RESUMEN
Objective To examine the distribution,volume and glucose-uptake activity of brown adipose tissue (BAT) in adults and investigate their correlations with metabolic indicators.Methods 18F-flurodeoxyglucose (FDG) PET/CT was used to analyze the distribution,volume and glucose-uptake activity of BAT.The clinical and metabolic differences between BAT positive group (n =121) and BAT negative group (n=257) were compared.The influences of metabolic indicators (fast blood glucose (FBG),triglyceride (TG),total cholesterol (TC),high density lipoprotein cholesterol (HDL-C),low density lipoprotein cholesterol (LDL-C),uric acid (UA)) on the distribution,volume and activity of BAT were investigated.Logistic regression analysis,two-sample t test,x2 test and multiple linear regression were used to analyze the data.Results The distribution,volume and glucose-uptake activity of BAT were found to be significantly higher in subjects being tested in colder seasons than those who were tested in warmer seasons:2.91％ (87/2 991) vs 1.68％(34/2018),(433±402) vs (329±298) ml,(212±183) vs (169±145) g (x2=7.66,t values:3.36 and 2.98,all P＜0.05).The female proportion was significantly higher in BAT positive group than that in BAT negative group:68.60％ (83/121) vs 31.91％ (82/257) (x2 =16.10,P＜0.01).The average levels of age,body mass index (BMI),FBG,TG,TC,LDL-C and UA in BAT positive group were significantly low-er than those in BAT negative group:(41.30±10.90) vs (48.70±9.60) years,(21.30±2.40) vs (24.50± 3.10) kg/m2,(4.56±0.74) vs (5.34±1.33) mmol/L,(0.94±0.36) vs (2.06±1.64) mmol/L,(4.42± 0.79) vs (4.88±0.87) mmol/L,(1.99±0.58) vs (3.10±0.77) mmol/L,(285.11±70.00) vs (347.70± 101.10) μmol/L (t values:from-6.25 to-2.94,all P＜0.01).Logistic regression analysis revealed that season,gender,age,BMI,FBG,TG and LDL-C levels were all independent influencing factors of BAT distribution in adults (odds ratios:5.36,2.06,0.95,0.79,0.49,0.23,0.02;P＜0.01 or P＜0.05).Among BAT positive adults,gender and FBG levels were found to be strongly affected by the volume and glucose-uptake activity of BAT (β values:0.28,-0.21,both P＜0.05).Conclusions The distribution,volume and glucose-uptake activity of BAT in adults are associated with multiple metabolic indicators including BMI,levels of glucose,lipid and UA.The distribution of BAT is affected by gender,age,season,BMI,blood glucose,and blood lipids.