Men's Osteoporosis Support Group
Bisphosphonates and colon cancer risk reduction; wrist fracture; walking and BMD; ONJ; zoledronate flu-like symptoms
J Clin Oncol. 2011 Feb 14. [Epub ahead of print]. Use of Bisphosphonates and Reduced Risk of Colorectal Cancer. Rennert G and others. PMID: 21321296. This Israeli study of 933 pairs of postmenopausal female patients and controls matched users of bisphosphonates for more than one year with non-users. They found, after adjustment in a model for vegetable consumption, sports activity, family history of colorectal cancer, body mass index, and use of low-dose aspirin, statins, vitamin D, and postmenopausal hormones there was a 59% reduced relative risk of colorectal cancer (RR, 0.41; 95% CI, 0.25 to 0.67).
Editor's comments. See this article in Bloomberg Business Week for additional details. This type study can't show a causal relationship, but it provides evidence suggesting the need for a controlled clinical trial that might do that. And it appears to be good news for those taking bisphosphonates, such as, Fosamax (alendronate), Boniva (ibandronate), Actonel (risedronate) and Reclast (zoledronic acid).
There were no men in this study so there is even less evidence to indicate they enjoy the same reduced risk of colorectal cancer from bisphosphonate use. Hopefully future clinical trials will include men. In the mean time, it seems logical that they would also have similar results since bisphosphonates work by blocking the osteoclasts, not via any sex-hormone-related mechanism. But there might be a totally different mechanism for colorectal cancer reduction if further studies duplicate these results.
J Bone Joint Surg Am. 2011 Feb;93(4):348-56. Osteoporosis as a risk factor for distal radial fractures: a case-control study. Oyen J and others. PMID: 21325586. This study involved 654 females and 85 males who had low-trauma distal radial (wrist) fractures who were compared to controls. The osteoporosis group included 35% of females compared to 10% of controls. While 17% of males had osteoporosis compared to 13% in controls. In the females, the incidence of osteoporosis went up considerably in the age group of 60-69 years compared to controls: 25% v. 7%. The authors concluded, “The prevalence of osteoporosis in patients with distal radial fractures is high compared with that in control subjects, and osteoporosis is a risk factor for distal radial fractures in both women and men. Thus, patients of both sexes with an age of fifty years or older who have a distal radial fracture should be evaluated with bone densitometry for the possible treatment of osteoporosis.”
Editor's comments. There is a lot of interesting information in the details of this study: 1) Only 17% of the males who had fractures had osteoporosis. Or, 83% of the men who fractured didn't have osteoporosis. 2) Thus, the fall should get credit for the fracture 65% or more of the time in this age group of men and women. That is, it isn't the reduced bone mineral density (BMD), osteoporosis, that accounts for the fracture most of the time, it is the physical fall itself that is sufficient to fracture a bone of normal BMD. Fracture rates correlated to osteoporosis would likely go up significantly as the age of the fracture group rises to the 70s, 80s and higher.
The authors suggest that patients older than 50 years who have distal radius fractures should have bone densitometry done to evaluate the need for osteoporosis treatment. Note that hip and spine fractures get most of the attention on the topic of osteoporosis. But this study is a reminder that wrist fractures are also related to osteoporosis, so don't overlook them as an indication to get your bone density tested.
Brief mention of other osteoporosis studies.
A study by Boyer KA and others, PMID: 21318440, covers the effect of walking on femoral bone density in adults. They didn't find an effect for males, but the results for women are suggestive that, especially for individuals who are 20% lighter in weight than the average, it takes a lot of steps to improve hip BMD: 18,568 steps/day. This compared to 4, 892 for normal weight women. The implication would be that wearing a weighted vest, or similar when walking might be needed especially for low-weight individuals. See this recent Update for more on the topic of exercise, hopping, weighted vests, etc. to increase or maintain hip BMD.
A study by Fellow JL and others, PMID: 21317245, covered the time period of 1995-2006 to find the incidence of osteonecrosis of the jaws. They found a total of 16 cases in a group of 572,606 cohort members . There was a total of 23 cases (0.63 cases per 100,00 patient years), and only six of the 23 cases (26%) had received oral bisphosphonates. They suggest, “Patients with oral bisphosphonates were 15.5 (CI, 6.0-38.7) more likely to have ONJ than non-exposed patients; however, the sparse number of ONJ cases limits firm conclusions and suggests that the absolute risks for ONJ from oral bisphosphonates is low.” Bottom line: the risk of ONJ from oral bisphosphonates is very low, about 0.16 per 100,000 patient years. To find more on this topic go to the Home Page and enter “BONJ” or “ONJ” in the Freefind search block.
A study by Wark JD and others, PMID: 21331467, found that taking acetaminophen/paracetamol or ibuprofen administered 4 h post-infusion reduced the incidence of post-dose influenza-like symptoms from intravenous zoledronic acid (zoledronate, marketed by Novartis as Reclast and Zometa), 5 mg, when given for osteoporosis. This didn't completely stop the incidence of flu-like symptoms, but did significantly reduce them. I think for best results they should have started the patients on a higher dose of the anti-inflammatory medications before they received the IV medications. This is called using a loading dose. The first dose is often bound to carriers in the body and not as effective as additional doses are. The loading dose overcomes this problem by getting the medication to the problem area with the first dose since it both binds to the carrier molecules and is free in the blood stream. So if you are taking zoledronic acid intravenously, I recommend you discuss the use of anti-inflammatory medications and taking a loading dose before the procedure. See this Update for more on zoledronic acid.