Osteoporosis

Osteoporosis is a condition characterized by a decrease in the density of bone, decreasing its strength and resulting in fragile bones.

Osteoporosisis a condition characterized by a decrease in the density of bone, decreasing its strength and resulting in fragile bones.Osteoporosisliterally leads to the abnormally porous bone that is compressible, like a sponge. This disorder of the skeleton weakens the bone and results in frequentfractures(breaks) in the bones.Osteopenia, by definition, is a condition of bone that is slightly less dense than normal bone but not to the degree of bone inosteoporosis.

Normal bone is composed of protein, collagen, and calcium, all of which give bone its strength. Bones that are affected by osteoporosis can break (fracture) with relatively minor injuries that normally would not cause a bone tofracture. Thefracturecan be either in the form of cracking (as in ahip fracture) or collapsing (as in a compression fracture of the vertebrae of the spine). The spine, hips, ribs, and wrists are common areas of bone fractures from osteoporosis although osteoporosis-related fractures can occur in almost any skeletal bone.

• In the U.S., 44 million people have a lowbone density(10 million have osteoporosis, and 34 million haveosteopenia). This amounts to 55% of the U.S. population aged 50 years and older.
• One in two Caucasian women will fracture a bone due to osteoporosis in her lifetime.
• In the U.S., direct health care costs from osteoporosis fractures amount to a billion dollars, without even taking into account the indirect costs, such as lost days at work and productivity.
• Approximately 20% of those who experience a hip fracture will die in the year following the fracture.
• One-third of hip-fracture patients are discharged to anursinghome within the year after fracture.
• Only one-third of hip-fracture patients regain their pre-fracture level of function.

With theagingof America, the number of people with osteoporosis-related fractures will increase exponentially. Thepain, suffering, and overall impact on health and economic costs will be enormous.

Osteoporotic bone fractures are responsible for considerablepain, decreased quality of life, lost workdays, and disability.

• Up to 30% of patients suffering a hip fractures will require long-term nursing-home care.
• Elderly patients can developpneumoniaandblood clotsin the leg veins that can travel to thelungs(pulmonary embolism) due to prolonged bed rest after the hip fracture.
• Osteoporosis has even been linked with an increased risk of death. Some 20% of women with a hip fracture will die in the subsequent year as an indirect result of the fracture.
• In addition, once a person has experienced a spine fracture due to osteoporosis, he or she is at a very high risk of suffering another such fracture in the near future (next few years).
• About 20% ofpostmenopausalwomen who experience a vertebral fracture will suffer a new vertebral fracture of a bone in the following year.

The following are 22 factors that will increase the risk of developing osteoporosis:

1. Female gender
2. Caucasian or Asian race
3. Thin and small body frame
4. Family history of osteoporosis (for example, having a mother with an osteoporotic hip fracture doubles your risk of hip fracture)
5. Personal history of fracture as an adult
6. Cigarette smoking
7. Excessivealcoholconsumption
8. Lack ofexercise
9. Dietlow in calcium
10. Poornutritionand poor general health, especially associated with chronic inflammation or bowel disease
11. Malabsorption (nutrients are not properly absorbed from the gastrointestinal system) from bowel diseases, such asceliac spruethat can be associated with skin diseases, such asdermatitisherpetiformis
12. Low estrogen levels in women (which may occur inmenopauseor with early surgical removal of both ovaries)
13. Low testosteronelevels in men (hypogonadism)
14. Chemotherapy can cause earlymenopausedue to its toxic effects on the ovaries
15. Amenorrhea(loss of the menstrual period) in young women is associated with low estrogen and osteoporosis; amenorrhea can occur in women who undergo extremely vigorousexercisetraining and in women with very low body fat (for example, women withanorexia nervosa)
16. Chronic inflammation, due to chronic inflammatoryarthritisor diseases, such as粘膜分泌物toid arthritisorliverdiseases
17. Immobility, such as after astroke, or from any condition that interferes withwalking
18. Hyperthyroidismis a condition wherein too muchthyroid hormoneis produced by the thyroid gland (as inGrave's disease) or is ingested as thyroid hormone medication
19. Hyperparathyroidismis a disease wherein there is excessive parathyroid hormone production by the parathyroid gland, a small gland located near or within the thyroid gland. Normally, the parathyroid hormone maintains blood calcium levels by, in part, removing calcium from the bone. In untreated hyperparathyroidism, the excessive parathyroid hormone causes too much calcium to be removed from the bone, which can lead to osteoporosis.
20. Whenvitamin Dis lacking, the body cannot absorb adequate amounts of calcium from thedietto prevent osteoporosis.Vitamin D deficiencycan result from dietary deficiency, lack of sunlight, or lack of intestinal absorption of the vitamin such as occurs inceliac sprueandprimary biliary cirrhosis.
21. Certain medications can cause osteoporosis. These medicines include long-term use ofheparin(a blood thinner), antiseizure medicine such asphenytoin(Dilantin) and phenobarbital, and long-term use of oralcorticosteroids(such asprednisone).
22. Inheriteddisorders of connective tissue, including osteogenesis imperfecta,homocystinuria, osteoporosis-pseudoglioma syndrome, and skin diseases, such asMarfan syndromeandEhlers-Danlos syndrome(These causes of hereditary secondary osteoporosis each are treated differently.)

