Abstract P288: Associations between Ectopic Fat Depots, Cardiovascular Risk Factors and Subclinical Atherosclerosis Vary by Location of Ectopic Fat in Middle-aged Men: The ERA JUMP Study
Objective: Persons of similar body size may vary widely in their risk of CVD, suggesting that factors other than overall adiposity may contribute to adiposity related CVD risk. Ectopic fat in lean tissue such as liver, muscle and heart, is associated with CVD risk. The degree to which these fat depots may impact CVD risk beyond overall and central adiposity is not fully understood. We examined the associations of liver fat, psoas muscle fat, heart fat (pericardial (PAT) and epicardial (EAT) adipose tissue) with traditional CVD risk factors and subclinical atherosclerosis, independent of overall adiposity (BMI) or central adiposity (waist circumference (WC)), in middle-aged men.
Design: We evaluated 1055 men (age: 45.2±2.4 years; White: 26.9%, Black: 7.8%, Japanese American: 22.7%, Japanese: 24.8%, Korean 17.8%) from the electron-beam computed tomography and risk factor assessment in Japanese and US men in the post-World War II birth cohort study (ERA JUMP), who were free of CVD. Computed tomography was used to measure ectopic fat in liver (liver/spleen attenuation ratio), psoas muscle (CT attenuation value) and heart (PAT and EAT volumes). Partial Spearman correlation coefficients were estimated between ectopic fat depots and each of SBP, triglycerides, LDL-C, HDL-C, insulin resistance: HOMA index, C-reactive protein (CRP), carotid intima media thickness (cIMT), adventitial diameter (AD), coronary (CAC) and aortic calcification (AC), and carotid femoral pulse wave velocity (cfPWV). Initial models were adjusted for age, race, medication use, smoking and alcohol drinking, followed by further adjustment for BMI or WC.
Results: Independent of covariates and BMI or WC, all fat depots were significantly associated with higher CRP; correlations with liver fat were the strongest. Except for muscle fat, all fat depots were significantly associated with higher HOMA index; correlations with EAT and PAT were the strongest. Liver fat, EAT and PAT were significantly associated with higher SBP, LDL-C (except for PAT) and triglycerides and lower HDL-C; correlations with liver fat were the strongest. Muscle fat was only associated with higher LDL-C. For measures of subclinical atherosclerosis, independent of covariates and BMI, all fat depots were significantly associated with higher cfPWV; correlations with PAT were the strongest. Additionally, muscle fat was significantly associated with AD and CAC, while EAT was significantly associated with AC. Results were similar adjusting for WC, except EAT and muscle fat were no longer correlated with cfPWV, and EAT became significantly associated with CAC but not with AC.
Conclusions: Associations between ectopic fat depots, CVD risk factors and subclinical atherosclerosis vary by ectopic fat location. Ectopic fat depots could be useful markers of increased CVD and subclinical atherosclerosis risk beyond overall and central adiposity in middle-aged men.
- © 2013 by American Heart Association, Inc.