Osteoporosis

Osteoporosis :

      Osteoporosis is a condition in which the bones are weakened due to a decrease in the bone mass that makes up the skeleton. Due to Osteoporosis bones become fragile and more likely to fracture. Usually the bone loses density, which measures the amount of calcium and minerals in the bone.

      Throughout life, bones are continuously remodeled. While a child is growing, the rate of bone formation is greater than the rate of bone breakdown. The skeletal mass continues to increase until ages 20 to 30. After that, the rates of formation and breakdown of bone mass are equal until ages 40 to 50. Then, re-absorption begins to exceed formation, and the total bone mass slowly decreases.

Causes, incidence, and risk factors: 

      Osteoporosis is the most common type of bone disease. Because of osteoporosis about half of all women over the age of 50 will have a fracture of the hip, wrist, or vertebra (bone of the spine) during their lifetime. Bone is living tissue. Existing bone is constantly being replaced by new bone. Osteoporosis occurs when the body fails to form enough new bone, when too much existing bone is reabsorbed by the body, or both. Calcium is one of the important minerals needed for bones to form. If you do not get enough calcium and vitamin D, or your body does not absorb enough calcium from your diet, your bones may become brittle and more likely to fracture. Sometimes bone loss occurs without any cause.  Sometimes the tendency to have bone loss and thin bones is passed down through families. 

      A drop in estrogen in women at the time of menopause and a drop in testosterone in men is a leading cause of bone loss. Over time, men are apt to lose 25% and women 35% of their bone mass. But we have to consider that men tend to have denser bones than women anyway, and their testosterone (male sex hormone) level generally does not begin to decline significantly until after age 65. In contrast, the estrogen (female sex hormone) level in women begins to decline at about age 45. Because sex hormones play an important role in maintaining bone strength, this difference means that women are more likely than men to suffer fractures, involving especially the hip, vertebrae, long bones, and pelvis. Although osteoporosis may at times be the result of various disease processes, it is essentially a disease of aging.
     

Other risk factors include: 

• Absence of menstrual periods (amenorrhea) for long periods of time. 
• A family history of osteoporosis. 
• Drinking a large amount of alcohol.
• Low body weight.
• Smoking.

 Symptoms:

      There are no symptoms in the early stages of osteoporosis. Many times, people will have a fracture before learning that they have the disease. Pain almost anywhere in the spine can be caused by fractures of the bones of the spine. These are called compression fractures. They often occur without an injury. The pain occurs suddenly or slowly over time. There can be a loss of height (as much as 6 inches) over time. A stooped posture or kyphosis (also called a dowager's hump) may develop. 

Diagnosis:

      Baseline laboratory studies include the following: 

• Complete blood count: May reveal anemia or raise suspicion of alcoholism. 
• Serum chemistry levels: Usually normal in persons with primary osteoporosis. • Serum iron and ferritin levels: Helpful when malabsorption or hemochromatosis is suspected. 
• Liver function tests: Elevations may indicate alcoholism.
• Thyroid-stimulating hormone level: Thyroid dysfunction has been associated with osteoporosis.
• 25-Hydroxy vitamin D level: Vitamin D insufficiency can predispose to osteoporosis. 

      Bone mineral density (BMD) measurement: It is recommended in the following patients: 

• Women aged 65 years or older and men aged 70 years or older, regardless of clinical risk factors.
• Younger postmenopausal women and men aged 50-70 years with clinical risk factors for fracture.
• Women in menopausal transition with a specific risk factor associated with increased risk for fracture (ie, low body weight, prior low-trauma fracture, use of a high-risk medication).
• Adults with fragility fractures.
• Adults who have a condition associated with low bone mass or bone loss (eg, rheumatoid arthritis)/
• Adults who take a medication associated with low bone mass or bone loss (eg, glucocorticoids, ≥5 mg of prednisone daily for ≥3 mo).
• Anyone being considered for pharmacologic therapy for osteoporosis.
• Anyone being treated for osteoporosis (to monitor treatment effect).

      Dual-energy x-ray absorptiometry (DXA): 

      It is currently the criterion standard for the evaluation of BMD. Peripheral DXA is used to measure BMD at the wrist; it may be most useful in identifying patients at very low fracture risk who require no further workup. DXA provides the patient’s T-score, which is the BMD value compared with that of control subjects who are at their peak BMD. 

      World Health Organization (WHO) criteria define a normal T-score value as within 1 standard deviation (SD) of the mean BMD value in a healthy young adult. Values lying farther from the mean are stratified as follows: 

• T-score of –1 to –2.5 SD indicates osteopenia.
• T-score of less than –2.5 SD indicates osteoporosis.
• T-score of less than –2.5 SD with fragility fracture(s) indicates severe osteoporosis.

      DXA also provides the patient’s Z-score, which reflects a value compared with that of persons matched for age and sex. Z-scores adjusted for ethnicity or race should be used in the following patients:

• Premenopausal women. 
• Men younger than 50 years. 
• Children.