Osteoporosis can be present without any symptoms for decades because osteoporosis doesn't cause symptoms until bone breaks (fractures). Moreover, some osteoporotic fractures may escape detection for years when they do not cause symptoms. Therefore, patients may not be aware of their osteoporosis until they suffer a painful fracture.

• The symptom associated with osteoporotic fractures usually is pain; the location of the pain depends on the location of the fracture.
• The symptoms of osteoporosis in men are similar to the symptoms of osteoporosis in women.

9 osteoporosis symptoms and signs

1. Fractures of the spine (vertebra) can cause severe "band-like" pain that radiates from the back to the sides of the body.
2. Over the years, repeated spinal fractures can lead to chroniclower back pain.
3. People experience the loss of height and/or curving of the spine due to the collapse of the vertebrae. The collapse gives individuals a hunched-back appearance of the upper back, often called a "dowager hump" (kyphosis) because it commonly is seen in elderly women.
4. Breathingdifficulty
5. Receding gumsdue to bone loss
6. Sloping shoulders
7. Curvature of the lower spine
8. A fracture that occurs during the course of normal activity is called a minimaltrauma, orstress fracture. For example, some patients with osteoporosis developstressfractures of thefeetwhile walking or stepping off a curb.
9. 髋部骨折通常发生由于歧视l. With osteoporosis, hip fractures can occur as a result of trivial slip-and-fall accidents. Hip fractures also may heal slowly or poorly after surgical repair because of poor healing of the bone.

Bone mass (bone density) is determined by the amount of bone present in the skeletal structure. Generally, the higher the bone density, the stronger the bones. Bone density is greatly influenced by genetic factors, which in turn are sometimes modified by environmental factors and medications. For example, men have a higher bone density than women, and African Americans have a higher bone density than Caucasian or Asian Americans.

• Normally, bone density accumulates during childhood and reaches a peak by around age 25.
• Bone density then is maintained for about 10 years. After age 35, both men and women will normally lose 0.3%-0.5% of their bone density per year as part of theagingprocess.

Estrogen is important in maintaining bone density in women. When estrogen levels drop aftermenopause, loss of bone density accelerates.

• During the first 5-10 years after menopause, women can suffer up to 2%-4% loss of bone density per year!
• This is predominantly attributed to insufficient estrogen and can result in the loss of up to 25%-30% of their bone density during that time period.
• Accelerated bone loss after menopause is a major cause of osteoporosis in women, referred to as postmenopausal osteoporosis. This is true even in women who seem to otherwise have normal health.

The National Osteoporosis Foundation guidelines state that there are several groups of people who should consider DXA testing for proper diagnosis of bone health:

• All postmenopausal women below age 65 who have risk factors for osteoporosis
• All women aged 65 and older
• Postmenopausal women with fractures, although this is not mandatory because treatment may well be started regardless of bone density
• For women with any of more than 50 medical conditions associated with osteoporosis; a primary care physician can scan a patient's list of medical illnesses to determine if one of these conditions is present (see causes above)
• Women whose decision to begin treatment for osteoporosis might be aided by bone density testing to determine the presence or absence of osteoporosis or osteopenia

The National Osteoporosis Foundation guidelines state that bone-density testing does not need to be performed if a person has a known osteoporotic fracture because the patient will be treated for osteoporosis with or without a bone-density study. In addition, bone-density testing is not appropriate if the person undergoing the test is not willing to take treatment based on the results. Therefore, if bone-density testing is done, it should be performed on people willing to take some specific action to improve their bone health based on the results.

X-rays can reveal osteoporosis.

A routine X-ray can reveal osteoporosis of the bone because the bones appear much thinner and lighter than normal bones. Unfortunately, by the timeX-rayscan detect osteoporosis, at least 30% of the bone has already been lost. In addition, X-rays are not accurate indicators of bone density. Thus, the appearance of the bone on X-ray often is affected by variations in the degree of exposure of the X-ray film.

