Osteoporosis

Weak bones effect an estimated 44 million Americans, which is greater than 50% of those over 50. Ten million American over the age of 50 are afflicted with osteoporosis while approximately 34 million more are estimated to have low bone mass, know as osteopenia, placing them at increased risk for osteoporosis (National Osteoporosis Foundation, 2007). Osteoporosis is expensive, costing the health care system 17 billion dollars a year.

Osteoporosis is a skeletal disorder characterized by reduced bone strength secondary to reduced quantity and quality of the bone. When fractures occur the body is set up for many of the complication of osteoporosis, such as extended or permanent immobility, increased risk of developing several diseases and increased risk of death.

Osteoporosis is responsible for more than 1.5 million fractures each year with women being affected much more than men. Almost one-half of postmenopausal women will suffer an osteoporosis-related fracture in their life. Fracture, most commonly in the hip, spine and wrist, is a top cause of nursing home placement and permanent disability. After a fracture many patients are unable to walk without the aid of a cane. This reduction in mobility sets the body up for many diseases associated with inactivity such as diabetes, heart disease and stroke.

Vertebral fractures are associated with their own set of complications including chronic back pain, kyhosis, height loss and death. Lumbar fractures increase the risk of constipation, weight loss and abdominal pain. Thoracic fractures can lead to restrictive lung disease.

Osteoporosis, characterized by thin, less dense bones, is often called the "silent disease" because it occurs without symptoms. People may not know that they have osteoporosis until their bones are so fragile that a minor stress or fall causes a hip to fracture or a vertebra to collapse.

Bone mass, which peaks between the ages of 25-30, can vary depending on many factors. Through out life the body removes older bone and replaces it with new bone. When bone loss is greater than replacement than bone mass dwindles.

Osteoporosis occurs when the bones experience accelerated bone loss in older age (typically during the sixth decade), often in combination with reduced bone mass acquisition during the adolescence. It typically results from a combination of hormone imbalance, genetics, decreased physical activity, poor nutrition, medications, and other medical co-morbidities.

Osteoporosis is characterized by increased bone turn over which leads to reduced bone quality. This reduced bone quality is because of decreased bone mass, disrupted trabecular connectivity, decreased mineralization, and increased cortical porosity.

Several factors put people at risk for osteoporosis. Nurses need to identify those at risk for osteoporosis so they can encourage a lifestyle that is consistent with positive bone health. Important risk factors include being of low body weight, older age, female sex and having no estrogen. See the list below for other risk factors associated with osteoporosis.

Despite its high prevalence, there are few symptoms that define the disease. Broken bones, most commonly the hip, forearm or vertebrae are commonly the first presentation of the disease. Loss of height with a hunched over stance, due to thinning of the vertebrae, is another presentation of osteoporosis. Women can lose up to 20 percent of their bone mass in the five to seven years following menopause, making them more susceptible to osteoporosis.

The history and physical exam cannot diagnose the disease but it does give clues to risk for the disease and the potential of a secondary cause of osteoporosis. History should elicit any risk factors noted above. Other salient features of a nursing history should include a nutritional screen, exercise and family history, and medical history specifically looking for a history of fractures. Review the medications for any medications known to reduce bone mass. Any complaint of upper or middle back pain or loss of height may suggest a compression fracture. Presentation typically includes back pain that is made worse by movement with occasional radiation into the stomach.

The physical exam should attempt to determine if osteoporosis is present and elicit any secondary causes. No physical exam finding can accurately diagnose the disease but a dowager’s hump in the older patient indicates reduced bone volume and multiple vertebral fractures. Cushing syndrome and hyperthyroidism can be identified during physical exam. Cushing syndrome is indicated by a moon face, buffalo hump, and thin skin, hyperthyroidism is indicated by enlarged thyroid and lid lag.

Determining if the disease is primary or secondary will help assure the disease is treated properly. Primary osteoporosis is not related to another disease process and associated with age and a change in the hormonal balance. Those afflicted with early menopause, poor calcium or vitamin D intake, tobacco and alcohol use, sedentary lifestyle or premenopausal estrogen deficiency are at high risk for early onset primary osteoporosis.

