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.
ABSTRACT
Objective To explore the age related decline in spine muscle volume and fat content in healthy elderly males . Methods Totally 88 males aged 50-79 years were selected from the patients who underwent quantitative CT (QCT) exam of lum‐bar spine .They were subgrouped by 50- <60 years ,60- <70 years and 70-79 years .The muscle fat area ,skeletal muscular area , muscle fat infiltration (MFI) ,abdominal visceral fat volume and subcutaneous fat volume ,abdominal total fat volume were measured by the QCT software .Statistical analysis was performed using intraclass correlation coefficient ,ANOVA with post hoc Bonferroni correction ,Pearson correlation analysis and multiple regression analysis .Results Compared to other two groups ,subjects in 70-79 years subgroup had highest muscle fat area/MFI and least skeletal muscular mass(P<0 .05) .Age‐dependent correlation was found in muscle fat mass(r=0 .381 ,P<0 .05) and MFI(r=0 .358 ,P=0 .001) ,but no obvious correlation was found between age and skeletal muscular mass .Age was the only factor entered into the all three paravertebral muscle composition regression equations , meaning age may had an important influence on paravertebral muscle degeneration .Conclusion Lumbar paravertebral muscle de‐generation in elderly men is correlated with the aging and MFI ,which may play a important role in the normative age‐related decline of skeletal muscle .