The National Osteoporosis Foundation, the American Medical Association, and other major medical organizations recommend a dual-energy X-ray absorptiometry scan (DXA, formerly known asDEXA) be used for the diagnosis of osteoporosis. DXA typically measures bone density in the hip, the spine, and the forearm. The test takes only 5-15 minutes to perform, exposes patients to very littleradiation(less than one-tenth to one-hundredth of the amount used on a standardchest X-ray), and is quite precise.

病人的骨密度是相比average peak bone density of young adults of the same sex and race. This score is called the "T score" or T-score, and it expresses the bone density in terms of the number of standard deviations (SD) below peak young adult bone mass.

• Osteoporosis is defined as a bone density T score of -2.5 or below.
• Osteopenia (between normal and osteoporosis) is defined as a bone density T score between -1 and -2.5.

It is important to note that while osteopenia is considered a lesser degree of bone loss than osteoporosis, it nevertheless can be of concern when it is associated with other risk factors (such assmoking, cortisone steroid usage,粘膜分泌物toid arthritis, family history of osteoporosis, etc.) that can increase the chances for developing vertebral, hip, and other fractures. In this setting, osteopenia may require medication as part of the treatment program.

Health care professionals who treat osteoporosis include

• generalists and internists as well as gynecologists,
• endocrinologists,
• 粘膜分泌物tologists, and,
• for fractures, bone surgeons (orthopedists).

The goal of the treatment of osteoporosis is thepreventionof bone fractures by reducing bone loss or, preferably, by increasing bone density and strength. Although early detection and timely treatment of osteoporosis can substantially decrease the risk of future fractures, none of the available treatments for osteoporosis are complete cures. In other words, it is difficult to completely rebuild bone that has been weakened by osteoporosis. Therefore, prevention of osteoporosis is as important as treatment. The following are osteoporosis treatment and prevention measures for optimal health of the bone:

1. Lifestyle changes, including quittingcigarette smoking,减少过度alcohol intake, exercising regularly, and consuming a balanced diet with adequate calcium andvitamin D
2. Medications that stop bone loss and increase bone strength, such asalendronate(Fosamax),risedronate(Actonel),raloxifene(Evista),ibandronate(Boniva),calcitonin(Calcimar), zoledronate (Reclast), and denosumab (Prolia)
3. Medications that increase bone formationsuch as teriparatide (Forteo)

In choosing a medication for osteoporosis, a physician will consider all aspects of a patient's medical history as well as the severity of the osteoporosis.

If a postmenopausal woman has other menopausal symptoms such ashot flashesandvaginal dryness,HRTwill be the proper choice for these menopausal symptoms as well as for the prevention of osteoporosis. After the menopausal symptoms have passed, some other nonestrogen prescription medication will be considered for the longer term.

If the prevention and treatment of osteoporosis is the only issue under consideration, then bisphosphonates such as alendronate, ibandronate, or risedronate are more effective than menopausalhormone therapyin preventing osteoporotic fractures and less likely to be associated with substantial adverse effects. So far, bisphosphonates are the most well-studied and effective category of prescription medication for treating postmenopausal osteoporosis.

A few serious esophageal conditions preclude the use of oral bisphosphonates, specifically esophageal stricture orachalasia. In these two conditions, it is likely that the bisphosphonate tablets will be retained in theesophagusand lead to esophageal inflammation, ulceration, and scarring. Caution often is advised for people withdysphagia(trouble swallowing) because thedysphagiamay be a manifestation of a problem in the esophagus that will cause the bisphosphonate tablets to get stuck. Caution also is advised when there isgastritis, duodenitis, or ulcers because of the possibility that the bisphosphonate will aggravate the inflammation associated with these conditions. Any worsening of gastrointestinal symptoms should be reported immediately, but the vast majority of people tolerate bisphosphonates without symptoms when the prescribing directions are followed carefully. Fortunately,GERDorheartburn是常见的,并非withholdin的理由g bisphosphonates but they are considered when selecting the optimal treatment for an individual. Prescribing directions should be followed carefully. Moreover, intravenous bisphosphonates, such as zoledronate (Reclast) or injectable denosumab (Prolia), may be given to those with esophageal strictures,achalasia, dysphagia, or gastrointestinal side effects from oral bisphosphonates.

In patients withGERDor who have symptoms of heartburn, risedronate may prove to cause less irritation to the esophagus than alendronate, but now intravenous bisphosphonates, such as zoledronate may be preferred.

Calcitonin is a weaker antiresorptive medication than bisphosphonates. It is reserved for patients who cannot take or will not consider taking other medications. Raloxifene also is a weaker medication for improving bone density or preventing fractures as compared to estrogen or bisphosphonates. In patients with moderate to severe osteoporosis, it is advisable to use the more potent antiresorptive medications (bisphosphonates). In addition, the safety and effectiveness of more than 3 years of raloxifene, or more than 24 months of teriparatide, have not been well studied.

