Some new osteoporosis-related studies
Use of a fully human monoclonal antibody to RANKL. RANKL is an essential osteoclastic differentiation and activation factor, so if you could block it, you should be able to prevent the osteoclastic breakdown of bone that occurs in osteoporosis. This should bring about a net gain in bone mineral density (BMD). This study is in J Bone Miner Res. 2004 Jul;19(7):1059-66 by Bekker PJ and others. PMID: 15176987. The authors tested six cohorts of eight to nine postmenopausal women with increasing doses of AMG 162, a fully human monoclonal antibody to RANKL. During the following six or nine months (for high-dose cohorts) the subjects were tested for the effect on bone turnover markers. The authors found, "A single subcutaneous dose of AMG 162 resulted in a dose-dependent, rapid (within 12 h), profound (up to 84%), and sustained (up to 6 months) decrease in urinary NTX. At six months, there was a mean change from baseline of -81% in the 3.0 mg/kg AMG 162 group compared with -10% in the placebo group; serum NTX changes were -56% and 2%, respectively." The highest doses of AMG 162 caused 3-fold increase in parathyroid hormone levels, but this returned to normal after follow up. The authors note, "In summary, a single subcutaneous dose of AMG 162 resulted in a dose-dependent rapid and sustained decrease from baseline in bone turnover and could be an effective and convenient treatment for osteoporosis." Editor's comments: This looks like very exciting research with strong implications for those with osteoporosis. A single injection once or twice yearly that would treat osteoporosis would indeed be a simple and desirable method of treatment. Keep checking for follow-up research on this exciting topic.
The importance of bisphosphonate therapy in maintaining bone mass after therapy with teriparatide (human parathyroid hormone [1-34]). Teriparatide (Forteo) has been shown in multiple studies to be an extremely effective way to increase BMD. But, it has been shown that it isn't as effective if bisphosphonates, such as Actonel or Fosamax, are taken along with the Forteo. See the recent update concerning this topic at this Website. A new study shows, however, that it is important to continue with bisphosphonate therapy after the relatively short-term (one or two years) Forteo therapy stops. See: Osteop Int. 2004 Jun 3 by Kurland ES and others. PMID: 15175844. The authors followed 21 men for up to 2 years after discontinuing teriparatide. 57% of the men chose to take bisphosphonates immediately after stopping Forteo, 43% opted for no medication. The men taking bisphosphonates had 5.1% additional increase in BMD while those not taking medication had 3.7% decline in BMD. Note that the men who had two years of Forteo and two years of bisphosophonate had total gains in BMD in the lumbar spine of 23.6%. This is compared to a mere 5.5% gain in BMD in those men who only had two years of Forteo with no follow-up bisphosphonates. The authors conclude, "The immediate use of bisphosphonates after teriparatide withdrawal may help to optimize gains in bone density at the lumbar spine." Editor's comments: Thus, it is very important to take bisphosphonates after completing the Forteo, just as it is important not to include the bisphosphonates while taking Forteo.
Benefits of 2 years of intense exercise on bone density and other factors. See: Arch Intern Med. 2004 May 24;164(10):1108-12 by Kurland ES and others. PMID: 15159265. It is common knowledge that weight-bearing exercise is important for maintaining or improving BMD. This study looked at the potential benefit of intense exercise, not only on BMD, but whether this exercise might also benefit serum lipid levels and other elements of physical fitness. This was a 26-month study with 50 women who trained as a group twice weekly at a fitness center, as well as twice weekly alone at home. This group was compared to33 women who were nontraining controls. Results showed that the exercise group improved significantly compared to baseline (relative to the controls) as concerns physical fitness, maximum oxygen consumption, BMD of the lumbar spine and total hip, serum levels of total cholesterol and triglycerides and pain indexes of the spine. The authors concluded: "General purpose exercise programs with special emphasis on bone density can significantly improve strength and endurance and reduce bone loss, back pain, and lipid levels in osteopenic women in their critical postmenopausal years." Editor's comments: As always, this study tested only women, but there is no reason to believe that men wouldn't benefit similarly with a program of intense exercise. But, note that these women didn't have osteoporosis, they were simply osteopenic. If you determine you would like to start this type intense exercise program, be sure you check with your care provider to verify that your program will not put you at risk for bone fracture due to your osteoporosis.