| Part Ⅰ Correlation between bone iron content and bone mineraldensity of postmenopausal women with femoral neck fractureObjective: To establish the correlation between bone iron content and bone mineraldensity of postmenopausal women with femoral neck fracture for further study of iron andbone metabolism.Methods:156postmenopausal women suffered from femoral neck fracture aged from56to92years were divided into5groups based upon the stratification of10-year ageintervals(≤60years,61-70years,71-80years,81-90years and≥91years), with an averageage of72.40±8.97years, from June2010to March2013. Blood samples were determinedthe serum iron and bone metabolic markers after overnight fasting. Bone specimens wereobtained from each subject for detecting bone iron contents by inductively coupled plasmamass spectrometry(ICP-MS) and performing Prussian blue iron stain after hip arthroplastysurgery. BMD was measured using dual energy X-ray absorptiometry(DXA) at the hip andlumbar spine from L1to L4. All statistical analyses were performed with SPSS statisticalsoftware.Results: There were significant differences in serum ferritin, bone iron content, serumprocollagen type I N-terminal propeptide(PINP), β-carboxy terminal telopeptide ofcollagen type I (β-CTX) and BMD in the hip and L1-4in all age groups(all P<0.05). BMDin the femur neck and L1-4bothe decreased while serum ferritin and bone iron content increased with age, the peaks of serum ferritin and bone iron content were in the81-90years group, and the average concentration of serum ferritin was235.66μg/L and bone ironwas96.81μg/g. The proportion of serum ferritin over200μg/L was64.1%. The results bymultiple regression analyses showed age together with serum ferritin and bone iron contentcould be negatively associated with BMD in the femur neck. After adjustment for age,weight, BMI and other confounders,the serum ferritin and bone iron content were stillnegatively associated with BMD at proximal femur whereas not significantly associatedwith BMD in the lumbar spine.Conclusion: In postmenopausal women with femoral neck fracture, the serum andbone iron content increased with age. Both of them might be the independent risk factorsfor the decreased BMD in the hip. There was a significant correlation between ironaccumulation and postmenopausal osteoporosis. Part Ⅱ Effects of the change of bone divalent metal elements contentson bone mineral density in postmenopausal womenObjective: To explore the correlations between bone divalent metal elements contents,corresponding serum markers and bone mineral density(BMD) in postmenopausal womenwith femoral neck fracture.Methods: From June2010to March2013,156postmenopausal women with femoralneck fracture, aged from56to92years, were divided into eigth groups based upon thestratification of5-year age intervals (≤60,61-65,66-70,71-75,76-80,81-85,86-90and≥91). Bone specimens were obtained for detecting bone elements(calcium, magnesium, zinc,iron, copper and manganese) contents by inductively coupled plasma-mass spectrometry(ICP-MS) after hip arthroplasty surgery. Meanwhile the data of serum markers and bonemineral density were collected from hospitalized medical records in record room. Multiplelinear regression analysis was use to determine the factors for the change of BMD. Pearson correlation coefficient r was to definite the interaction characteristics. Ki radio was todiscern change in bone elements composition.Results: BMD in the hip and L1-4decreased with age, all patients conformed to thediagnosis of osteopenia or osteoporosis. The contents of bone calcium(Ca),magnesium(Mg), zinc(Zn), copper(Cu) and manganese(Mn) decreased while iron(Fe)increased with age. Serum levels of ferritin had significant differences in all age groups,and there were no differences in serum levels of Ca, P and Mg. Multiple regressionanalyses illustrated age combined with bone Ca and Mg were the independent factors forBMD changes. Importantly, serum ferritin together with bone Fe and Mn could enter themultiple regression models of BMD in the femoral neck (R2=0.565). Additionly, Ca waspositively correlated with Zn, Mg, Cu and Mn but negatively correlated with Fe. The Ki(Fe)(molar Fe/Ca ratio) increased markedly with age (P<0.01).Conclusion: Higher bone iron stores and lower status of other divalent metals,resulted from the interactions in minerals, might be independent risk factors for decreasedhip BMD. In the field of postmenopausal osteoporosis, contents and interactions in bonemetal elements, especially the unique iron accumulation phenomenon, need further studies. |
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