Secondary osteoporosis is related to another chronic condition. Physical exam and laboratory analysis is used to look for signs of secondary osteoporosis. Disease processes such as hyperthyroidism, hyperparathyroidism, hypogonadism, Cushing syndrome, vitamin D deficiency, multiple myeloma, hemochromatosis, pituitary tumor or acromegaly can lead to secondary osteoporosis.

Medications including: excessive thyroid replacement, methotrexate, phenobarbital, phenytonin, long-term heparin, and proton pump inhibitors can lead to osteoporosis. Nutritional conditions such as alcohol abuse, calcium and vitamin D deficiency and malabsorptive syndromes are associated with secondary osteoporosis.

Labs can help detect secondary causes of osteoporosis when an overt sign is found on exam or the clinical picture does not make primary osteoporosis a likely diagnosis. Routine workup for secondary causes should include including a blood count, blood chemistries including calcium, kidney and liver function, TSH for thyroid status, and 25-hydroxy vitamin D. Some patients may be candidates for a 24-hour urine calcium, parathyroid level, serum iron and ferritin, 24-hour urine free cortisol, overnight dexamethasone suppression test, ESR, protein electrophoresis, and men should get a testosterone level.

The gold standard in the detection of osteoporosis is the Duel-energy x-ray absorptiometry (DEXA) scan which measures bone mineral density. Plain radiographs do not detect osteoporosis until bone density is significantly decreased. Quantitative computerized tomography is the most sensitive method for testing bone density but results in high amount radiation exposure so a DEXA scan is the diagnostic tool of choice.

Systems to assess the peripheral skeleton are used, but their predictive value is less clear. These look at the forearm, middle phalanx and heel. If this method is used than any follow up scans should be obtained on the same machine.

All women above age 65, even without other risk factors should have a DEXA scan. In addition, women after menopause with other risk factors should be tested. A fracture in a postmenopausal woman is enough to diagnosis osteoporosis, but they should have a DEXA scan to quantify how severe the disease is. Men are tested less frequently. If there is a history of previous fracture, he is taking one of the risk medications, or has a strong family history of male osteoporosis than screening should ensue. Routine screening for men is not recommended.

The DEXA scan, which takes 10-20 minutes, is an x-ray that evaluates the density of bones. The test gives a reading in the form of a T-score, which compares bone density to a 25-30 year-old. A score is reported, with an average bone density of 0, which is indicative of a normal bone density of a 25-30 year old. If the score is above 0 then the individual has a higher bone density than the average 25-30 year old. If the score is below 0 than the bone density is less. Scores between -1.0 and -2.4 are classified as having osteopenia. Osteopenia is defined as bones that are thinner than average but not pathologically so. Individual who have T-scores less than or equal to -2.5 are classified as having osteoporosis.

A Z-score is sometimes used which compares the patient to someone with the same age, sex and race. While this method seems theoretically good, it is not useful to the practicing clinician as treatment guidelines are based on the T-score.

Prevention is a vital step in reducing the complications of osteoporosis. Nurses have a key role in the teaching and encouraging patients to prevent osteoporosis. All persons should be educated about the risk factors of osteoporosis and what can be done to prevent it.

Exercise has many benefits but prevention of osteoporosis is one of the more important benefits. Weight bearing exercise, for example walking, is the best for improving bone strength. Weight bearing exercise has been shown to be more effective than non-weight bearing exercise in the treatment and prevention of osteoporosis. Non-weight bearing exercises include biking and swimming. In addition to aerobic exercise, weight training is an essential part of osteoporosis prevention. Upper body weight training builds the strength of the bones in the upper body.

Diet can have a profound impact on the skeletal system. Eating a diet high in calcium and vitamin D or supplement with these nutrients is essential in preventing osteoporosis (see table 3). Most American diets are not high enough in calcium and vitamin D; supplementation is often required. Sensible sun exposure, about 10 minutes of exposure of the hands, arms, and face, three to four times per week, and increased dietary and/or supplemental vitamin D intakes should prevent vitamin D deficiency. Obtaining at least 1200 mg of calcium and 400-800 IU of vitamin D is the recommended. Those who do not obtain this level should consider supplementation.

By about age 20, the average woman has acquired most of her skeletal mass. Building strong bones during childhood and adolescence can be the best defense against developing osteoporosis later.

These are five steps, which together, can optimize bone health and help prevent osteoporosis.

