生酮饮食导致小鼠骨质疏松的显微骨结构和生物力学研究  

Bone micro-structural and biomechanical study of osteoporosis induced by ketogenic diet in mice

作　　者：吴秀华[1] 王晓萌[1] 黄志平[1] 刘俊豪[1] 黄祖成[1] 孔刚刚 朱青安[1] 

机构地区：[1]南方医科大学南方医院脊柱骨科,广东广州510515

出　　处：《中国骨质疏松杂志》2017年第3期322-327,共6页Chinese Journal of Osteoporosis

基　　金：国家自然科学基金(81472084);广东省自然科学基金(2015A030313276)

摘　　要：目的探讨酮体代谢小鼠骨结构和生物力学改变,以及所导致的小鼠骨质疏松。方法 10只8周龄的C57小鼠随机分为生酮饮食(KD)组和正常饮食(SD)组,每组5只,喂养3个月。生酮饮食的碳水化合物与脂肪的比例为1∶4。每两周监测小鼠体重、血糖和血酮。采用显微CT测量小鼠股骨远端松质骨的骨微结构和中段皮质骨的骨结构参数,厚度和面积。采用脱钙后的石蜡切片HE染色观察骨小梁分布。采用三点弯曲实验评价胫骨力学强度。结果 KD组血酮水平为0.8 mmol/L,明显高于SD组(0.2 mmol/L,P<0.05)。KD组股骨远端松质骨的骨密度、骨体积分数和骨小梁连接密度分别为(49.5±3.6)mg HA/ccm、(4.1±0.5)%和(12.4±1.9)mm-3,而SD组分别为(69.1±4.0)mg HA/ccm、(6.4±1.0)%和(27.4±9.7)mm-3,两组间的差异均有统计学意义(P<0.05)。两组间的骨小梁数目和厚度的差异没有统计学意义(P>0.05)。KD组股骨中段皮质骨平均横截面积为(0.69±0.08)mm2,显著小于SD组(0.80±0.06)mm2。KD组胫骨三点弯曲的最大力、刚度和最大吸收能量分别为(7.3±0.7)N、(25.1±2.4)N/mm、(1.4±0.4)m J,显著小于SD组[(10.1±0.6)N、(33.4±2.9)N/mm、(2.3±0.5)m J]。结论本研究表明生酮饮食降低松质骨的骨密度、骨体积分数、骨小梁的连接程度,减少皮质骨的横截面积,降低骨力学强度,导致骨质疏松。Objective To investigate bone microstructural and biomechanical changes following ketogenic diets in mice,and to study osteoporosis induced by the ketogenic diets.Methods Ten C57 mice（ 8-week-in-age） were randomly divided into the ketogenic diet（ KD） group and the standard diet（ SD） group.The KD is a formula food with 4 ∶ 1 ratio of fat to carbohydrate and protein.Body weight,blood glucose and blood ketone levels were tested every 2 weeks for 3 months.Bone micro-structures at the distal metaphysis and the middle shaft of femur, including bone mineral density, bone volume/tissue volume, trabecular thickness,trabecular number,trabecular separation,cortical bone thickness and cortical bone cross sectional area,were measured using a micro CT.The histologic observation of the distal femur was performed on HE staining images.Biomechanical evaluation of tibia was conducted using a three-point-bending test.Results Blood ketone in the KD group was significantly higher than that of the SD group（ 0.8 mmol/L vs.0.2 mmol/L,P〈0.05）.Bone density,bone volume fraction and trabeculae connection density at the distal femur in the KD group were 49.5 ± 3.6 mg HA/ccm,4.1 ± 0.5% and 12.4 ± 1.9 mm- 3,respectively,which were significantly lower than those in the SD group（ 69.1 ± 4.0 mg HA/ccm,6.4 ± 1.0% and 27.4 ± 9.7 mm- 3,respectively,all P〈0.05）.Crosssectional bone area at the femoral shaft was 0.69 ± 0.08 mm2 in the KD group,and significantly smaller than the area in the SD group（ 0.80 ± 0.06 mm2,P〈0.05）.The maximum force,stiffness and maximum absorption energy of tibia in the KD group was7.3 ± 0.7 N、25.1 ± 2.4 N/mm and 1.4 ± 0.4 m J,which were significantly lower than those in the SD group（ 10.1 ± 0.6 N,33.4± 2.9 N/mm and 2.3 ± 0.5 m J,P〈0.05）.Conclusion The ketogenic diet led to osteoporosis in mice by attenuating microstructure of trabecular bones,decreasing the cross-sectional area of cortical bones,and weakening the mechanical strength of bones.

关 键 词：生酮饮食 骨质疏松 骨微结构 生物力学强度 

分 类 号：R-332[医药卫生]