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Osteoporosis: Evaluation and Treatment

by Joyce Baldwin

Geriatric Times November/December 2000 Vol. I Issue 4

Ten million Americans have been diagnosed with osteoporosis; another 18 million have low bone mass. Information about preventing, evaluating and treating these conditions is growing rapidly, according to participants in a National Institutes of Health (NIH) Consensus Development Conference on Osteoporosis. The conference, held in March and sponsored primarily by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMSD), highlighted the latest scientific evidence of osteoporosis in men, optimal treatment strategies and monitoring treatment.

"Twenty-five years ago we didn't know that bone was constantly being built up and broken down," said Stephen I. Katz, M.D., Ph.D., director of NIAMSD, in an interview with Geriatric Times. "Much of this information has been developed in the last 15 years, but it is really only in the last five years that physicians had a good idea that they could manipulate the system with medications, either by blocking cells that break down bones or with drugs that can encourage the buildup of bone.

"We've also come to appreciate in the last 10 years that secondary osteoporosis [in] people getting corticosteroids and other immunosuppressive therapy as well as [in] those with other conditions or diseases, is a significant issue," he continued.

Although postmenopausal women experience most hip fractures due to osteoporosis, data show that as many as one-third of all such fractures occur in men. To better understand the nature and course of osteoporosis in men, the NIH has awarded a $23.8 million grant to initiate a seven-year, multicenter study of 5,700 men over the age of 65. Since men are now living longer, they can be expected to comprise a greater proportion of the osteoporotic population in the future. Eric S. Orwoll, M.D., principal investigator of the NIH grant and a presenter at the conference, told GT, "There are very few men who get bone density testing now, and I think it would be reasonable that many more do."

Orwoll, professor of medicine at the Oregon Health Sciences University in Portland, said physicians "often dismiss a low-trauma fracture or vertebral deformity on chest X-ray as merely trauma or old age, and even classic osteoporotic fractures are frequently ignored." In evaluating men, he said, physicians should consider whether a patient has risk factors for bone loss. For instance, the physician should question whether the patient takes glucocorticoids; has a condition such as gonadal dysfunction, kidney disease or malabsorption; smokes; or consumes excessive alcohol.

The NIH consensus statement delineated a range of preventive strategies for both men and women, including exercise, adequate intake of calcium and vitamin D, and treatment with bisphosphonates, hormone replacement therapy (HRT) and selective estrogen receptor modulators (SERMs), which have been demonstrated to reduce the risk of vertebral fracture by 36%. The conference participants agreed that natural estrogens, particularly plant-derived phytoestrogens, show some promise, but no effects on fracture reduction have been shown. Salmon calcitonin, the consensus statement said, "has demonstrated positive effects on [bone mineral density] at the lumbar spine, but this effect is less clear at the hip." The statement also pointed to promising studies on improving strength and balance in elderly people, the use of hip protectors to absorb or deflect the impact of a fall, and ways to prevent falls.

Treatment protocols using a combination of therapies were presented by Robert R. Recker, M.D., professor of medicine, chief of the endocrinology division and director of the Osteoporosis Research Center at Creighton University. "HRT, in particular Premarin [conjugated estrogens] but others as well, combined with calcium and vitamin D is more powerful than without calcium and vitamin D, and still more powerful if given with a bisphosphonate," he told GT.

Recker said a prior study showed that a "low dose of 0.3 mg per day of Premarin combined with calcium and vitamin D demonstrated bone mass responses equivalent to and even greater than conventional doses of 0.625 mg per day of Premarin, rivaling the bone mass effects of bisphosphonates [Recker et al., 1999]." To ensure that patients are getting the proper amount of vitamin D, thought to be 400 IU to 1000 IU daily, Recker said, "I prescribe it in an over-the-counter preparation that contains nothing but vitamin D. The reason is that I worry whether you can trust the multi-ingredient formulations containing vitamin D because the D may deteriorate on the shelf. Vitamin D is somewhat delicate; it doesn't last well on the shelf. Almost every chemical you put in contact with it, degrades it. So I'm not confident that the vitamin D contained in multivitamins and other products is reliable.

"That's a contentious statement because this has not been given enough research attention," he continued. "The multi-ingredient vitamin D preparations are not regulated by the U.S. Food and Drug Administration; they are regulated by the U.S. Department of Agriculture. All [manufacturers] have to do by regulation is assure that they have the content of vitamin D on the label as it leaves the factory."

Another issue the consensus statement addressed is that of monitoring patients who are undergoing treatment. Many patients do not comply with recommended treatment protocols, and monitoring by densitometry has not been shown to improve compliance.

In discussing the accuracy of serial monitoring of bone density, Recker said, "It's difficult to know for sure just what we should be doing about it. The problem is that the range of changes that we see in patients on treatment, the range of improvements that we see, are within or near the range of precision of the measurement. And so we have a dilemma.

"If these serial measurements don't show an increase in bone mass in a patient on treatment, one may…be tempted to stop it and try something else. The trouble is the decreases, or lack of increases, in bone mass are almost always a statistical artifact. A patient should not be taken off effective medication because they did not see, say, a 5% increase in bone mass."

If patients remain compliant and are comfortable with not being tested, Recker said physicians should measure bone mineral density after two or more years of treatment, "because as more time passes, the bone gain is greater, so the statistical artifact will be less manifest."

Since patients may not view their treatment as credible if they are not being monitored, Recker advised physicians to continue to measure bone density, but to urge patients to wait to see results.

Another topic that emerged from the conference was the importance of protein and calorie malnutrition as risk factors for osteoporosis in older people. "It's amazing that as many as two-thirds of the women admitted to hospital with hip fracture show biochemical evidence of under-nutrition," Recker said.

"You can have protein malnutrition without calorie malnutrition among the elderly. Nutritional intervention, oral or parenteral, in hospitalized patients with hip fractures reduces morbidity, reduces length of stay and improves outcomes. But this kind of intervention is rare…We should be paying attention to the whole patient when they come in with a hip fracture, treating their malnutrition and other problems as well as their osteoporosis while we're pinning their hips."

The consensus conference developed a list of directions for future research which include:

Reference

Recker RR, Davies KM, Dowd RM, Heaney RP (1999), The effect of low-dose continuous estrogen and progesterone therapy with calcium and vitamin D on bone in elderly women. A randomized, controlled trial. Ann Intern Med 130(11):897-904.