Estrogen replacementand raloxifene differ in their side effects and also in their effects oncholesterol levels. For example, raloxifene does not raise the "good"HDL cholesterolbut estrogen replacement does. Both estrogen and raloxifene lower the "bad"LDL cholesterol.

Estrogen hormone therapy after menopause (previously referred to ashormone replacement therapyor HRT) has been shown to prevent bone loss, increase bone density, and prevent bone fractures. It is useful in preventing osteoporosis in postmenopausal women. Estrogen is available orally (Premarin,Estrace,Estratest, and others) or as a skin patch (Estraderm, Vivelle, and others).

Estrogen also is available in combination withprogesteroneas pills and patches. Progesterone is routinely given along with estrogen to prevent uterinecancerthat might result from estrogen use alone. Women who have had ahysterectomy(surgical removal of the uterus) may take estrogen alone since they no longer have a uterus to become cancerous. Nasally delivered estrogen and lower-dose combination pills of estrogen and progesterone are also being studied. However, due to adverse effects of HRT, such as increased risks ofheart attack,stroke, blood clots in the veins, andbreast cancer; HRT is no longer recommended for long-term use in the therapy of osteoporosis. Rather, HRT is used short-term to relieve menopausalhot flashes.

Every woman needs to have an individualized discussion regarding HRT with her doctor because each woman will place a different weight on the risks and benefits of the treatment.

The controversy of bone density testing in patients already taking osteoporosis medication

The American Medical Association and other reputable medical organizations recommend that repeat bone density testing (DXA scans)notbe done for monitoring osteoporosis treatment or prevention on a routine basis. It is sometimes difficult to know just how to use repeated bone density measurements during therapy. Here are a few of the most important reasons:

1. Bone density changes so slowly with treatment that the changes are smaller than the measurement error of the machine. In other words, repeat DXA scans cannot distinguish between a real increase in bone density due to treatment and a mere variation in measurement from the machine itself.
2. 骨质疏松症治疗的真正目的是decrease future bone fractures. There is no good correlation between increases in bone density with decreases in fracture risks with treatment. For example, alendronate has been shown to decrease fracture risk by 50% but only to increase bone density by a few percent. In fact, most of the fracture reduction with raloxifene is not explained by raloxifene's effects onbone mineral density.
3. One density measurement taken during treatment will not help the doctor plan or modify treatment. For example, even if theDXA scanshows continued deterioration in bone density during treatment, there is not yet research data demonstrating that changing a medication, combining medications, or doubling medication doses will be safe and helpful in decreasing the future risk of fractures.
4. Even if bone density deteriorates during treatment, it is quite likely that the patient would have lost even more bone density without treatment.
5. Recent research has shown that women who lose bone density after the first year of HRT will gain bone density in the next 2 years of therapy, whereas women who gain in the first year will tend to lose density in the next 2 years of therapy. Therefore, bone density during treatment fluctuates naturally, and these fluctuations may not correlate with the prevention of fractures due to the medication.

For all of these reasons, as surprising as it may sound to many people (and even some doctors!), rechecking bone density is not at all like checkingblood pressureduring treatment ofhigh blood pressure(hypertension). Routine bone density testing during treatment may not be helpful. In the future, however, if ongoing research brings new technology or new therapies, testing decisions may change.

Currently, the most effective medications for osteoporosis that are approved by the FDA are antiresorptive agents, which decrease the removal of calcium from bones. The bone is a living dynamic structure; it is constantly being built and removed (resorbed). This process is an essential part of maintaining the normal calcium level in the blood and serves to repair tiny cracks in the bones that occur with normal daily activity and remodel bone based on the physical stresses placed on the bone. Osteoporosis results when the rate of bone resorption exceeds the rate of bone rebuilding. Antiresorptive medications inhibit the removal of bone (resorption), thus tipping the balance in favor of bone rebuilding and increasing bone density. HRT is one example of an antiresorptive agent. Others include alendronate (Fosamax), risedronate (Actonel), raloxifene (Evista), ibandronate (Boniva), calcitonin (Calcimar), zoledronate (Reclast), and denosumab (Prolia).

Bisphosphonates

磷酸盐治疗髋部骨折的风险,减少wrist fracture, and spine fracture in people with osteoporosis and can improve the T-score. Alendronate (Fosamax), risedronate (Actonel,Atelvia), ibandronate (Boniva), and zoledronate (Reclast) are bisphosphonates.

