chest pain, heartburn, or difficulty swallowing, stop taking the drug and see your doctor.

Osteonecrosis (bone death) of the jaw is a rare side effect that has occurred mainly in patients with cancer who received intravenous bisphosphonates. Many of these patients had major dental procedures before developing osteonecrosis. However, this bone decay condition has also been reported in some patients who have taken oral bisphosphonates (mainly alendronate). Symptoms may include jaw pain or swelling, gum infections, and poor healing of the gums. Talk to your doctor or dentist if you experience any jaw or gum discomfort while taking a bisphosphonate drug.

SERMs

Raloxifene (Evista) belongs to a class of drugs called selective estrogen-receptor modulators (SERMs). These drugs are similar, but not identical, to estrogen. Raloxifene provides the bone benefits of estrogen without increasing the risks for estrogen-related breast and uterine cancers. In fact, doctors are studying how raloxifene may help prevent breast cancer in women who are at high-risk for this disease.

While there are many SERM drugs, raloxifene is the only SERM approved for treatment and prevention of osteoporosis. It should only be taken by postmenopausal women who have or are at risk for osteoporosis. Studies indicate that raloxifene can stop the thinning of bone and help build better quality and stronger bone.

A thrombus is a blood clot that forms in a vessel and remains there. An embolism is a clot that travels from the site where it formed to another location in the body. Thrombi or emboli can lodge in a blood vessel and block the flow of blood in that location, depriving tissues of normal blood flow and oxygen. This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area.

Side Effects. Raloxifene increases the risk for blood clots in the veins. Because of this side effect, raloxifene also increases the risk for stroke (but not other types of heart disease). These side effects are rare, but very serious. Women should not take this drug if they have a history of blood clots, or have certain risk factors for stroke and heart disease. More common mild side effects include hot flashes and leg cramps.

Calcitonin

Produced by the thyroid gland, natural calcitonin regulates calcium levels by inhibiting the osteoclastic activity, the breakdown of bone. The drug version is derived from salmon and is available as a nasal spray (Miacalcin) and an injected form (Calcimar). Calcitonin is not used to prevent osteoporosis. It treats osteoporosis. It may be effective for spinal protection (but not hip) in both men and women. Calcitonin may be an alternative for patients who cannot take a bisphosphonate or SERM. It also appears to help relieve bone pain associated with established osteoporosis and fracture.

Side Effects. Side effects include headache, dizziness, anorexia, diarrhea, skin rashes, and edema (swelling). The most common adverse effect experienced with the injection is nausea, with or without vomiting. This occurs less often with the nasal spray. The nasal spray may cause nosebleeds, sinusitis, and inflammation of the membranes in the nose. Also, because calcitonin is a protein, a large number of people taking the drug develop resistance or allergic reactions after long-term use.

Parathyroid Hormone (PTH)

Although high persistent levels of parathyroid hormone can cause osteoporosis, daily injections of low and intermittent doses of this hormone actually stimulate bone production and increase bone mineral density. In clinical studies, teriparatide (Forteo), a drug made from selected amino acids found in parathyroid hormone, reduced the risk for spinal and non-spinal fractures by 50 - 65%. It may prove to be a very useful drug for men with osteoporosis. Unlike most treatments for osteoporosis, including bisphosphonates, the benefits may persist even after the injections have been stopped.

Although the treatment requires injections, researchers are investigating a nasal spray version of PTH. In addition to easing patient discomfort, there is some preliminary evidence that nasal-administered PTH may be better absorbed than injections. Side effects of PTH are generally mild and include nausea, dizziness, and leg cramps. No significant complications have been reported to date.

Early animal studies did report bone tumors in mice that were given parathyroid long-term. Such effects have not been observed in humans to date. However, people with Paget disease, (a disorder in which bone thickens but also, oddly, weakens), should not take parathyroid hormone, since they are at higher than normal risk for bone tumors.

Hormone Replacement Therapy

Hormone replacement therapy (HRT) is sometimes used to prevent osteoporosis. A Women’s Health Initiative (WHI) study found that women who received estrogen, or estrogen plus progestin, therapy had fewer fractures than women who received placebo.

However, WHI studies have also shown that these hormones increase the risk for breast cancer, blood clots, strokes, and heart attacks. For this reason, women need to balance the benefits that HRT has on bone-loss protection, with the risks it carries for other serious health conditions. The FDA recommends that women first try other medications for prevention of osteoporosis.

