A Reminder on Maintaining Bone Health
Published: October 31, 2011
Is fear, ignorance or procrastination putting you at risk of a devastating bone fracture?
Most of the news about osteoporosisconcerns the side effects of current therapies and preventives. But it is important to put these effects in perspective — and to focus on treatment benefits and practical measures that can help to prevent costly and debilitating fractures in fragile bones.
Osteoporosis is both underdiagnosed and undertreated. Doctors say it is underdiagnosed because many who have it fail to get a bone density test, sometimes even after they suffer a fracture. The condition is undertreated because some people avoid drug therapy for fear of side effects, while others take their medications erratically or stop taking them altogether without consulting their doctors.
It is easy to understand the prevailing concern. People hear about drug side effects like osteonecrosis, or bone death, of the jaw (extremely rare and mostly in cancer patients) and unusual fractures of the thigh bone. They hear that supplements of bone-buildingcalcium can increase the risk of heart attack or stroke.
Some 10 million Americans have osteoporosis, and 34 million more with low bone mass are at risk of developing it. It is a silent disease that typically first shows up as a low-trauma fracture of the hip, spine or wrist. Low-trauma does not mean no trauma; someone with healthy bones who falls from a standing height or less is unlikely to break a bone, according to Dr. Sundeep Khosla, president of the American Society for Bone and Mineral Research.
While women are the far more frequent victims of osteoporosis and develop it at a younger age, men — especially those over 70 — are also at risk and even less likely than women to have the disease diagnosed and treated.
New Perspective on Treatment
When drugs called bisphosphonates were introduced to prevent and treat osteoporosis (Fosamax, now available as a generic called alendronate, was the first), overly enthusiastic doctors prescribed them for millions of postmenopausal women who were not at high risk of fracture. These were women whose bone density in the hip or spine measured below that of a healthy 35-year-old but still not near the level associated with osteoporosis.
I was one, and like many others, at age 60 I had what the World Health Organization has labeled osteopenia, not osteoporosis. Osteopenia is defined as a bone density “T-score” between minus 0.1 and minus 2.5, the lower number being the cutoff for osteoporosis.
Osteopenia is analogous to prediabetes or prehypertension, and as with these conditions, Dr. Khosla recommends that most cases of osteopenia are best treated with protective lifestyle measures, not drugs.
Dr. Khosla, a professor of medicine at the Mayo Clinic in Rochester, Minn., suggested in an interview that before turning to drugs, people with osteopenia could try to prevent further bone loss with regular weight-bearing and strength-training exercise, adequate intake of calcium and vitamin D, not smoking and limiting alcohol consumption to one drink a day.
The exceptions — those most likely to benefit from drug treatment even if they do not yet have osteoporosis — include people who already have had a low-trauma fracture and those with a bone density level approaching osteoporosis who also have other risk factors, like earlymenopause, a family history of osteoporosis, the use of steroid drugs (prednisone and others that increase bone loss), extreme thinness, a digestive problem that limits calcium absorption or advanced age.
“Age is itself a major risk factor for fracture,” said Dr. Ethel Siris, director of the osteoporosis clinic at Columbia University Medical Center in New York. Even at the same bone density, a woman of 75 or older is more likely to experience a fall and fracture than a woman of 55.
Dr. Siris explained that with age, changes in the architecture of bones diminish their strength, which can be countered by bisphosphonates. Current thinking in the field, she said, is to place women at risk of fracture on a drug like Fosamax for five years and then perhaps take a one-year drug holiday. For two other bisphosphonates, Actonel and Boniva, she suggests a drug holiday of 6 to 12 months after seven years of treatment.
Benefit Versus Risk
On average, the bisphosphonates reduce the risk of a fragility fracture by 30 to 50 percent. By comparison, the risk of the most talked-about serious side effect — an atypical fracture of the femur, or thigh bone — is minuscule.
A recently published study examined the use of bisphosphonates among 12,777 Swedish women age 55 or older who suffered a fracture of the femur in 2008. Although those who had taken the drugs were 47 times as likely as those who had not to have experienced an atypical femur fracture, the actual number of these fractures was only 5 in 2,000 women who had used the drugs for five years.
Dr. Khosla estimated that the drugs would have prevented more than 100 osteoporotic fractures in these women, a benefit at least 20 times greater than the risk.
Furthermore, this unusual fracture can be prevented because it is preceded by a warning sign — bone changes that cause pain or discomfort in the thigh or groin that persists for weeks or months. If this occurs, Dr. Siris said, you should see your doctor without delay and get an X-ray.
If the X-ray is inconclusive, a bone scan or M.R.I. should follow. If an abnormality is found, Dr. Khosla said, the drug should be stopped and an orthopedist familiar with the problem should be consulted. If keeping weight off the leg does not result in healing, he said, a rod can be surgically inserted in the femur to prevent a fracture.
But Dr. Siris warned against assuming that any pain in the thigh is being caused by the drug. She said too many patients who are at high risk of an osteoporotic fracture stop the drug on their own when in fact the pain could result from sciatica or arthritis in the hip.
As for the risk from calcium supplements, the study that linked them to heart attacks and strokes did not consider how much calcium the women consumed.
Dr. Siris, among others, recommends 1,200 milligrams a day from diet alone or a combination of diet and a supplement. She noted that each serving of dairy (a cup of milk or yogurt or chunk of cheese) provides about 300 milligrams, and most people get another 200 or 300 from nondairy sources.
She said, “If too little calcium is consumed, parathyroid hormone will take calcium from the bones to maintain a normal blood level” of this essential mineral. Vitamin D — about 1,000 to 2,000 international units a day — is also important to assure adequate calcium absorption, especially for those “with bad bones,” she said.