      Z-score values of –2.0 SD or lower are defined as "below the expected range for age" and those above –2.0 SD as "within the expected range for age." The diagnosis of osteoporosis in these groups should not be based on densitometric criteria alone.

 

Plain radiography features and recommendations are as follows:

• Obtain radiographs of the affected area in symptomatic patients
• Lateral spine radiography can be performed in asymptomatic patients in whom a vertebral fracture is suspected; a scoliosis series is useful for detecting occult vertebral fractures 
• Radiographic findings can suggest the presence of osteopenia, or bone loss, but cannot be used to diagnose osteoporosis 
• Radiographs may also show other conditions, such as osteoarthritis, disk disease, or spondylolisthesis.

Management:

Treatment for osteoporosis may involve:

• Lifestyle changes, such as diet and exercise.
• Taking calcium and vitamin D 
• Using medicines

Medicines are used to strengthen bones when:

• Osteoporosis has been diagnosed by a bone density study, whether or not you have a fracture.
• A bone fracture has occurred and a bone density test shows that you have thin bones, but not osteoporosis.

Medicines used to treat osteoporosis: 

      The National Osteoporosis Foundation (NOF) recommends that pharmacologic therapy should be reserved for postmenopausal women and men aged 50 years or older who present with the following: 

• A hip or vertebral fracture (vertebral fractures may be clinical or morphometric [ie, identified on a radiograph alone])
• T-score of –2.5 or less at the femoral neck or spine after appropriate evaluation to exclude secondary causes  
• Low bone mass (T-score between –1.0 and –2.5 at the femoral neck or spine) and a 10-year probability of a hip fracture of 3% or greater or a 10-year probability of a major osteoporosis-related fracture of 20% or greater based on the US-adapted World Health Organization algorithm.

      Guidelines from the American Association of Clinical Endocrinologists include the following recommendations for choosing drugs to treat osteoporosis:

• First-line agents: Alendronate, risedronate, zoledronic acid, denosumab
• Second-line agent: Ibandronat.
• Second- or third-line agent: Raloxifene 
• Last-line agent: Calcitonin 
• Treatment for patients with very high fracture risk or in whom bisphosphonate therapy has failed: teriparatide

• Bisphosphonates (the main drugs used to prevent and treat osteoporosis in postmenopausal women)

Exercise plays a key role in preserving bone density : 

      In older adults some of the exercises recommended to reduce the chance of a fracture include:

• Weight-bearing exercises -- walking, jogging, playing tennis, dancing.
• Free weights, weight machines, stretch bands
• Balance exercises -- tai chi, yoga 
• Rowing machines.

     Avoid any exercise that presents a risk of falling. Also, do not do high-impact exercises that can cause fractures in older adults.

     Your body needs calcium and vitamin D to keep your bones strong. Vitamin D helps your body absorb calcium.

• The U.S. National Institutes of Health recommend a calcium intake of 1,200–1,500 mg per day during puberty.
• Adults under age 50 should have 1,000 mg of calcium and 400 - 800 IU of vitamin D daily. 
• Women ages 51 to 70 should have 1,200 mg of calcium and 400 - 800 IU of vitamin D a day; 
• Men ages 51 to 70 need 1,000 mg of calcium and 400 - 800 IU of vitamin D a day. 
• Adults over age 70 should get 1,200 mg of calcium and 800 IU of vitamin D daily.

      Follow a diet that provides the proper amount of calcium and vitamin D.

Stop unhealthy habits:

• Quit smoking, if you smoke.
• Limit your alcohol intake. Too much alcohol can damage your bones. This puts you at risk of falling and breaking a bone.

It is important to prevent falls. The following are suggestions on how to do this:

• Do not take sedating medicines, which can make you drowsy and unsteady. If you must take them, be extra careful when you are up and about. For example, hold on to countertops or sturdy furniture to avoid falling.
• Remove household hazards, such as throw rugs, to reduce the risk of falls. 
• Leave lights on at night so you can see better when walking around your house. 
• Install and use safety grab bars in the bathroom. 
• Make sure your vision is good. Have your eyes checked once or twice a year by an eye doctor. 
• Wear shoes that fit well and that have heels. This includes slippers. Slippers that do not have heels can cause you to trip and fall. 
• Do not walk outdoors alone on icy days.

Prognosis:

      The prognosis for osteoporosis is good if bone loss is detected in the early phases and proper intervention is undertaken. Patients can increase BMD and decrease fracture risk with the appropriate anti-osteoporotic medication. In addition, patients can decrease their risk of falls by participating in a multifaceted approach that includes rehabilitation and environmental modifications. Worsening of medical status can be prevented by providing appropriate pain management and, if indicated, orthotic devices.

      Osteoporosis can cause a person to become disabled from weakened bones. Hip fractures are one of the main reasons people are admitted to nursing homes. Calcium is important for building and maintaining healthy bone. A small daily amount of vitamin D is also necessary to absorb calcium from the digestive tract. Exposure to sunlight is required to allow skin to synthesize vitamin D. Following a healthy, well-balanced diet can help you get these and other important nutrients. Postmenopausal women should have an evaluation of their bone density.