Does Strontium Change the Quality of Bone Apatite Crystals?

The potential effect of strontium (Sr) on bone apatite (bone mineral) crystals was investigated in paired biopsies of osteoporotic women treated with either strontium ranelate (SrRan) or a placebo for 36 months. In ten paired biopsies, crystallinity, apparent length and width/thickness of crystals, interplanar distances, and lattice parameters of unit cells were assessed by X-ray diffraction and selected area electron diffraction. None of these parameters, reflecting crystal and unit cell characteristics, was influenced by the presence of Sr. All of the parameters were similar in SrRan and placebo groups after 36 months of treatment. The mean rate of substitutions of calcium by Sr ions was 4.5 %. Overall, the quality of bone apatite crystals was maintained after 36 months of treatment with SrRan. Results of this study were published on March, 2013, in Osteoporosis International.

http://www.ncbi.nlm.nih.gov/pubmed/23108780

 

 

Protein Believed to Cause Postmenopausal Osteoporosis

Researchers have identified a protein that likely causes osteoporosis in women after menopause. In experiments on mice, the research team from Tokyo’s Keio University School of Medicine and other institutions found that a decrease in the secretion of estrogen enhances the function of HIF1 alpha protein. Once the amount of estrogen secreted by the ovaries begins to decline around the time of menopause, HIF1 alpha protein in osteoclasts increases.

Normal mice after menopause showed decreased femoral bone density compared with premenopausal levels, but mice whose genes were manipulated so as not to produce the HIF1 alpha protein did not show a decline of femoral bone density even after menopause. Moreover, a substance to inhibit the function of the HIF1 alpha protein that was given to postmenopausal mice led to an increase of bone density compared with premenopausal levels. The discovery is expected to lead to the development of an effective medicine to prevent osteoporosis.

The study is to be published in the online edition of the Proceedings of the U.S. National Academy of Science.

http://ajw.asahi.com/article/behind_news/social_affairs/AJ201309100058

 

 

From Osteoporosis to Osteopenia with Strontium Citrate

After five and a half years of taking strontium citrate (680 mg strontium daily), I went from osteoporosis to osteopenia. I was probably at the osteopenia stage much earlier, but I waited four years between my previous DEXA scan, which showed improvement at all sites but still left me with osteoporosis, and this one. My density increased 34% in the lumbar spine and 55% in the left hip! These numbers are phenomenal! Even if up to 50% of the change in BMD were attributed to the effect of strontium, which has a higher atomic number than calcium and will affect DEXA measurements, the numbers would still be great. My BMD is now 0.871 g/cm2 at the spine from L1- L4 (T-score -1.6), 0.692 g/cm2 at the left femoral neck (-1.4 T-score), and 0.775 g/cm2 at the left total hip (-1.4 T-score). Osteopenia is defined as T-scores < -1.0 and -2.5.

Non-Invasive Measurement of Bone Strontium Levels

Many of you have probably read that the only way to measure the amount of strontium in bone is to do a bone biopsy. That is no longer true, at least not in a research setting. A case study published last year in Bone used an in vivo X-ray fluorescence (IVXRF) I-125 based system to measure bone strontium levels non-invasively in an osteoporotic female volunteer before and after she began taking strontium citrate supplements (680 mg Sr/day).

Thirty-minute measurements were taken at the finger and ankle bone sites, representing primarily cortical and trabecular bone, respectively. Baseline natural strontium levels were obtained followed by a 24h measurement of first intake of strontium citrate supplements (680 mg Sr/day). The baseline levels of strontium (prior to supplementation) were 0.38 ± 0.05 and 0.39 ± 0.10 for the finger and ankle, respectively. After 24 hrs the levels were 0.62 ± 0.14 and 0.45 ± 0.12 for the finger and ankle, respectively. By 120 h, the increase was statistically significant at 0.68 ± 0.07 and 0.93 ± 0.05, respectively. Further increases occurred within an interval of 90-180 days, with the most recent, after 800 days, at the finger and ankle being 7 and 15 times higher than the initial baseline reading.

The results show bone strontium incorporation and retention follow a pattern and suggest strontium levels, at least in the ankle, do not plateau within two to three years and will continue to increase over time, as an individual takes strontium supplements. The ability of this IVXRF system to monitor and measure bone strontium levels over time provides a useful diagnostic tool to help gain insight into strontium bone kinetics.

 

 

Healing Fractures with Strontium Ranelate

Age and bone quality are the two most important factors influencing the fracture healing process. Cellular and molecular alterations in elderly patients may lead to pseudarthrosis (nonunion), i.e., a fracture that has not united in the stipulated time in which such fractures usually unite and has no chance of union without intervention. In the same way, in altered bone metabolism conditions, such as osteoporosis, physiological phases of fracture healing are impaired.

Two women with fractures that would not heal were started on strontium ranelate (2g/day), calcium (1200 mg/day), and vitamin D (800 IU/day). Patient B.G. was a 57-year-old Caucasian woman with osteopenia and a fracture of the right distal radius and ulna. Patient S.L. was a 59-year-old Caucasian woman with osteoporosis and a fracture of the base of the fifth metatarsal in the left foot. Their case studies showed healing of fractures in a short period of time after drug and supplement intervention.

Read more about these fascinating studies, which contain figures of several radiographs and a CT scan, at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2898010/

EMA Confirms Recommendations to Restrict Strontium Ranelate

The European Medicines Agency (EMA) has confirmed the recommendations to restrict the use of strontium ranelate (Protelos/Osseor, Servier) due to concerns about the risk of adverse cardiac events. The EMA's Pharmacovigilance Risk Assessment Committee (PRAC) recommended the restrictions earlier this month, and the Committee for Medicinal Products for Human Use (CHMP) has now endorsed these following its meeting of April 22-25, 2013. The CHMP opinion will be sent to the European Commission, the executive branch of the European Union, which will issue a legally binding decision.