CT检测分析老年女性骨质疏松性髋部骨折患者大腿肌肉脂肪变性与骨密度相关性

Analysis of correlation between thigh muscle fatty degeneration and bone mineral density in elderly female patients with osteoporotic hip fracture by CT

目的探讨老年女性骨质疏松性髋部骨折患者躯体成分和骨密度(BMD)与大腿肌肉脂肪变性的关系。方法选择89例女性骨质疏松性髋部骨折患者,年龄65~86岁,平均年龄74.5岁。采用双能X射线吸收法测定全髋BMD。采用CT测量臀大肌、外展肌、股四头肌和腘绳肌横截面积(CSA)、横截面肌群面积(CSmA)、肌肉衰减系数(MAC)和肌肉间隙脂肪组织(IMAT)。通过CSA值计算标准化IMAT(nIMAT)。检查各测量值之间的相关性,分析股骨粗隆骨折与股骨颈骨折患者肌肉指标之间差异。结果股四头肌MAC值为(53.61±0.96)HU,在4块肌肉中最高;而nIMAT值最低,为(12.12±5.57)%。臀大肌的nIMAT最高,为(35.63±9.29)%。4块肌肉的CSA与BMD、身高、体质量和体质量指数(BMI)呈显著正相关(r=0.412、0.443、0.663、0.347,P<0.01),与年龄呈负相关(r=-0.082,r<0.01)。臀大肌和外展肌MAC与BMD、体质量和BMI呈显著正相关(r臀大肌=0.234、0.305、0.297,r外展肌=0.223、0.364、0.277,P<0.01)。臀大肌、股四头肌和腘绳肌CSmA与BMD、身高、体质量和BMI呈显著正相关(r臀大肌=0.273、0.244、0.415、0.344,r股四头肌=0.274、0.312、0.288、0.163,r腘绳肌=0.204、0.176、0.293、0.184,P<0.01);外展肌CSmA与BMD和体质量呈正相关(r=0.163、0.157,P<0.01)。4块肌肉的nIMAT与体质量和BMI呈显著正相关(r臀大肌=0.145、0.406,r外展肌=0.317、0.304,r股四头肌=0.467、0.433,r腘绳肌=0.355、0.344,P<0.01);大腿中部股四头肌和腘绳肌的nIMAT与BMD呈显著正相关(r=0.174、0.148,P<0.01)。两组患者肌肉大小和脂肪变性程度差异无统计学意义(P>0.05)。结论大腿肌肉大小和脂肪变性程度与体质量呈正相关。BMD与大腿中肌CSA和CSmA、2块臀肌MAC和2块大腿中肌肉脂肪变性呈正相关。股骨粗隆骨折和股骨颈骨折患者股骨肌肉大小及脂肪变性程度无明显差异。

Objective To investigate correlation between body composition/bone mineral density(BMD) and fatty degeneration of thigh muscles in elderly female patients with osteoporotic hip fracture. Methods A total of 89 female osteoporotic hip fracture patients were enrolled, which aged 65-86 years old with mean age of 74.5 years old. The dual energy X-ray absorptiometry was performed to determine total hip BMD. The cross-sectional area(CSA), cross-sectional muscle area(CSmA), muscle attenuation coefficient(MAC), and intramuscular adipose tissue(IMAT) of gluteus maximus, hip abductors, quadriceps and hamstring muscle were measured by CT. The standardized IMAT(nIMAT) was calculated by CSA value. The correlations between those measured values were examined, and differences between muscle index in patients with intertrochanteric fractures and femoral neck fracture were analyzed. Results The quadriceps MAC value was(53.61 ± 0.96) HU, which was the highest in the 4 muscles, while nIMAT value was the lowest[(12.12 ± 5.57) %]. The gluteus maximus had the highest nIMAT at(35.63 ± 9.29) %.The CSA of 4 muscles was significantly positively correlated with BMD, height, weight and BMI( r = 0.412, 0.443, 0.663,0.347, P < 0.01), but negatively correlated with age(r =-0.082, P < 0.01). The MAC of gluteus maximus and abductor were significantly positively correlated with BMD, body mass, and BMI(rgluteus maximus= 0.234, 0.305, 0.297, rhip abductors= 0.223, 0.364,0.277, P < 0.01). The CSmA of gluteus maximus, quadriceps and hamstring were significantly positively correlated with BMD,height, body mass and BMI(rgluteus maximus= 0.273, 0.244, 0.415, 0.344, rquadriceps= 0.274, 0.312, 0.288, 0.163, rhamstrings= 0.204,0.176, 0.293, 0.184, P < 0.01). The abductor CSmA were positively correlated with BMD, body mass(r = 0.163, 0.157, P < 0.01).The nIMAT of 4 muscles was significantly positively correlated with body mass and BMI(rgluteus maximus= 0.145, 0.406, rhip abductors=0.317, 0.304, rquadriceps= 0.467, 0.433, rhamstring muscle= 0.355, 0.344, P < 0.01);There was significantly positive correlation between n IMAT of femoral quadriceps and hamstrings and BMD(r = 0.174, 0.148, P < 0.01). There was no significant difference in muscle size and steatosis between 2 groups(P > 0.05). Conclusion It is demonstrated that muscle size and degree of steatosis are positively correlated with body mass. BMD is positively correlated with CSA and CSmA of thigh muscles, MAC of 2 gluteal muscles, and steatosis of 2 thigh muscles. There is no significant difference in femoral muscle size and degree of steatosis in patients with femoral intertrochanteric fractures and femoral neck fractures.