Element analysis in femur of diabetic osteoporosis model by SRXRF microprobe.

Diabetes mellitus affects bone metabolism and leads to osteopenia and osteoporosis, but its pathogenic mechanism remains unknown. To address this problem, mineral element of bone was analyzed in experimental diabetic osteoporosis model. Male Wistar rats were randomly divided into streptozotocin (STZ)-induced diabetic group (n=5) and control group (n=5). The experiment lasted 68 days and at the end of the experiment, femoral bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry and element content in femur of animals was determined by synchrotron radiation X-ray fluorescence (SRXRF) microprobe analysis technique. Results showed that femoral BMD in diabetic group was significantly lower than that in control (P<0.01). Relative mineral content of calcium (Ca), phosphorus (P) and zinc (Zn) in diabetic femurs decreased significantly compared to controls. And strontium (Sr) in diabetics reduced 11% (P=0.09). Relative content of sulfur (S) in average was statistically higher (P<0.01) in diabetics than that in controls. But no obvious difference was observed in relative content of chromium (Cr), iron (Fe), copper (Cu), and lead (Pb) between the two groups. Statistical analysis revealed that Ca correlated positively with P (R=0.85 and P<0.001), with Sr (R=0.38 and P<0.05) and with Zn (R=0.37 and P<0.05). Whereas, Zn correlated negatively with S (R=-0.40 and P<0.05). Our results reveal that loss of minerals accounts for the BMD reduction in diabetics.