Osteoporosis management remains a challenge for endocrinologists

American Association of Clinical Endocrinologists 20th Annual Meeting

SAN DIEGO — Despite new guidelines and updated tools, diagnosing and treating patients with osteoporosis remains a challenge, a speaker said here.

Nelson B. Watts, MD, professor of medicine at the University of Cincinnati College of Medicine, said today “there are new guidelines on calcium and vitamin D, new recommendations for testing for postmenopausal osteoporosis and new concerns about old treatments.

Confusion about calcium intake

Recent Institute of Medicine (IOM) guidelines recommend adults receive between 1,000 mg and 1,200 mg of calcium daily, based on age and sex. Most people consume 300 mg daily from low-calcium foods, according to Watts. The additional 900 mg is easily achieved by taking advantage of calcium-fortified foods or through supplementation, he said. Nevertheless, as patients discover new avenues for increasing calcium intake, such as soft, flavored, chewable tablets, they often surpass the recommended daily allowance.

Until the publication of a 2010 meta-analysis by Bolland et al in British Medical Journal, people were generally unconcerned about excessive calcium intake. However, the study of trials involving women with osteoporosis suggested that patients receiving more than 1,500 mg of calcium daily had increased risk for myocardial infarction.

“It is important to realize that you can get too much of a good thing,” Watts said during a presentation. “Some patients we see in our practice are getting plenty of calcium from their diet in addition to supplements and wind up with total daily intakes of 3,000 mg or 3,500 mg. No data suggest that there is value in going over 1,200 mg, so many people should leave physicians’ offices with instructions to take less calcium rather than more.”

Disparities in vitamin D recommendations

The IOM guidelines also introduced new recommendations for vitamin D intake based on a report from the organization’s committee. The report states that a 25-hydroxyvitamin D level of 20 ng/mL is sufficient for bone health, explaining that almost everyone either already has or can achieve this target level.

In addition, the committee determined that levels of 50 ng/mL or higher may be harmful based on a study that showed an increased number of falls and fractures among people with vitamin D levels higher than 50 ng/mL. Watts pointed out, however, that many outdoor workers, such as lifeguards, exceed this upper limit, yet no recommendations suggest that they lower their vitamin D levels. Further, no studies have examined the long-term benefits and harms of vitamin D levels higher than 50 ng/mL, he noted.

“AACE was quick to jump in on the IOM report because many physicians were using 30 ng/mL as the minimum desirable level and AACE said it would be appropriate to use a range between 30 ng/mL and 50 ng/mL as an optimal and safe range,” Watts said.

To maintain a blood level within that range, most people would require 1,000 IU to 2,000 IU of vitamin D daily. Since this range is well below the safe upper limit of 4,000 IU daily, recommended dosing of 1,000 IU to 2,000 IU is reasonable, according to Watts. It is also essential that physicians use clinical judgment and bear in mind that the IOM recommendations are for healthy adults residing in North America and do not take into account other important factors, such as disease state, he said.

Screening issues, treatment controversies

To address the issue of screening, the US Preventive Services Task Force recently released evidence-based guidelines that recommend routine screening of postmenopausal women aged older than 65 years. They also suggest screening for younger women whose fracture risk is equal to or greater than that of a 65-year-old woman with no additional risk factors.

Watts noted that many physicians may be uncertain about how to determine if a younger postmenopausal woman has the same fracture risk as a 65-year-old woman. For physicians in this position, the FRAX tool may be extremely helpful, he said. Even so, the FRAX tool has undergone several updates since its inception, and therefore, physicians may need to revisit some of their previous calculations. He also emphasized that FRAX is a dynamic tool, and a physician should conduct new analyses as patients’ circumstances change. A recent hip fracture, for example, may place a low-risk patient within the treatment range.

Controversies regarding pharmacological therapies for osteoporosis have also emerged in recent years, with treatments such as bisphosphonates being blamed for atypical femur fractures. These atypical fractures, however, are uncommon, Watts said, but physicians should still carefully monitor their patients for complaints of thigh pain or other health problems. – by Melissa Foster

For more information:

• Watts NB. General session. Management of controversies in osteoporosis. Presented at: American Association of Clinical Endocrinologists 20th Annual Meeting; April 13-17, 2011; San Diego.

Disclosure: Dr. Watts is co-founder, stockholder and director of OsteoDynamics; has received honoraria from Amgen, Novartis and Warner Chilcott for lectures in the past year; has received consulting fees from Amgen, Arena, Baxter, InteKrin, Johnson & Johnson, Lilly, Medpace, Merck, NPS, Orexigen, Pfizer/Wyeth, Sanofi-Aventis, Takeda, Vivus and Warner Chilcott in the past year; and has received research support from Amgen, Merck and NPS through his university.

[This topic] strikes a nerve. Osteoporosis is something that endocrinologists deal with regularly, and there are controversies as to what are the best treatment modalities. Dr. Watts was very thorough in presenting both sides of the issue.

– Eric A. Orzeck, MD
Endocrinology Associates
Houston, TX

Disclosure: Dr. Orzeck reports no relevant financial disclosures.

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