HRT is available in many different forms, including pills and skin patches. [For more information, see In-Depth Report #40: Menopause.]

Other Investigational Drugs

• Diuretics. Diuretics are used to treat high blood pressure. They have different effects on osteoporosis depending on the type, with loop diuretics associated with bone loss. Thiazide diuretics, on the other hand, protect against fracture, and may prove to be particularly useful for men at risk for osteoporosis. Protection against fracture lasts only during the time they are used. There are many thiazides and thiazide-related drugs. Some common ones are chlorothiazide (Diuril), chlorthalidone (Hygroton), indapamide (Lozol), and hydrochlorothiazide (Esidrix, HydroDiuril). Researchers are also studying how the combination of beta-blockers (another drug used to treat high blood pressure) and thiazide diuretics may offer bone protection.
• Strontium. Strontium, a chemical element found in bone, may help increase bone formation and decrease bone resorption.

Treatment

Conservative Treatments

Nonsurgical treatments for fractures include braces, plaster cases, and manipulation of the fracture. Such approaches have not been well studied to determine an optimal method, and patients should discuss all options with their doctors.

Reconstructive Surgery

Reconstructive surgery is usually used for hip fractures and should be performed within 48 hours, assuming the patient has no other complicating medical conditions. After surgery, the patient should be mobilized within the first day. In one study, protein supplements helped people with hip fractures recover more quickly and reduced bone loss.

Percutaneous Vertebroplasty and Variants for Osteoporosis Fractures in the Spine

Percutaneous vertebroplasty and kyphoplasty are surgical procedures used to lessen pain. Research to date suggests that they are safe and provide pain relief for many patients. In some cases they may increase height. There have been few controlled trials, however, and more research is needed to determine long-term effects.

Percutaneous Vertebroplasty. Percutaneous vertebroplasty involves the injection of a cement-like bone substitute into damaged vertebrae. It is proving useful for stabilizing the spine and relieving pain in patients with spinal compression fractures due to osteoporosis or cancer. Success rates of over 90% have been reported. Serious complications occur in fewer than 1% of cases.

Kyphoplasty. Kyphoplasty is a variant of percutaneous vertebroplasty that may help prevent kyphosis (hunchback) in patients whose spines have collapsed. The procedure inserts a balloon into the fractured vertebrae. As the balloon inflates, the spine is moved upward, to its original location. The balloon is then removed, and the bone and the core of the newly-erect vertebrae are filled with cement. In one 2003 study, short-term symptom relief improved by 70% and was immediate. Long-term effectiveness is not yet known.

Resources

• www.nof.org -- National Osteoporosis Foundation
• www.osteo.org -- National Institutes of Health, Osteoporosis and Related Bone Diseases
• www.menopause.org -- North American Menopause Society
• www.asbmr.org -- American Society for Bone and Mineral Research
• www.niams.nih.gov -- National Institute of Arthritis and Musculoskeletal and Skin Diseases

References

Barrett-Connor E, Mosca L, Collins P, Geiger MJ, Grady D, Kornitzer M, et al. Effects of raloxifene on cardiovascular events and breast cancer in postmenopausal women. N Engl J Med. 2006 Jul 13;355(2):125-37.

Kern LM, Powe NR, Levine MA, Fitzpatrick AL, Harris TB, Robbins J, et al. Association between screening for osteoporosis and the incidence of hip fracture. Ann Intern Med. 2005 Feb 1;142(3):173-81.

LaCroix AZ, Gass M, Wallace RB, Robbins J, Lewis CE, Bassford T, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med. 2006 Feb 16;354(7):669-83.

Neuner JM, Binkley N, Sparapani RA, Laud PW, Nattinger AB. Bone density testing in older women and its association with patient age. J Am Geriatr Soc. 2006 Mar;54(3):485-9.

Prince RL, Devine A, Dhaliwal SS, Dick IM. Effects of calcium supplementation on clinical fracture and bone structure: results of a 5-year, double-blind, placebo-controlled trial in elderly women. Arch Intern Med. 2006 Apr 24;166(8):869-75.

Ruggiero SL, Mehrotra B, Rosenberg TJ, Engroff SL. Osteonecrosis of the jaws associated with the use of bisphosphonates: a review of 63 cases. J Oral Maxillofac Surg. 2004 May;62(5):527-34.

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