To reduce side effects and to enhance absorption of the medicine, all bisphosphonates taken by mouth (orally) should be taken in the morning, on an empty stomach, 30 minutes before breakfast, and with at least 8 ounces (240 ml) of water (not juice). This improves the absorption of the bisphosphonate. Takingthe pillsitting or standing (as well as drinking adequate amounts of liquids) minimizes the chances ofthe pillbeing lodged in the esophagus, where it can cause ulceration and scarring. Patients should also remain upright for at least 30 minutes after taking the pill to avoid reflux of the pill into the esophagus. Newer intravenous bisphosphonates, such as ibandronate (Boniva) and zoledronate (Reclast), bypass the potential esophagus and stomach problems.

Food, calcium,iron supplements,vitaminswith矿物质, or antacids containing calcium, magnesium, or aluminum can reduce the absorption of oral bisphosphonates, thereby resulting in loss of effectiveness. Therefore, oral bisphosphonates should be taken with plain water only in the morning before breakfast. Also, no food or drink should be taken for at least 30 minutes afterward.

Alendronate (Fosamax)

Alendronate (Fosamax) is a bisphosphonate antiresorptive medication. Alendronate is approved for the prevention and treatment of postmenopausal osteoporosis as well as for osteoporosis that is caused by cortisone-related medications (glucocorticoid-induced osteoporosis). Alendronate has been shown to increase bone density and reduce fractures in the spine, hips, and arms. Fosamax is taken by mouth once a week to prevent and treat postmenopausal osteoporosis. Alendronate is the first osteoporosis medication also approved for increasing bone density in men with osteoporosis, either in a daily or a weekly dosing schedule.

Fosamax generally is well tolerated with few side effects. One side effect of alendronate is irritation of the esophagus (the food pipe connecting the mouth to the stomach). Inflammation of the esophagus (esophagitis) and ulcers of the esophagus have been reported infrequently with alendronate use.

Risedronate (Actonel)

Risedronate (Actonel, Atelvia) is another bisphosphonate antiresorptive medication. Like alendronate, this drug is approved for the prevention and treatment of postmenopausal osteoporosis as well as for osteoporosis that is caused by cortisone-related medications (glucocorticoid-induced osteoporosis). Risedronate is chemically different from alendronate and has less likelihood of causing esophageal irritation. Risedronate also is more potent in preventing the resorption of bone than alendronate.

Ibandronate (Boniva)

Ibandronate (Boniva) is a bisphosphonate for the prevention and treatment of postmenopausal osteoporosis. It is available in formulations for both daily and monthly oral use as well as for intravenous use every three months.

Zoledronate (Reclast)

Zoledronate (Reclast) is a unique intravenous bisphosphonate antiresorptive medication that is given once every year. This formulation seems to have a very good ability to strengthen bones and prevent fractures of both spinal and nonspinal bones. The convenience of once-a-year dosing is obvious. As with all bisphosphonates, patients taking Reclast must be taking adequate calcium andvitamin Dprior to and after infusion of the medication for optimal results. Generally, patients are givenacetaminophen(Tylenol) the day of the infusion and for several days afterward to prevent occasional minor muscle and joint aches. The infusion lasts approximately 20-30 minutes. Reclast is used to treat and prevent osteoporosis in postmenopausal women and increases bone mass in men with osteoporosis. Reclast is also used to treat and prevent steroid-induced osteoporosis (glucocorticoid-induced osteoporosis). Reclast reduces the risk of fractures after a low-trauma hip fracture. Reclast should not be used in patients who have hadavascular necrosisor during/prior topregnancy.

Selective estrogen receptor modulators (SERMs)

Raloxifene (Evista)

Raloxifene (Evista) belongs to a class ofdrugscalled selective estrogen receptor modulators (SERMs). SERMs work like estrogen in some tissues but as an antiestrogen in other tissues. The SERMs were developed to reap the benefits of estrogen while avoiding the potential side effects of estrogen. Thus, raloxifene can act like estrogen on the bone but as an antiestrogen on the lining of the uterus where the effects of estrogen can promotecancer.

The first SERM to reach the market wastamoxifen(Nolvadex), which blocks the stimulative effect of estrogen on breast tissue. Tamoxifen has proven valuable in women who have hadcancerin one breast for preventing cancer in the second breast. Raloxifene is the second SERM to be approved by the FDA. Evista has been approved for the prevention and treatment of osteoporosis in postmenopausal women. In a 3-year study involving some 600 postmenopausal women, raloxifene was found to increase bone density (and lowerLDL cholesterol) while having no detrimental effect on the uterine lining (which means that it is unlikely to cause uterine cancer).

Because of its antiestrogen effects, the most common side effects with Evista are hot flashes. Conversely, because of its estrogenic effects, Evista increases the risk of blood clots, includingdeep vein thrombosis(DVT) andpulmonary embolism(blood clots in the lung). The greatest increase in risk occurs during the first four months of use. Patients taking raloxifene should avoid prolonged periods of immobility during travel when blood clots are more prone to occur. The risk ofdeep vein thrombosiswith raloxifene is probably comparable to that of estrogen, about two to three times higher than the usual low rate of occurrence. Evista decreases the risk of spinal fractures in postmenopausal women with osteoporosis, but it is not known if there is a similar benefit in decreasing the risk of hip fracture. (The only agents that are definitely proven to decrease the risk of hip fracture are bisphosphonates and denosumab.)

