儿童1型糖尿病骨密度变化及影响因素分析

目的 测定儿童1型糖尿病(T1DM)患者骨密度(BMD),分析探讨骨密度变化的影响因素。方法 选取于2018年1月—2021年6月于我院收治的儿童1型糖尿病患者76例,收集性别、年龄、发病年龄、身高、体重、BMI、病程等基本资料,检测空腹血糖、空腹C肽、糖化血红蛋白(HbA1c)、血碳酸氢根(HCO3-)、血清碱性磷酸酶(ALP),应用双能X线吸收测定法测定骨密度,获取Z值。结果 76例儿童1型糖尿病患者骨密度Z值为-0.93±2.14。HbA1c、病程与骨密度Z值呈负相关,差异具有统计学意义(分别B=-0.334,P<0.001;B=-0.191,P=0.017)。结论 儿童1型糖尿病患者骨密度低于健康儿童,血糖控制不良、病程长是1型糖尿病儿童骨密度减低的危险因素。     

Radiomics for classification of bone mineral loss: A machine learning study

PurposeThe purpose of this study was to develop predictive models to classify osteoporosis, osteopenia and normal patients using radiomics and machine learning approaches.Materials and methodsA total of 147 patients were included in this retrospective single-center study. There were 12 men and 135 women with a mean age of 56.88 ± 10.6 (SD) years (range: 28–87 years). For each patient, seven regions including four lumbar and three femoral including trochanteric, intertrochanteric and neck were segmented on bone mineral densitometry images and 54 texture features were extracted from the regions. The performance of four feature selection methods, including classifier attribute evaluation (CLAE), one rule attribute evaluation (ORAE), gain ratio attribute evaluation (GRAE) and principal components analysis (PRCA) along with four classification methods, including random forest (RF), random committee (RC), K-nearest neighbor (KN) and logit-boost (LB) were evaluated. Four classification categories, including osteopenia vs. normal, osteoporosis vs. normal, osteopenia vs. osteoporosis and osteoporosis + osteopenia vs. osteoporosis were examined for the defined seven regions. The classification model performances were evaluated using the area under the receiver operator characteristic curve (AUC).ResultsThe AUC values ranged from 0.50 to 0.78. The combination of methods RF + CLAE, RF + ORAE and RC + ORAE yielded highest performance (AUC = 0.78) in discriminating between osteoporosis and normal state in the trochanteric region. The combinations of RF + PRCA and LB + PRCA had the highest performance (AUC = 0.76) in discriminating between osteoporosis and normal state in the neck region.ConclusionThe machine learning radiomic approach can be considered as a new method for bone mineral deficiency disease classification using bone mineral densitometry image features.     

症状前期进行性肌营养不良患儿24例病例系列报告

背景：进行性肌营养不良（PMD）中Duchenne型肌营养不良(DMD)和Becker型肌营养不良(BMD)的临床表现、治疗和预后差异明显，目前国内外对症状前期PMD患儿的诊断尚无共识。 目的：探讨婴幼儿时期症状前期PMD患儿的临床特征和实验室检查特点，并探讨血清肌酶水平在DMD和BMD分型诊断中的价值。 设计：病例系列报告。 方法：收集2016年1月至2020年7月江西省儿童医院确诊的症状前期PMD患儿，分析临床特征和实验室检查特点，并以基因检测结果为诊断标准分为DMD组和BMD组，血清肌酶通过ROC曲线分析以约登指数最大值时的取值作为诊断界值，比较不同肌酶的诊断准确性。 主要结局指标：PMD患儿的临床表现、基因结果、血清酶水平（AST、ALT、LTH、CK、CK-MB）。 结果：24例PMD患儿纳入分析，其中DMD组18例，BMD组6例。22例（91.7%）因发现转氨酶升高就诊，2例（8.3%）因亲戚确诊前来就医。PMD患儿CK-MB、CK、LDH、AST和ALT水平均明显升高，DMD组均高于BMD组（除AST外，P均<0.05）。当ALT>224.5 U·L-1、CK>11 069 IU·L-1、CK-Mb>204 IU·L-1、LDH>1 349.5 IU·L-1时为DMD的可能性更高，尤其是LDH>1 349.5 IU·L-1具有高度特异性。 结论：血清肌酶水平增高为 PMD 患儿症状前期的主要表现。LDH＞1 349.5 IU·L-1对诊断DMD具有高度特异性。     

