Bone Markers Indicate Early Response to Osteoporosis Therapy
I believe that the authors of this study have been living in a cave for at least 5 or more years. The concept of using markers of bone breakdown found in the urine has been using by functional medicine practitioners for many years now. In any of my osteoporosis presentations in the community, I always point out that checking only for bone mineral density is not only slow, it is incomplete. A patient needs to know how dense their bones are, but also how fast or slow that bone is being broken down. In addition, these markers can be used to determine if an osteoporosis program (note I said “program”, not calcium supplementation…) is having a positive effect on bone turnover. It is a simple urine test that costs under $100.
23rd Annual Meeting of the American Society for Bone and Mineral Research New findings suggest that assessment of bone resorption markers during the first 3 to 6 months of osteoporosis treatment may be a useful alternative to the conventional method of evaluating therapeutic response, measurement of bone mineral density after 2 years. At the 23rd Annual Meeting of the American Society for Bone and Mineral Research, Dr. Richard Eastell of the University of Sheffield in the UK presented the results of a study that measured N-telopeptide and C-telopeptide of type I collagen in urine samples from 2442 women with postmenopausal osteoporosis who had sustained at least one vertebral fracture. All of the women had been treated with a calcium supplement (and vitamin D, if needed), and they had been randomized to risedronate 5 mg/day or placebo for 3 years. Decreases in bone turnover measured 3 to 6 months after the start of treatment accounted for approximately 50% of risedronate’s 1-year effect against vertebral fractures and about 66% of the vertebral fracture risk reduction associated with the medication over 3 years, the researchers reported. The results also showed that the relationship between fracture risk and bone resorption rate was not linear and that reduction beyond 60% was associated with no additional decrease in fracture risk. As in prior trials, risedronate was shown to suppress bone resorption by a mean of 50% to 60%. “This is the first time that we can document a link between decreases in bone resorption markers and reductions in fracture risk,” said Dr. Eastell . The findings suggest that measuring bone resorption markers may serve as a useful tool for evaluating response to osteoporosis therapy, he added. Besides the 1- to 2-year period of uncertainty, Dr. Eastell noted, the standard method of evaluating osteoporosis therapy is limited in that increases in bone mineral density are responsible for only about 20% of the fracture risk reduction seen with current therapies.