Men's Osteoporosis Support GroupStrontium ranelate safety and osteopontin as a risk factor for osteoporosis Age Ageing. 2010 Mar 17. [Epub ahead of print]. Severe exfoliative dermatitis caused by strontium ranelate: two cases of a new drug reaction. Smith EV, Shipley DR. PMID: 20299323. This Update will provide two articles that report on incidence of adverse risk related to taking strontium ranelate for osteoporosis. The first is a U.K. article that reports the first two cases of exfoliative dermatitis related to taking strontium ranelate for osteoporosis. The authors note there is significant morbidity related to this condition and that systemic steroid treatment is needed. Br J Clin Pharmacol. 2008 Nov;66(5):689-94. Epub 2008 Jul 31. Post-marketing assessment of the safety of strontium ranelate; a novel case-only approach to the early detection of adverse drug reactions. Grosso A and others. PMID: 18754840. Free full text available online. The second article is also from the U.K. and is a self-controlled case-series method study. It involved the UK General Practice Research Database and checked for the incidence of recently reported adverse events linked to the use of strontium ranelate for osteoporosis in postmenopausal women. They found, "Age-adjusted rate ratios for venous thromboembolism, gastrointestinal disturbance, minor skin complaint and memory loss were 1.1 [95% confidence interval (CI) 0.2, 5.0], 3.0 (95% CI 2.3, 3.8), 2.0 (95% CI 1.3, 3.1) and 1.8 (95% CI 0.2, 14.1), respectively. No cases of osteonecrosis of the jaw, toxic-epidermal necrosis, Stevens-Johnson syndrome or drug rash with eosinophilia and systemic symptoms were found." Editor's comments. There are previous Updates on the topic of strontium ranelate. None of these has reported any difference in adverse events when compared to controls. So the Smith and Shipley study is the first to apparently report any serious complications related to strontium use. The Grosso study appears to show that their self-controlled case-series method shows an increase in the rate of adverse events when compared to that reported in previous clinical studies. Strontium ranelate is not yet FDA-approved in the U.S. to my knowledge. But when it is, patients should be aware that it, like most medications, is not free from the risk of adverse events. And the exfoliative dermatitis, though apparently quite rare, is very serious. Osteoporos Int. 2010 Mar 18. [Epub ahead of print]. Increased serum osteopontin is a risk factor for osteoporosis in menopausal women. Chang IC. PMID: 20238102. This study involved 124 menopausal women older than age 45 compared to younger, premenopausal women aged 25 to 45. Each group was tested for serum concentration of osteopontin (OPN) to see if this could act as a biochemical marker of osteoporosis risk. The results showed several correlations between osteopontin and multiple variables in the menopausal group, but none in the premenopausal group. Most importantly they found, ". . .high serum OPN levels (>14.7 ng/ml) was a significant risk factor causing menopausal osteoporosis (odds ratio = 2.96, 95% confidence interval, 1.055-8.345)." The authors concluded, "Serum OPN levels could be used as a biomarker for the early diagnosis of osteoporosis in postmenopausal women." Editor's comments. This study involved only women because menopausal women are ideal test subjects for osteoporosis, not because osteopontin wouldn't also be a good marker for men's osteoporosis. It is a protein having its effect on osteoblasts (bone-forming cells), and not related to gender whatsoever. I suspect it will be quite some time before serum osteopontin testing is done as it will take a while for these results to filter out of the research field to the clinical area. In the meantime I could imagine several areas where this test might be helpful that I hope future research will shed light upon. For instance, a recent Update reported that after five or more years of taking a bisphosphonate it might be wise to take a holiday from the medication. Evaluating serum osteopontin, perhaps yearly or every other year, might be a good way to know when it is time to restart the bisphosphonate: when osteopontin levels started to approach 14 ng/ml. Perhaps serum osteopontin might be helpful when used along with other biochemical markers of bone formation or resorption when testing for the effectiveness of osteoporosis treatment with one of the FDA-approved medications. And if you are a male who has risk factors for osteoporosis, you could ask your care provider for a serum osteopontin test if that would be more convenient than getting a dual-energy X-ray absorptiometry (DXA) test done. Reported high serum osteopontin levels should then be followed by DXA to rule out osteoporosis.
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