材料和孔隙率对可降解支架内骨形成的影响

目的研究可降解支架植入人体后的骨修复,不同材料和孔隙率对支架内骨形成的影响。方法根据骨折愈合自然反应机理,运用有限元方法,结合支架几何结构,搭建以材料降解曲线和骨重建控制方程为基础的计算耦合模型。通过这一平台,选择5种材料、4种孔隙率的支架代表性体积元进行计算模拟分析,并通过骨密度和支架最大应力反映这一动态过程。结果材料弹性模量对支架内骨组织生长的影响较大,材料弹性模量越小,骨形成量越大,但会对支架的力学性能造成较大影响。较高孔隙率的支架刚度小,能够更好地促进骨组织形成,但同时也会破坏支架的力学稳定性。结论根据不同年龄、性别和部位骨组织的性能需求,为可降解多孔骨支架的材料和孔隙率选择、结构设计以及临床应用提供个性化参考和计算依据。     

抗骨质疏松治疗的最佳他汀类药物及剂量选择的动物试验研究

【】 目的 探索具有最佳抗骨质疏松作用的他汀药物种类和药物剂量,为进一步的研究他汀药物同时发挥抗骨质疏松和调脂作用提供基础。 方法 40只12月龄新西兰白兔通过双侧卵巢切除和泼尼松龙诱导8周建立骨质疏松症模型,随机分为4组：生理盐水(NS)组,瑞舒伐他汀(RSV)组,辛伐他汀(Sim)组,阿仑膦酸钠片(ALN)组。RSV组和Sim组按药物剂量梯度20、40、60、80、100(mg/kg.d)分为5小组。在第0、8、12、24、36周末测量白兔股骨骨密度(BMD)和骨钙素(BGP)、抗酒石酸酸性磷酸酶5b(TRACP-5b)值。 结果 8周末白兔BMD较0周时明显降低(P＜0.05)。RSV组、Sim组比NS组BMD、BGP水平明显升高,TRACP-5b水平显著降低(P＜0.01),并且RSV组与ALN组指标水平接近(P＞0.05)。RSV组内中以60mg/kg.d喂养时,BMD、BGP较其他组明显升高。结论 他汀类药物具有抗骨质疏松的作用,效果接近唑来膦酸;亲水性瑞舒伐他汀比疏水性他汀药物更有作用;并且剂量在60mg/kg.d时效果更好。     

Associations of 25‐Hydroxyvitamin D and 1,25‐Dihydroxyvitamin D With Bone Mineral Density,Bone Mineral Density Change,and Incident Nonvertebral Fracture

Relationships between 1,25‐dihydroxyvitamin D (1,25(OH)₂D) and skeletal outcomes are uncertain. We examined the associations of 1,25(OH)₂D with bone mineral density (BMD), BMD change, and incident non‐vertebral fractures in a cohort of older men and compared them with those of 25‐hydroxyvitamin D (25OHD). The study population included 1000 men (aged 74.6 ± 6.2 years) in the Osteoporotic Fractures in Men (MrOS) study, of which 537 men had longitudinal dual‐energy X‐ray absorptiometry (DXA) data (4.5 years of follow‐up). A case‐cohort design and Cox proportional hazards models were used to test the association between vitamin D metabolite levels and incident nonvertebral and hip fractures. Linear regression models were used to estimate the association between vitamin D measures and baseline BMD and BMD change. Interactions between 25OHD and 1,25(OH)₂D were tested for each outcome. Over an average follow‐up of 5.1 years, 432 men experienced incident nonvertebral fractures, including 81 hip fractures. Higher 25OHD was associated with higher baseline BMD, slower BMD loss, and lower hip fracture risk. Conversely, men with higher 1,25(OH)₂D had lower baseline BMD. 1,25(OH)₂D was not associated with BMD loss or nonvertebral fracture. Compared with higher levels of calcitriol, the risk of hip fracture was higher in men with the lowest 1,25(OH)₂D levels (8.70 to 51.60 pg/mL) after adjustment for baseline hip BMD (hazard ratio [HR] = 1.99, 95% confidence interval [CI] 1.19–3.33). Adjustment of 1,25(OH)₂D data for 25OHD (and vice versa) had little effect on the associations observed but did attenuate the hip fracture association of both vitamin D metabolites. In older men, higher 1,25(OH)₂D was associated with lower baseline BMD but was not related to the rate of bone loss or nonvertebral fracture risk. However, with BMD adjustment, a protective association for hip fracture was found with higher 1,25(OH)₂D. The associations of 25OHD with skeletal outcomes were generally stronger than those for 1,25(OH)₂D. These results do not support the hypothesis that measures of 1,25(OH)₂D improve the ability to predict adverse skeletal outcomes when 25OHD measures are available. © 2015 American Society for Bone and Mineral Research.     

