Data were obtained from the SOTI (Spinal Osteoporosis Therapeutic Intervention) and TROPOS (Treatment Of Peripheral Osteoporosis) studies which randomized participants to receive either strontium ranelate or placebo over three years. The study identified 2346 robust, 2472 intermediate and 264 frail women. At three years, the risk for vertebral fractures was reduced by 30% in the robust, by 45% in the intermediate, and by 58% in the frail patients compared to those assigned to placebo. Risk of vertebral fracture was reduced within one year in all three groups.
This study was published by Rolland Y, Van Kan GA, Gillette-Guyonnet S, Roux C, Boonen S, and Vellas B in Bone 2011;48:332-8.
Skeleton Pirate
Artist: LindaB
Friday, July 22, 2011
Tuesday, July 19, 2011
The Effect Of Bone Strontium On BMD Differs For Different DXA Equipment
Osteoporotic patients treated with strontium ranelate show relatively large increases in bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) due to the replacement of some of the calcium atoms in bone by strontium. A study by Pors Nielsen and colleagues reported that replacement of 1% of calcium atoms by strontium causes a 10% increase in BMD. The ratio of the percentage increase in BMD to the molar percentage of strontium in bone is referred to as the strontium ratio. Theoretically it is expected that the strontium ratio should vary between different manufacturers' DXA equipment depending on the effective photon energy of the device.
In this study the researchers reported theoretical estimates of the strontium ratio for two axial DXA systems and two peripheral DXA devices based on their broad spectrum X-ray emission. The theoretical figures were verified in an experimental study in which the strontium ratio for each device was measured using phantoms containing mixtures of hydroxyapatite and strontium hydrogen-phosphate. The theoretical values of the strontium ratio were 11.0 for the Hologic Discovery, 9.9 for the GE-Lunar Prodigy, 9.1 for the Demetech Calscan, and 8.5 for the Osteometer Dexacare G4. Experimental results were 11.2 for the Discovery, 9.9 for the Prodigy, 8.6 for the Calscan and 6.3 for the Dexacare G4. The results confirm that the effect of bone strontium on BMD measurements is different for different DXA systems. In the future it might be possible to exploit this effect to make a non-invasive estimate of average bone strontium content in groups of patients receiving strontium medication for osteoporosis.
Liao J, Blake GM, McGregor AH, Patel R. Bone. 2010 Nov; 47(5):882-7. Epub 2010 Aug 10
http://www.ncbi.nlm.nih.gov/pubmed/20699129
In this study the researchers reported theoretical estimates of the strontium ratio for two axial DXA systems and two peripheral DXA devices based on their broad spectrum X-ray emission. The theoretical figures were verified in an experimental study in which the strontium ratio for each device was measured using phantoms containing mixtures of hydroxyapatite and strontium hydrogen-phosphate. The theoretical values of the strontium ratio were 11.0 for the Hologic Discovery, 9.9 for the GE-Lunar Prodigy, 9.1 for the Demetech Calscan, and 8.5 for the Osteometer Dexacare G4. Experimental results were 11.2 for the Discovery, 9.9 for the Prodigy, 8.6 for the Calscan and 6.3 for the Dexacare G4. The results confirm that the effect of bone strontium on BMD measurements is different for different DXA systems. In the future it might be possible to exploit this effect to make a non-invasive estimate of average bone strontium content in groups of patients receiving strontium medication for osteoporosis.
Liao J, Blake GM, McGregor AH, Patel R. Bone. 2010 Nov; 47(5):882-7. Epub 2010 Aug 10
http://www.ncbi.nlm.nih.gov/pubmed/20699129
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Wandering Skeleton
Artist: Joel Hoekstra
Osteoporotic Bone
Source: www.mayoclinic.com