Do You Have Brittle Bones?

Osteoporosis is a disease of ‘brittle bones’ that is underdiagnosed and undertreated. According to the National Osteoporosis Foundation (NOF), one in three women and one in nine men over 80 years old will have a hip fracture related to osteoporosis, and 15 to 30 percent will die of related complications. For women over 50, the risk of dying of hip fracture is the same as dying of breast cancer, and for men over 50, the risk of dying of hip fracture is greater than the risk of dying of prostate cancer. About half of people who have osteoporosis are neither diagnosed nor treated.

Osteoporosis is characterized by a progressive decrease in bone density, causing bones to become weak, brittle and easily fractured. It is most common in women after menopause because of the reduced production of estrogen. The most common manifestation of osteoporosis is a fractured spinal bone or vertebra. These vertebral fractures may occur without symptoms or may cause back pain. They are commonly associated with loss of height and the ‘dowager’s hump.’ Hip fractures and fractures of the forearm near the wrist are also common in people with osteoporosis.

People at high risk for osteoporosis include women after menopause, women who have had a one-year absence of menstruation prior to menopause, and people with an overactive thyroid gland or an overactive parathyroid gland. Other risk factors include prolonged therapy with steroids; low body weight (less than 127 pounds); current cigarette smoking; Caucasian; advanced age; lifelong low calcium intake; and inadequate physical activity. In people who have osteoporosis, any condition that increases their risk of falling–including alcoholism, poor health, dementia and poor vision–also increases the risk of a fracture.

Osteoporosis can be diagnosed by measuring bone density. The World Health Organization defines ‘normal bone density’ as a value within one standard deviation (SD) of the mean in young adults of the same sex and race. A standard deviation is a statistical figure based on measurements of bone mineral density (BMD) in normal subjects. A BMD that is between 1 and 2.5 SD below the mean is considered osteopenia–that is, bones that are thinner than normal but not yet as fragile as in osteoporosis.

Several methods are used to measure BMD. Ultrasound of the heel is performed in some physicians’ offices. Other patients receive a DEXA, the most popular screening method, which evaluates BMD at the spine and hip, the most common fracture sites. This test is usually performed in hospital x-ray departments and is quick and painless. The National Osteoporosis Foundation currently recommends screening all women under age 65 who have one or more risk factors in addition to menopause. Screening is also recommended for all women 65 years of age and older.

The NOF also recommends that all adults should be counseled about risk factors for osteoporotic fractures, particularly stopping smoking, limiting alcohol consumption and participating in regular exercise. All adults should be advised to obtain an adequate supply of calcium and vitamin D, either through diet, supplements or a combination.

Women whose BMD is below 2 should consider drug therapy. Several classes of medication are available. Bisphosphonates, including alendronate (Fosamax) and risedronate (Actonel), increase BMD and reduce new vertebral fractures by 40 to 60 percent. However, they can cause stomach pain, diarrhea, nausea, and vomiting, and many women cannot tolerate them. Selective estrogen-receptor modulators, most commonly Raloxifene (Evista), seem to be as effective but may cause hot flashes and an increased risk of blood clots. Teriparatide is the newest drug available and actually stimulates new bone formation. Unfortunately, this drug is only available by daily injection. A number of new drugs are in the testing phase, including a bisphosphonate which only needs to be given once a year, reducing most of the usual side effects.

Dr. McMahon, a graduate of Yale University and the University of Pittsburgh School of Medicine, is board certified in Internal Medicine. She is a member of the American College of Physicians and the Allegheny and Pennsylvania Medical Societies. She is in solo practice in the North Hills.