定量CT分析年龄、腹部脂肪与骨密度的关系

目的采用定量CT(QCT)探讨腹部脂肪及骨密度(BMD)随年龄变化的规律及腹内脂肪(VAT)与BMD的相关性。资料与方法选取行低剂量胸部CT联合QCT检查的健康体检者2442例,其中男1522例,女920例,根据年龄分为5个年龄段:30~39、40~49、50~59、60~69、70~90岁。采用QCT测量L2中心层面腹部总脂肪(TAT)、VAT、皮下脂肪(SAT)及腰椎BMD。分析不同性别各年龄段间TAT、VAT、SAT、BMD的差异及TAT、VAT、SAT与BMD的相关性。结果50岁以上男性各年龄段TAT、VAT高于30~39岁男性(P均<0.01),而SAT低于30~39岁男性(P均<0.05)。50岁以上女性各年龄段TAT、VAT、SAT高于30~39岁女性(P均<0.001)。50岁以上男性及女性各年龄段间TAT、VAT、SAT比较,差异均无统计学意义(P均>0.05),40~49、50~59岁年龄段分别较上一年龄段VAT明显增多(P均<0.01),BMD随年龄增长逐渐减低(P均<0.001)。多元逐步回归分析显示,VAT是女性BMD的独立影响因素(β=-0.089,P=0.007),TAT、SAT不是BMD的独立影响因素(P均>0.05)。结论腹部脂肪和BMD随年龄发生变化,男性和女性均在40~59岁出现VAT明显增多。VAT可能是女性BMD的独立负性影响因素。

Relationship Among Age,Abdominal Fat and Bone Mineral Density by Quantitative CT

Purpose To explore the changes of abdominal fat and bone mineral density(BMD)with age and the correlation between visceral adipose tissue(VAT)and BMD by quantitative CT(QCT).Materials and Methods 2442 healthy individuals underwent lowdose chest CT and QCT were enrolled,including 1522 males and 920 females,who were divided into five age-groups(30-39,40-49,50-59,60-69,70-90 years old)according to age.Total adipose tissue(TAT),VAT and subcutaneous adipose tissue(SAT)at central L2 level and lumber BMD were measured by QCT.The differences of TAT,VAT,SAT and BMD among age-groups within each gender and the correlation between TAT,VAT,SAT and BMD were analyzed.Results The TAT and VAT of age-groups over 50 years old were higher than 30-39 age-group(all P<0.01),and SAT were lower than 30-39 age-group in male(all P<0.05).The TAT,VAT and SAT of agegroups over 50 years old were higher than 30-39 age-group in female(all P<0.001).There were no significant differences of TAT,VAT and SAT among age-groups of both male and female subjects over 50 years old(all P>0.05);the VAT of 40-49 and 50-59 age-groups increased significantly,compared with the previous age-group,respectively(all P<0.01),and BMD decreased gradually with age(P<0.001).Multiple stepwise regression analysis showed that VAT was an independent impact factor of BMD in female(β=-0.089,P=0.007),while TAT and SAT were not independent impact factors of BMD(P>0.05).Conclusion Abdominal fat and BMD change with age,and the VAT increases significantly in 40-59 years-old males and females.The VAT may be an independent and negative impact factor of BMD in female.