Calcitonin (Calcimar, Miacalcin)

Calcitonin (Calcimar, Miacalcin) is a hormone that has been approved by the FDA in the U.S. for treating osteoporosis. Calcitonins come from several animal species, but salmon calcitonin is the one most widely used. Calcitonin can be administered as a shot under the skin (subcutaneously), into the muscle (intramuscularly), or inhaled nasally (intranasally). Intranasal calcitonin is the most convenient of the three methods of administration.

Calcitonin has been shown to prevent bone loss in postmenopausal women. In women with established osteoporosis, calcitonin has been shown to increase bone density and strength in the spine only.

Calcitonin is a weaker antiresorptive medication than bisphosphonates. Calcitonin is not as effective in increasing bone density and strengthening bone as estrogen and other antiresorptive agents, particularly bisphosphonates. In addition, it is not as effective as bisphosphonates in reducing the risk of spinal fractures and has not been proven effective in reducing hip fracture risk. Therefore, calcitonin is not the first choice of treatment in women with established osteoporosis. Nevertheless, calcitonin is a helpful alternative treatment for patients who cannot tolerate other medications.

Common side effects of either injected or nasal spray calcitonin arenauseaand flushing. Patients using Miacalcin Nasal Spray can develop nasal irritation, arunny nose, ornosebleeds. Injectable calcitonin can cause local skin redness at the site of injection, skinrash, and flushing.

Teriparatide (Forteo)

Teriparatide (Forteo) is a synthetic version of the human hormone, parathyroid hormone, which helps to regulate calcium metabolism. Unlike other medications for osteoporosis that reduce the resorption of bone, teriparatide very effectively promotes the growth of new bone. Forteo is self-injected into the skin. Because long-term safety is not yet established, it is only FDA-approved for 24 months of use. It reduces spinal fractures in women with known osteoporosis, but it is not known if there is a similar reduction in the risk for hip fracture. Generally, after a 2-year course of teriparatide, the patient is switched to bisphosphonate therapy to maintain bone density.

Denosumab (Prolia)

The latest treatment approved for osteoporosis is denosumab (Prolia), an injectable antibody that blocks a chemical messenger that plays a role in promoting bone thinning by the bone cells that are responsible for bone resorption. Prolia strengthens bone by increasing its density and reducing fractures. Prolia is administered by twice yearly injections under the skin. Denosumab is used for the treatment of postmenopausal women with osteoporosis at high risk for fracture, defined as a history of osteoporotic fracture, multiple risk factors for fracture, or patients who have failed or are intolerant to other available osteoporosis therapy. Denosumab can cause an increased risk of infections and low blood calcium levels (hypocalcemia).

The long-term use of corticosteroids (such as prednisone, cortisone, andprednisolone) can lead to osteoporosis. Corticosteroids cause decreased calcium absorption from theintestines, increased loss of calcium through the kidneys in urine, and increased calcium loss from the bones. To prevent bone loss while on long-term corticosteroids, patients should

1. have adequate calcium (1,000 mg daily if premenopausal, 1,500 mg daily if postmenopausal) and vitamin D intake (the actual level of Vitamin D can be measured with a simple blood test); however, calcium alone or combined with vitamin D cannot be relied upon to prevent bone loss from corticosteroids unless other prescription medications are added;
2. discuss with their doctor the use of either alendronate, risedronate, and zoledronate, which have been approved for the prevention and treatment ofcorticosteroid-induced osteoporosis;
3. discuss with their doctor about having a DXAbone density scanas well as blood testing for calcium, kidney function, and vitamin D prior to beginning therapy and monitoring for osteoporosis during therapy.

Building strong and healthy bones requires an adequate dietary intake of calcium beginning in childhood and adolescence for both sexes. Most importantly, however, a high dietary calcium intake or takingcalcium supplementsalone is not sufficient in treating osteoporosis and should not be viewed as an alternative to or substituted for more potent prescription medications for osteoporosis. In the first several years after menopause, rapid bone loss may occur even if calciumsupplementsare taken.

The following calcium intake has been recommended by the National Institutes of Health Consensus Conference on Osteoporosis for all people, with or without osteoporosis:

• 800 mg/day for children 1-10 years of age
• 1,000 mg/day for men, premenopausal women, and postmenopausal women also taking estrogen
• 1,200 mg/day for teenagers and young adults 11-24 years of age
• 1,500 mg/day for postmenopausal women not taking estrogen
• 1,200 mg-1,500 mg/day forpregnantand nursing mothers
• The total daily intake of calcium should not exceed 2,000 mg.