辛伐他汀对正畸牙齿保持阶段骨形成的影响

目的:探讨全身给予辛伐他汀对大鼠正畸牙齿移动后保持阶段骨形成生化指标和骨密度的影响。方法:选用40只雄性Wistar大鼠,随机分成5组:基本对照组、阴性对照组(生理盐水)、低剂量组(2.5mg/kg)、中剂量组(5.0mg/kg)、高剂量组(10.0mg/kg),牵引其上颌第一磨牙向近中移动。实验组在加力装置去除前1d开始,腹膜下注射辛伐他汀;阴性对照组注射生理盐水,1次/d。4周后处死大鼠,取血,检测血清骨钙素(BGP)、碱性磷酸酶(ALP)、钙(Ca)、磷(P),测定上颌第一磨牙区牙槽骨密度(BMD)等。结果:实验组BGP、ALP水平较阴性对照组明显升高(P<0.05),低剂量组升高最明显,随剂量增加,BGP、ALP水平减低;实验组与对照组血清Ca、P无明显差别(P>0.05)。上颌第一磨牙区牙槽骨BMD对照组明显高于其它各组(P<0.05);实验组与阴性对照组比较,低剂量组最高,差异有显著性(P<0.05)。结论:辛伐他汀全身给药能够有效地促进局部牙槽骨骨合成代谢,最适有效剂量为2.5mg/kg。     

The effcct of eel bone powder on bone mineral density in mouse femoral bone

Improvement in bone mineral density (BMD) in the femur after administration of eel bone powder (EBP) was evaluated in ovariectomized (OVX) mice. Female ICR mice were given ovariectomies or sham operations at 9 weeks of age, then housed for 2 weeks during which they were allowed free access to a normal diet. Subsequently, the mice were divided into 3 groups: sham-operated mice fed a normal diet, OVX mice fed a normal diet, and OVX mice fed a diet containing EBP. After the mice in these 3 groups had been housed for 2 months (during which time they were allowed free access to their respective diets), they were dissected and analyzed. The BMD values in the removed femurs were measured by peripheral quantitative computed tomography (pQCT). Femoral total and femoral cancellous BMD values were higher in the EBP-treated group than in the nontreated group. Total BMD: the value in the EBP-treated group was 573 mg/cm³, and that in the non-treated group was 451 mg/cm³ (p<0.05). Cancellous BMD: the value in the EBP-treated group was 242 mg/cm³, and that in the non-treated group was 143 mg/cm³ (p<0.05). However, cortical BMD values did not significantly differ between the EBP-treated group and the non-treated group. Cortical BMD: The value in the EBP-treated group was 1891 mg/cm³, and that in the non-treated group was 1900 mg/cm³. pQCT was used to measure the cortical and cancellous BMD in the long bones. By use of a color conversion technique to display BMD, regional changes in the long bones can be expressed and easily measured. It has been well documented that EBP is effective for improvement or prevention of BMD reduction associated with OVX.     

北京市中老年女性月经及身体成分与骨密度的相关性研究

目的调查北京市中老年女性年龄、月经和身体成分特征,分析其与骨密度的关系以及对骨密度的影响。方法招募45～80岁女性384名,调查受试者月经状况,包括初潮年龄、绝经年龄和绝经年限;测试受试者腰椎、左股骨颈、左髋以及全身骨密度,并测试全身脂肪和肌肉含量,由此计算脂肪含量指数(fat mass index,FMI)、肌肉含量指数(lean mass index,LMI)和四肢骨骼质量指数(appendicular skeletal muscle mass index,ASMI)。采用Pearson相关和多元逐步回归模型分析各因素与骨密度的关系。结果相关性结果显示,年龄、绝经年限、初潮年龄与骨密度呈显著负相关,绝经年龄、LMI、FMI和ASMI与骨密度呈显著正相关。多元逐步回归分析结果显示,绝经年限与各部位骨密度均呈显著负相关,ASMI与各部位骨密度均呈显著正相关,FMI仅与全髋和全身骨密度具有显著相关性,初潮年龄和绝经年龄仅与腰椎和全身骨密度具有显著相关性。结论绝经年限是中老年女性骨密度的独立危险因素,而ASMI则为独立保护因素,绝经年龄、初潮年龄以及FMI对中老年女性骨密度的影响存在部位差异性。