To the Bone: Experts Discuss Developments in Osteoporosis Care

Bone Turnover Markers

Richard Eastell, MD, professor of bone metabolism at the University of Sheffield, U.K., said that bone turnover markers offer crucial information that has important implications for osteoporosis treatment. However, these markers are not used often.

BMD changes take about 18 months before providing a solid read on treatment efficacy—a rather a long time, he said. Bone turnover markers, such as CTX and Procollagen 1 Intact N-Terminal Propeptide (P1NP), give a faster indication of a patient’s response.

“They respond early and to a larger extent than, for example, bone density when we give anti-resorptive treatments,” he said. “This [fact] makes them an ideal marker because we can make the measurement before we have any problems with adherence.”

In the PINP and Osteoporosis in Sheffield Evaluation (POSE) study, researchers assessed a group of patients who had their P1NP monitored and another that didn’t.⁵ A significantly higher number of patients with P1NP monitoring had a change in osteoporosis management, as well as a significantly greater improvement in BMD after five years, than patients without P1NP monitoring. An incremental cost-effective ratio analysis found P1NP monitoring to be cost-effective.

A retrospective claims database analysis found that only 6,075 of 457,829 patients with osteoporosis had bone markers measured and that marker testing was associated with a lower risk of fractures.⁶

“The use of bone turnover markers does seem to be helping decision making,” said Dr. Eastell, “but the uptake has been low.”  

In a discussion at the end of Dr. Eastell’s presentation, one attendee said she had been using these markers, but insurance coverage became problematic. Thus, she stopped using them. He noted that in the U.K., the tests cost about $15.

“We don’t have the problem that you have. It’s partly because the bone markers are so much less expensive,” Dr. Eastell said. “The issue about insurance is an important issue in relation to the American practice.”

Vitamin D

Ms. Weaver

Connie Weaver, professor of exercise and nutritional sciences at San Diego State University, said recent research has shown that the 25-hydroxy vitamin D (25[OH]D) test is not the ideal measure for monitoring vitamin D levels.

Free vitamin D accounts for just 1% of a person’s vitamin D levels, she said. Researchers have found the 10–15% is bound to albumin, and about 85% is bound to the vitamin D binding protein and is likely inert.⁷