Daily calcium intake can be calculated by the following method:

1. Excluding dairy products, the average American diet contains approximately 250 mg of calcium.
2. There is approximately 300 mg of calcium in an 8-ounce glass of milk.
3. There is approximately 450 mg of calcium in 8 ounces of plain yogurt.
4. There is approximately 130 mg of calcium in 1 cup of cottage cheese.
5. There is approximately 200 mg of calcium in 1 ounce of cheddar cheese.
6. There is approximately 90 mg of calcium in ½ cup of vanilla ice cream.
7. There is approximately 300 mg of calcium in 8 ounces of calcium-fortified orange juice.

Unfortunately, surveys have shown that the average woman in the U.S. is consuming less than 500 mg of calcium per day in their diet, less than the recommended amounts. Additional calcium can be obtained by drinking more milk and eating more yogurt or cottage cheese or by taking calcium supplement tablets as well from calcium-fortified foods, such as orange juice.

The various calciumsupplementscontain different amounts of elemental calcium (the actual amount of calcium in the supplement). For example,Caltrate,Os-Cal, andTumsarecalcium carbonatesalts. Each 1,250 mg of calcium carbonate salt tablet (such as Caltrate 600 mg,Os-Cal 500mg, or Tums 500 mg extra strength) contains 500 mg of elemental calcium. A person who needs 1,000 mg/day of calcium supplement can take one tablet of Tums 500 mg extra strength (containing 500 mg of elemental calcium) twice daily with meals.

The calcium carbonate supplements are best taken in small divided doses with meals since the intestines may not be able to reliably absorb more than 500 mg of calcium all at once. Therefore, the best way to take 1,000 mg of a calcium supplement is to divide it into two doses. Likewise, a dosage of 1,500 mg should be split into three doses.

钙补充剂是安全的,一般好lerated. Side effects areindigestionandconstipation. Ifconstipationandindigestionoccur with calcium carbonate supplements, calcium citrate (Citracal) can be used. Some patients havedifficulty swallowingcalcium tablets. In this situation, chewable candy-like calcium in the form of Viactiv is available. Certain medications can interfere with the absorption of calcium carbonate. Examples of such medications include proton-pump inhibitors such asomeprazole(Prilosec),lansoprazole(Prevacid), lansoprazole (Protonix), andrabeprazole(Aciphex), which are used in treatinggastroesophageal reflux disease(GERD) or peptic ulcers. When these medications are being taken, calcium citrate is preferred.

Many "natural" calcium carbonate preparations, such as oyster shells or bone meal, may contain high levels of lead or other harmful elements and should be avoided.

An adequate intake of calcium and vitamin D are important foundations for maintaining bone density and strength. However, calcium and vitamin D alone are not sufficient to treat osteoporosis and should be given in conjunction with other treatments. Vitamin D is important in several respects:

• Vitamin D helps the absorption of dietary calcium from the intestines.
• The lack of vitamin D alone can cause calcium-depleted bone (osteomalacia), which further weakens the bones and increases the risk of fractures.
• Vitamin D, along with adequate calcium (1,200 mg of elemental calcium), has been shown in some studies to increase bone density and decrease fractures in postmenopausal women but not in premenopausal or perimenopausal women.

Vitamin D comes from the diet and the skin. Vitamin D production by the skin is dependent on exposure to sunlight. Active people living in sunny regions (Southern California, Hawaii, countries around the equator, etc.) can produce most of the vitamin D they need in their skin. Conversely, lack of exposure to sunlight, due to residence in northern latitudes or physical incapacitation, causesvitamin D deficiency. In less temperate regions such as Minnesota, Michigan, and New York, production of vitamin D by the skin is markedly diminished in the winter months, especially among the elderly. In that population, dietary vitamin D becomes more important.

Unfortunately,vitamin D deficiencyis quite common in the U.S. In a study in a general medical ward of one hospital, vitamin D deficiency was detected in 57% of the patients. An estimated 50% of elderly women consume far less vitamin D in their diet than is recommended. The vitamin D status is easily evaluated with a simple blood test.

The Food andNutritionBoard of the Institute of Medicine has recommended the following as an adequate vitamin D intake:

• 800 IU/day for men and women over the age of 71
• 600 IU/day for women in other age groups, men, and children
• 400 IU/day for infants under 12 months

But if a person already has osteoporosis, it is advisable to ensure 400 IU twice per day as the usual daily intake, most commonly as a supplement alongside prescribed medications for osteoporosis.