• A balanced diet rich in calcium and vitamin D
• Weight-bearing exercise and weight training
• No smoking or excessive alcohol intake
• Talking to your healthcare professional about bone health
• Bone density testing and medication when appropriate

Many of the same interventions for the prevention of osteoporosis apply to its treatment. When the diagnosis of osteoporosis is given the nurse needs to continue to teach about the importance of exercise, nutrition, and limiting alcohol and smoking. In addition, medications are typically implemented after osteoporosis is diagnosed.

Goals of treatment ultimately involve reducing fracture rates. Many of the studies look at increased bone mass as an outcome of the intervention, but the most important factor when evaluating treatment options are their ability to reduce fracture rates, as fractures cause the majority of complications in osteoporosis.

Who is a candidate for treatment? Everyone is a candidate for preventative measures, but certain groups should be treated pharmacologically. These include preventative treatment of those with a T-score between -2.0 and -2.5 with one of the following risk factors: weight less than 127 pounds, history of a hip fracture in parent or personal history of fracture. In addition, anyone with a T-score below 2.5 is a candidate for treatment.

Nursing provides a critical role in the prevention and treatment of osteoporosis. A main predictor of fracture in older patients is compliance with medication. Nurses need to encourage patients to comply with medication and help patients to develop strategies to reduce non-compliance. Some osteoporosis medications are given once a week or even once a month, therefore special reminders need to be implemented to assure compliance. Another role of nursing is to counsel patients about getting bone mineral density testing and promoting healthy lifestyles. The introduction of an osteoporosis case manager improves quality of care for the older patient at high risk for fracture who lives in the community (Sumit R, et al., 2007).

Patients with osteoporosis should take at least 1,200 mg of calcium daily and 400-800 units (some experts recommend up to 1,000 units) of vitamin D. When monitoring levels of vitamin D, maintain a level of 25-hydroxy vitamin D of at least 30 mg/ml.

If a vitamin D deficiency is found then 50,000 units of vitamin D once a week for 8 to 12 doses should be implemented. Once levels stabilize, patients should take 1,000 units daily or 50,000 units once or twice a month.

Bisphosphonates are Alendronate (Fosamax); Risedronate, (Actonel); Ibandronate (Boniva®). Bisphosphonates are the most popular drugs prescribed for the treatment of osteoporosis. In 2003, bisphosphonates were the most common treatment in osteoporosis therapy and were prescribed in 73% of patient visits (Stafford et al., 2005). They are indicated for osteoporosis in men and women as well glucocorticoid-induced osteoporosis. Bisphosphonates increase bone mineral density and inhibit bone resorption. They are believed to alter function and activate osteoclasts. This class of drugs has proven efficacy at reducing the rate of fracture from 36-50% over three years (National Osteoporosis Foundation, 2003). Bisphosphonates are formulated so they can be taken once a day, once a week or even once a month (Ibandronate).

Bisphosphonates should be taken in the morning, on an empty stomach and the patient should not lie down or eat for 30 minutes after taking the medicine. Ibandronate should be taken 60 minutes before food and patients should remain upright for 60 minutes after taking it. It should also be taken with a full glass of water.

One major side effect is irritation of the gastrointestinal tract. It can lead to inflammation of the esophagus, gastric ulcer or dysphagia. One rare complication is osteonecrosis of the jaw if given intravenously. Patients with significant kidney dysfunction should not use this drug.

Calcitonin (Miacalcin) decreases the amount of bone being broken down. This drug is given as an injection or a nasal spray and works by inhibiting osteoclast activity; therefore, slowing bone loss. Calcitonin is not as effective as Bisphosphonates, but is often used by those who cannot use Bisphosphonates. Calcitonin is indicated for women at least five years postmenopausal. It provides an analgesic effect and can be helpful in those with fractures due to osteoporosis. Side effects of this drug include nausea, flushing, diarrhea and nasal irritation. It reduced the risk of recurrent vertebral fracture by 33%, but does not affect non-vertebral or hip fractures.

Estrogen can be used to treat osteoporosis but has lost some favor over the last few years because there is an increased risk of complications: heart attack, stroke, invasive breast cancer, pulmonary embolism, and deep vein thrombosis. Roloxifene increases the risk of fatal stroke, increases the risk of blood clots and increases hot flashes. Even though data shows that Estrogen reduces hip and spinal fracture rates, it is not recommended for use because other agents are at least equal in effectiveness and lower risk.

