Definition

Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures, especially of the hip, spine and wrist, although any bone can be affected.

Prevalence

Osteoporosis is a major public health threat for an estimated 44 million Americans, or 55 percent of the people 50 years of age and older.  In the U.S. today, 10 million individuals are estimated to already have the disease and almost 34 million more are estimated to have low bone mass, placing them at increased risk for osteoporosis.

Of the 10 million Americans estimated to have osteoporosis, eight million are women and 2 million are men.

Thirty-four million Americans have low bone mass, which puts them at increased risk of developing osteoporosis and related fractures.

One in two women and one in four men over age 50 will have an osteoporosis-related fracture in her/his remaining lifetime.

Significant risk has been reported in people of all ethnic backgrounds.

While osteoporosis is often thought of as an older person's disease, it can strike at any age.

Women

Eighty percent of those affected by osteoporosis are women.

Five percent of non-Hispanic black women over age 50 are estimated to have osteoporosis; an estimated additional 35 percent have low bone mass that puts them at risk of developing osteoporosis.

Ten percent of Hispanic women aged 50 and older are estimated to have osteoporosis, and 49 percent are estimated to have low bone mass.

Twenty percent of non-Hispanic white and Asian women aged 50 and older are estimated to have osteoporosis, and 52 percent are estimated to have low bone mass.

 Men

Twenty percent of those affected by osteoporosis are men.

Seven percent of non-Hispanic white and Asian men aged 50 and older are estimated to have osteoporosis and 35 percent are estimated to have low bone mass.

Four percent of non-Hispanic black men aged 50 and older are estimated to have osteoporosis and 19 percent are estimated to have low bone mass.

Three percent of Hispanic men aged 50 and older are estimated to have osteoporosis and 23 percent are estimated to have low bone mass.

Fractures

One in two women and one in four men over age 50 will have an osteoporosis-related fracture in their remaining lifetime.

Osteoporosis is responsible for more than 1.5 million fractures annually, including:

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  over 300,000 hip fractures; and approximately

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  700,000 vertebral fractures;

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  250,000 wrist fractures; and

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  300,000 fractures at other sites.

The estimated national direct expenditures (hospitals and nursing homes) for osteoporotic hip fractures was $18 billion in 2002, and the cost is rising.

Osteoporosis is often called the "silent disease" because bone loss occurs without symptoms.  People may not know that they have osteoporosis until their bones become so weak that a sudden strain, bump or fall causes a fracture or a vertebra to collapse.  Collapsed vertebrae may initially be felt or seen in the form of severe back pain, loss of height, or spinal deformities such as kyphosis or stooped posture.

Certain people are more likely to develop osteoporosis than others.  Factors that increase the likelihood of developing osteoporosis are called "risk factors."  These risk factors include: 

•   Personal history of fracture after age 50
• Current low bone mass
• History of fracture in a 1° relative
• Being female
• Being thin and/or having a small frame
•   Advanced age
• A family history of osteoporosis
•   Estrogen deficiency as a result of menopause, especially early or surgically induced
•   Abnormal absence of menstrual periods (amenorrhea)
•   Anorexia nervosa
•  Low lifetime calcium intake
• Vitamin D deficiency
• Use of certain medications, such as corticosteroids and anticonvulsants
•   Presence of certain chronic medical conditions
• Low testosterone levels in men
• An inactive lifestyle
• Current cigarette smoking
•   Excessive use of alcohol
• Being Caucasian or Asian, although African Americans and Hispanic Americans are at significant risk as well

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. 

Specialized tests called bone density tests can measure bone density in various sites of the body.  A bone density test can:

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  Detect osteoporosis before a fracture occurs.

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  Predict your chances of fracturing in the future.

• DXA BMD can determine your rate of bone loss and/or monitor the effects of treatment.

By about age 20, the average woman has acquired 98 percent of her skeletal mass. Building strong bones during childhood and adolescence can be the best defense against developing osteoporosis later. There are five steps, which together, can optimize bone health and help prevent osteoporosis.  They are:

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  A balanced diet rich in calcium and vitamin D;

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  Weight-bearing exercise;

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  A healthy lifestyle with no smoking or excessive alcohol intake;

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  Talking to your healthcare professional about bone health; and

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  Bone density testing and medication when appropriate.

The most typical sites of fractures related to osteoporosis are the hip, spine, wrist and ribs, although the disease can affect any bone in the body. 

 The rate of hip fractures is two to three times higher in women than men; however the one year mortality following a hip fracture is nearly twice as high  for men as for women.    

 A woman's risk of hip fracture is equal to her combined risk of breast, uterine and ovarian cancer.

 In 1991, about 300,000 Americans age 45 and over were admitted to hospitals with hip fractures. Osteoporosis was the underlying cause of most of these injuries.

An average of 24 percent of hip fracture patients aged 50 and over die in the year following their fracture.

One-fourth of those who were ambulatory before their hip fracture require long-term care afterward.

At six months after a hip fracture, only 15% of hip fracture patients can walk across a room unaided.

White women 65 or older have twice the incidence of fractures as African-American women.