An average multivitamin tablet contains 400 IU of vitamin D. Therefore, one to twomultivitaminsa day should provide the recommended amount of vitamin D. Alternatively, vitamin D can be obtained in combination with calcium in tablet forms, such as Caltrate 600 + D (600 mg of calcium and 200 IU of vitamin D) and others.

Adequate levels of calcium and vitamin D are essential for optimal bone health, especially when used with prescribed medication for osteoporosis. Chronic excessive use of vitamin D can lead to toxic levels of vitamin D,elevated calcium levelsin blood and urine, and may also causekidney stones. Since variousdietary supplementsmay also contain vitamin D, it is important to review vitamin D content in dietary supplements before taking additional vitamin D.

Eating a diet that has adequate calcium and vitamin D can be beneficial in preventing osteoporosis.

Are there foods to avoid when it comes to osteoporosis?

Excessive alcohol should be avoided by those with osteoporosis. For those with underlyingceliac disease, it is essential to avoid foods with谷蛋白(wheat, barley, and rye) in them.

Exercise has a wide variety of beneficial health effects. However, exercise does not bring about substantial increases in bone density. The benefit of exercise for osteoporosis has mostly to do with decreasing the risk of falls, probably because balance is improved and/or muscle strength is increased. Research has not yet determined what type of exercise is best for osteoporosis or for how long it should be continued. Until research has answered these questions, most doctors recommend weight-bearing exercise, such as walking, preferably daily for optimal health.

A word of caution about exercise: It is important to avoid exercises that can injure already weakened bones. In patients over 40 and those withheart disease,obesity,diabetes mellitus, andhigh blood pressure, exercise should be prescribed and monitored by physicians. Extreme levels of exercise (such as marathonrunning) may not be healthy for the bones. Marathon running in young women that leads toweight lossand loss of menstrual periods can actually promote osteoporosis.

Smokingone pack of cigarettes per day throughout adult life can itself lead to a loss of 5%-10% of bone mass.Smokingcigarettes decreases estrogen levels and can lead to bone loss in women before menopause. Smoking cigarettes also can lead to earlier menopause. In postmenopausal women, smoking is linked with an increased risk of osteoporosis. Data on the effect of regular consumption of alcohol andcaffeineon osteoporosis is not as clear as with exercise and cigarettes. In fact, research regarding alcohol andcaffeineas risk factors for osteoporosis shows widely varying results and is controversial. Certainly, their effects are not as great as other factors. Nevertheless, moderation of both alcohol and caffeine is prudent.

Elderly people with osteoporosis can decrease their risk for hip fracture by maintaining muscle strength, coordination, and balance with exercise programs. Throw rugs and animals in pathways of the home should be minimized or eliminated. Good lighting is essential for safe walking to the restroom both day and night.

Additionally, for those elderly people who use canes for walking, etc., it is essential that the rubber tips of the canes are regularly checked for any signs of wear. When this rubber wears through it presents a serious risk of causing the cane (and, therefore, the person) to slip, which can result in serious bodily harm -- includinghip fracture.

Controversy

Currently, it is not clear how long patients with osteoporosis are treated with bisphosphonates and should continue the bisphosphonate treatment. Many doctors are interrupting treatment for a "drug holiday" off of the drug as it may not be necessary after 5-7 years. Guidelines for the duration of treatment of osteoporosis with bisphosphonates are being developed.

The primary complication of osteoporosis is a bone fracture.

• This may lead to no symptoms or be associated with severe, intractable pain.
• Recurrent fractures are common and can lead to deteriorating skeletal structure.
• Occasionally, fractures of the spinal vertebrae can push bone into adjacent nerves and/or the spinal cord.
• This can require neurosurgical intervention.
• Osteoporotic vertebral fractures can also be relieved by vertebroplasty (kyphoplasty) procedures whereby the collapsed vertebra is inflated by a balloon and a cement (methylmethacrylate) is injected to reform the structure of the vertebra.

Repeated vertebral compression fractures can lead to severe deformity of the spine of the chest (kyphosis) that can compromise breathing along with cause extreme loss of height. This can increase the risk of problems with any respiratory infections.

The outlook for patients with osteoporosis depends greatly on where fractures occur. Additionally, if treatment is begun when the bone disease is detected early, the outcome is better.

Hip fractures are a particularly dangerous consequence of osteoporosis in the elderly. Approximately 20% of those who experience a hip fracture will die in the year following the fracture. Only one-third of hip-fracture patients regain their pre-fracture level of function. One-third of hip-fracture patients are discharged to a nursing home within the year after fracture.

Newer medications, medicine with different methods of delivery, and research into the optimal management of osteoporosis will bring even better options for the healthcare of patients with osteoporosis in the future. Persons interested in more information about osteoporosis and its treatment options can get information from the National Osteoporosis Foundation.