The Selective Estrogen Receptor Modulators (SERMs), Raloxifene (Evista), is used to treat osteoporosis. It improves bone density but has not proven to be the best treatment option for fracture prevention. Over a three year period in patients with prior vertebral fractures, it decreased the risk of new vertebral fractures by 30%. For people with osteoporosis and no history of fracture, the risk of vertebral fractures was reduced by 55% (National Osteoporosis Foundation, 2003). No effect seen on the reduction of non-vertebral or hip fractures.

Parathyroid hormone, Teriparatide (Fortéo), is a bone building drug. It increases bone turnover with bone formation exceeding bone resorption leading to an increase in bone mass and an improvement in the bone architecture. It is given by subcutaneous injection one time a day and is an expensive option to treat osteoporosis. It promotes new bone formation by regulating calcium and phosphate metabolism. For people with baseline vertebral fractures there is a decreased risk of recurrent vertebral fractures by 65% and decreased risk of non-vertebral fragility fractures by 53%, compared with placebos (National Osteoporosis Foundation, 2003). Parathyroid hormone is approved for the treatment of osteoporosis in post-menopausal women and men who are at high risk of fracture with osteoporosis. This medication can only be given for 24 months. The addition of bisphosphonates may be used after the 24 months to protect the bone.

Contraindications for this drug include Paget’s disease, unexplained increases in alkaline phosphatase, hypercalcemia, hyperparathyroidism, history of external beam radiation, or prior radiation to the skeleton. Side effects include hypercalcemia, nausea, leg cramps, and dizziness.

In men with testosterone deficiency the use of androgens is appropriate. Testosterone injection is indicated for low bone mineral density with hypogonadism. It is given as in intrasumuscular injection every two to four weeks. This may increase the risk of prostatic hyperplasia and prostate cancer and it should not be used in those with prostate or breast cancer. Testosterone can also be given as a topical treatment as a dose of 5 to 7.5 mg per day.

Combining treatments is no more effective than monotherapy in respect to a reduction in the number of fractures. Some evidence suggests that the combination of estrogen or raloxifine with other treatment options may increase bone density a small amount, but it did not translate into a reduction of fracture rate.

Osteoporosis is a chronic disease that needs continued attention. Follow up analysis of bone mineral density should occur every one to two years when starting therapy and than every two years. Payment through Medicare will only occur every two years. For those who have an initial normal exam, a follow up exam may ensue every 3-5 years or not at all if bone density is well above normal.

The goal is stable or improved bone mineral density. If bone mass decreases there may be several causes: inaccurate testing, noncompliance with medication, secondary causes that are untreated, or the patient is a non-responder to medication.

Osteoporosis is a serious and prevalent disease. Early identification of people at risk for osteoporosis should be done. Screening with DEXA scans for people who qualify will increase the identification of osteoporosis and allow earlier initiation of treatment. This should result in a reduction in the numbers of fractures and complications. The nurse’s main function is to educate patients and help them live a lifestyle consistent with good bone health. Lastly, helping the patient communicate effectively with their health care provider will assure proper medical management (Table 4).

National Osteoporosis Foundation. Fast facts. Retrieved December 14, 2007 from http://www.nof.org/osteoporosis/diseasefacts.html.

Eskandari, F, Martinez, P. E, Torvik, S, et al. (2007). Low bone mass in premenopausal women with depression. Achieves of Internal Medicine. 167(21), 2329-36.

Zhang, X, Shu, X, Li, H, et al. (2005). Prospective Cohort Study of Soy Food Consumption and Risk of Bone Fracture Among Postmenopausal Women. Achieves of Internal Medicine. 165, 1890-1895.

Sumit, M. R, Beaupre, L. A, Harley, C. H. et al. (2007) Use of a Case Manager to Improve Osteoporosis Treatment after Hip Fracture: Results of a Randomized Controlled Trial. Achieves of Internal Medicine. 167(19), 2110-2115.

Stafford, R. S, Drieling, B. A, Hersh, A. L. (2004). National Trends in Osteoporosis Visits and Osteoporosis Treatment, 1988-2003. Archeives of Internal Medicine. 164, 1525-1530.

National Osteoporosis Foundation. Physicians Guide to the Prevention and Treatment of Osteoporosis. Retrieved December 14, 2007 from http://www.nof.org/physguide/inside_cover.htm.