ABSTRACT
Objective To explore the correlation between the posterior vertebral muscle group aging degeneration and body mass index (BMI) in normal middle-aged and elderly women.Methods One hundred and fifteen women(48-75 years old) were divided into the middle-aged group (＜60 years old) and elderly group (≥60 years old).The muscle area of posterior vertebral muscle group and fat area at lumbar levels L3 were measured by quantitative computed tomography (QCT).The muscle fat infiltration (MFI),e.g.fat area/(muscle area + fat area),was calculated.The differences between the two groups were compared by using independent-samples t test.The correlation and linear regression analysis were used for analyzing the correlations between the muscle area,fat area and MFI with age and BMI.Results The BMI had no statistical difference between the two groups (P＞0.05),while the muscle area of posterior vertebral muscle group,fat area and MFI had statistical difference (t=2.182,-1.997,-2.604,P=0.031,0.048,0.010);the correlation and linear regression analysis showed that controlling the body height,body mass factor and age were positively correlated with the fat area of posterior vertebral muscle group and MFI(r=0.275,0.320,t=2.915,3.445,P=0.004,0.001),while had no obvious correlation with the muscle area(r=-1.109,P =0.270);controlling age factor and BMI were positively correlated with the fat area of posterior vertebral muscle group and MFI(r=0.361,0.307,t=3.945,3.277,P≤0.001),while had no obvious correlation with the muscle area(t=1.653,P=0.101).Conclusion In middle-aged and elderly women,the fat content of posterior vertebral muscle group is increased with the age increase.In evaluating the degeneration,especially greater body mass,the fat content of muscles and their proportion have more significance than the muscle area.