BONE DENSITY TESTING

                                    BODY COMPOSITION TESTING

Prevalence of Osteoporosis in the United States

-  Twenty-five million people have osteoporosis.
-  Osteoporosis is responsible for over 1 million fractures every year including 250,000 hip    fractures, 500,000 vertebral fractures, 125,000 wrist fractures and over 125,000 fractures at other sites.
-  Hip fractures lead to as many as 50,000 deaths annually.
-  The incidence of osteoporosis is expected to double by the year 2020.
-  The risk of a Caucasian person developing an osteoporotic hip fracture in her or his own life is about 17%.

The Cost of Osteoporosis

-  The average cost for hospitalization due to hip fracture is $26,000, excluding physician fees.
-  The total annual cost in the United States of treating osteoporosis is $10 billion; the cost of treating hip fractures alone is $7 billion.
-  As the population ages, the annual cost of treating osteoporosis is expected to increase to $30 billion by year 2020.

Living with Osteoporosis

-  When vertebrae are affected by osteoporosis, it may cause loss of height, deforming curvature of the spin, and back pain.
-  One-half of those who could walk unaided before a hip fracture cannot do so afterwards.
-  Seven percent of women become unable to care for themselves after suffering an osteoporotic fracture.

 Osteoporosis and Women

-  Eighty percent of those with osteoporosis are female.
-  One-third to one half of all postmenopausal women are affected by osteoporosis.
-  The risk of hip fracture is 2-3 times higher for women than for men; spinal osteoporosis is 8 times more likely to affect women than men.
-  At age 50 a Caucasian woman has a 54% chance of an osteoporotic fracture in her remaining life.
-  After the age 50 a woman’s risk of developing osteoporosis doubles every 5 years.
-  For the average woman, the risk of developing osteoporosis is greater than the combined risks of developing endometrial (cancer of the uterus) or breast cancer.
-  Bone loss in women tends to begin at age 35 at a rate of 0.5-1% per year. This can increase to 3-7% per year for the first 3-5 years after menopause.
-  Post-menopausal hormone replacement can reduce the risk of developing osteoporotic fractures by up to 50%.
-  A women who takes at least 10 days of progesterone in addition to estrogen replacement after menopause is estimated to have a 10% lower risk of endometrial cancer than a woman who takes no hormones.

Indications for Bone Densitometry

 -  Osteopenia on routine x-ray, and thus, need for confirmation of the subjective suspicion of low bone mass.
-  When assistance is needed in making a decision regarding HRT or other nonhormonal therapy.
-  Glucocorticoid therapy or Cushing’s syndrome.
-  Primary hyperparathyoidism, to assist with decisions regarding surgical intervention.
-  After organ transplantation.
-  Maternal history of fracture.
-  Prolonged immobilization.
-  Renal failure – to monitor the effects of excess parathyroid hormone.
-  Liver disease.
-  Excess thyroid hormone production or administration.
-  Malabsorption syndromes.
-  Height loss greater than 4cm.
-  Weight loss greater than 5kg.
-  Rheumatoid arthritis, even without Glucocorticoid therapy.

Who should be tested.

-  All postmenopausal women under 65 who have one or more additional risk factors for osteoporotic fracture.
-  All women aged 65 and older regardless of additional risk factors.
-  Postmenopausal women who present with fractures (to confirm diagnosis and determine disease activity).
-  Women who are considering therapy for osteoporosis, if BMD testing would facilitate the decision.
-  Women who have been on hormone replacement therapy for prolonged periods.

Defining Osteoporosis by BMD

The World Heath Organization (WHO) has established the following definition based bone density measurement at any skeletal site in white women:

 Normal:            T-score above –1 (BMD is within 1 SD of a “young normal” adult)

Osteopenia:       T-score between –1 and –2.5 (BMD is between 1 and 2.5 SD below that of a “young normal” adult)

Osteoporosis:    T-score at or below –2.5 (BMD is 2.5 SD or more below that of a “young normal” adult. Women in this group with one or more fractures are deemed to have severe “Established” osteoporosis.)

Although these definitions are necessary to establish the prevalence of osteoporosis, they should not be used as the sole determinant of treatment decisions.

Who should have a bone density test?

The National Osteoporosis Foundation (NFO) is a leading source of information about osteoporosis and bone measurement. 

The NOF recommends women have a bone density test if they are:

-  Over 65 years old
-  Post menopausal
             - with at least one risk factor besides menopause
             - with a fracture
-  Considering osteoporosis therapy
-  On prolonged hormone replacement therapy.

Who should be treated?

   The NOF recommends considering treatment if:
            -  T-score <-1.5 with risk factors
            -  T-score <-2 with no risk factors
            -  Postmenopausal with a fracture

National Osteoporosis Foundation

RISK FACTORS FOR OSTEOPOROTIC FRACTURE

Potentially modifiable:

-  Current cigarette smoking
-  Low body weight (<127lbs)
-  Estrogen deficiency:
                        Early menopause (<age 45)
            Or bilateral ovariectomy
                        Prolonged premenopausal
                                    Amenorrhea (>1 year)
-  Low calcium intake (lifelong)
-  Impaired eyesight despite adequate correction
-  Recurrent falls
-  Inadequate physical activity
-  Poor health / frailty 

Nonmodifiable:

-  Personal history of fracture as an adult
-  History of fracture in first-degree relative
-  Caucasian race
-  Advanced age
-  Female sex
-  Dementia
-  Poor health / frailty

DISEASE AND DRUGS ASSOCIATED WITH AN INCREASED RISK OF OSTEOPOROSIS

All content Copyright Barbara A. Hrach M.D FACP 2005