OSTEOPOROSIS



OSTEOPOROSIS

-a condition characterized by decreased bone strength

-defined as a reduction in the strength of bone leading to an increased risk of fractures

-prevalent among postmenopausal women but also occurs in men and women with underlying conditions or major risk factors associated with bone demineralization

-chief clinical manifestations are vertebral and hip fractures, although fractures can occur at any skeletal site

-loss of bone tissue is associated with deterioration in skeletal microarchitecture

EPIDEMIOLOGY

-8 million women and 2 million men have osteoporosis in the United States

-osteoporosis occurs more frequently with increasing age as bone tissue is progressively lost

-in women, the loss of ovarian function at menopause precipitates rapid bone loss such that most women meet the diagnostic criterion for osteoporosis by age 70–80

-epidemiology of fractures follows the trend for bone density loss

-fractures of the distal radius increase in frequency before age 50 and plateau by age 60

-in contrast, incidence rates for hip fractures double every 5 years after age 70

-This distinct epidemiology may be related to the way people fall as they age, with fewer falls on an outstretched hand and more falls directly on the hip

-at least 1.5 million fractures occur each year in the United States as a consequence of osteoporosis

-as the population continues to age, the total number of fractures will continue to escalate.

-about 300,000 hip fractures occur each year in the United States, most of which require hospital admission and surgical intervention

- multiple vertebral fractures lead to height loss (often of several inches), kyphosis, and secondary pain and discomfort related to altered biomechanics of the back

-thoracic fractures can be associated with restrictive lung disease

-lumbar fractures are associated with abdominal symptoms including distention, early satiety, and constipation

-approximately 250,000 wrist fractures occur in the United States each year

-in addition to bone density there are a number of risk factors for fracture:

• Age, prior fractures, a family history of osteoporosis-related fractures, low body weight, cigarette consumption, and excessive alcohol use are each independent predictors of fracture

-chronic diseases with inflammatory components that increase skeletal remodeling:

• such as rheumatoid arthritis, increase the risk of osteoporosis, as do diseases associated with malabsorption

-in the United States and Europe, osteoporosis-related fractures are more common among women than men

-fractures are themselves risk factors for future fractures

-Osteoporotic bone is more likely to fracture than normal bone at any level of trauma

PATHOPHYSIOLOGY

-Osteoporosis results from bone loss due to age-related changes in bone remodeling as well as extrinsic and intrinsic factors that exaggerate this process

-In adults, bone remodeling, and not modeling, is the principal metabolic skeletal process

-Bone remodeling has two primary functions:

• to repair microdamage within the skeleton to maintain skeletal strength,

• to supply calcium from the skeleton to maintain serum calcium

-Remodeling may be activated by microdamage to bone as a result of excessive or accumulated stress

-chronic demands for calcium result in:

• secondary hyperparathyroidism, increased bone remodeling, and overall loss of bone tissue

-additional influences include nutrition (particularly calcium intake) and physical activity level

-after age 30–45, the Resorption and Formation Processes become imbalanced, and resorption exceeds formation

-excessive bone loss can be due to an increase in osteoclastic activity and/or a decrease in osteoblastic activity

-even a slight exaggeration in normal bone loss increases the risk of osteoporosis-related fractures, due to the architectural changes that occur

CALCIUM NUTRITION

-Peak Bone Mass may be impaired by inadequate calcium intake during growth among other nutritional factors thereby leading to increased risk of osteoporosis later in life

-adult phase of life, insufficient calcium intake contributes to relative secondary hyperparathyroidism and an increase in the rate of bone remodeling to maintain normal serum calcium levels

-long-term effects are detrimental to the skeleton because the increased remodeling rates and the ongoing imbalance between resorption and formation at remodeling sites combine to accelerate loss of bone tissue

VITAMIN D

-Vitamin D insufficiency leads to compensatory secondary hyperparathyroidism and is an important risk factor for osteoporosis and fractures

-dark-skinned individuals are also at high risk of vitamin D deficiency

ESTROGEN STATUS

-the most frequent estrogen-deficient state is the cessation of ovarian function at the time of menopause, which occurs on average at the age of 51

-Estrogen may also play an important role in determining the life span of bone cells by controlling the rate of apoptosis

-in situations of estrogen deprivation, the life span of osteoblasts may be decreased, whereas the longevity and activity of osteoclasts are increased

PHYSICAL ACTIVITY

-Inactivity, such as prolonged bed rest or paralysis, results in significant bone loss

-epidemiologic data support the beneficial effects on the skeleton of chronic high levels of physical activity

-when exercise is initiated during adult life, the effects of moderate exercise on the skeleton are modest

CHRONIC DISEASE

-various genetic and acquired diseases are associated with an increase in the risk of osteoporosis

MEDICATIONS

- Glucocorticoids are the most common cause of medication-induced osteoporosis

-Anticonvulsants are thought to increase the risk of osteoporosis

-Aromatase inhibitors, which potently block the aromatase enzyme that converts androgens and other adrenal precursors to estrogen, reduce circulating postmenopausal estrogen levels dramatically

CIGARETTE CONSUMPTION

-the use of cigarettes over a long period has detrimental effects on bone mass

-On average, cigarette smokers reach menopause 1–2 years earlier than the general population

-also produces secondary effects that can modulate skeletal status, including:

• intercurrent respiratory and other illnesses, frailty, decreased exercise, poor nutrition, and the need for additional medications

MEASUREMENT OF BONE MASS

-several noninvasive techniques are now available for estimating skeletal mass or density

• dual-energy x-ray absorptiometry(DXA)

• single-energy x-ray absorptiometry (SXA),

• quantitative CT,

• Ultrasound

- DXA is a highly accurate x-ray technique that has become the standard for measuring bone density in most centers

- CT is different from all others currently available since this technique is three dimensional and can provide a true density (mass of bone tissue per unit volume)

- The Hip is the preferred site of measurement in most individuals, since it predicts the risk of hip fracture, the most important consequence of osteoporosis, better than any other bone density measurement site

WHEN TO MEASURE BONE MASS

-The original National Osteoporosis Foundation guidelines recommend bone mass measurements in postmenopausal women, assuming they have one or more risk factors for osteoporosis in addition to age, gender, and estrogen deficiency

-guidelines further recommend that bone mass measurement be considered in all women by age 65, a position ratified by the U.S. Preventive Health Services Task Force

APPROACH TO THE PATIENT:

Osteoporosis

The perimenopausal transition is a good opportunity to initiate discussion about risk factors for osteoporosis and to consider indications for a BMD test. A careful history and physical examination should be performed to identify risk factors for osteoporosis. For patients who present with fractures, it is important to ensure that the fractures are not caused by an underlying malignancy. Usually this is clear on routine radiography, but on occasion, CT, MRI, or radionuclide scans may be necessary.

ROUTINE LABORATORY EVALUATION

A general evaluation that includes:

• complete blood count, serum and 24-h urine calcium, and renal and hepatic function tests useful for identifying selected secondary causes of low bone mass, particularly for women with fractures or very low Z-scores.

An elevated serum calcium level suggests hyperparathyroidism or malignancy, whereas a reduced serum calcium level may reflect malnutrition and osteomalacia.

Vitamin D levels should be optimized in all individuals being treated for osteoporosis. Hyperthyroidism should be evaluated by measuring thyroid-stimulating hormone (TSH).

When bowel disease, malabsorption, or malnutrition is suspected, serum albumin, cholesterol, and a complete blood count should be checked.

BONE BIOPSY

Tetracycline labeling of the skeleton allows determination of the rate of remodeling as well as evaluation for other metabolic bone diseases.

BIOCHEMICAL MARKERS

-Several biochemical tests are now available that provide an index of the overall rate of bone remodeling

-These tests measure the overall state of bone remodeling at a single point in time

-markers of bone resorption may help in the prediction of fracture risk, independently of bone density, particularly in older individuals

MANAGEMENT OF OSTEOPOROTIC FRACTURES

-Treatment of the patient with osteoporosis frequently involves management of acute fractures as well as treatment of the underlying disease

-surgical procedures are followed by intense rehabilitation in an attempt to return patients to their prefracture functional level

-For acutely symptomatic fractures, treatment with analgesics is required, including nonsteroidal anti-inflammatory agents and/or acetaminophen, sometimes with the addition of a narcotic agent (codeine or oxycodone).

-Short periods of bed rest may be helpful for pain management, but, in general, early mobilization is recommended as it helps prevent further bone loss associated with immobilization.

-Severe pain usually resolves within 6–10 weeks. Chronic pain is probably not bony in origin; instead, it is related to abnormal strain on muscles, ligaments, and tendons and to secondary facet-joint arthritis associated with alterations in thoracic and/or abdominal shape.

-Chronic pain is difficult to treat effectively and may require analgesics, sometimes including narcotic analgesics

-Frequent intermittent rest in a supine or semireclining position is often required to allow the soft tissues, which are under tension, to relax.

-Back strengthening exercises (paraspinal) may be beneficial

-Heat treatments help relax muscles and reduce the muscular component of discomfort, various physical modalities

-Multiple vertebral fractures are often associated with psychological symptoms, not always commonly appreciated

-Altered balance, precipitated by the kyphosis and the anterior movement of the body’s center of gravity, leads to a fear of falling

MANAGEMENT OF THE UNDERLYING DISEASE

Risk Factor Reduction

-Medications should be reviewed to ensure that all are necessary

- For those on thyroid hormone replacement, TSH testing should be performed to determine that an excessive dose is not being used, as thyrotoxicosis can be associated with increased bone loss

-In patients who smoke, efforts should be made to facilitate smoking cessation.

-Reducing risk factors for falling also includes alcohol abuse treatment and a review of the medical regimen for any drugs that might be associated with orthostatic hypotension and/or sedation, including hypnotics and anxiolytics.

-Patients should be instructed about environmental safety with regard to eliminating exposed wires, curtain strings, slippery rugs, and mobile tables.

NONPHARMACOLOGIC APPROACHES

Protective pads worn around the outer thigh, which cover the trochanteric region of the hip can prevent hip fractures in elderly residents in nursing homes.

TREATMENT MONITORING

There are currently no well-accepted guidelines for monitoring treatment of osteoporosis. Because most osteoporosis. Treatments produce small or moderate bone mass increments on average, it is reasonable to consider BMD as a monitoring tool.

MF3

Report

Osteoporosis

Submitted to: Dr. Gerrard Uy

Sumbitted by: Therese Kimberly Leteral

BSOT - 4

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