Independent association of intermuscular adipose tissue with CVD risk factors

Abstract

The metabolic implications of intermuscular adipose tissue (IMAT, adipose tissue visible by MRI within the boundary of the muscle fascia) have been little studied compared to total body adipose tissue (TAT) and visceral adipose tissue (VAT). Whole body magnetic resonance imaging was used to quantify TAT and its components: subcutaneous adipose tissue (SAT), VAT, and IMAT. Fasting serum measures (n=262) of glucose, cholesterol (Chol), high density lipoprotein (HDL), triglycerides (Trig) protein bound glucose (PBG, n=206), and insulin (n=119), were acquired in healthy adult African American (AA, n=78) and Caucasian (Ca, n=109) women (BMI 26.5±5.7 kg/m2; 44.4±16.4 years) and men (39 AA, 62 Ca; BMI 25.6±3.5 kg/m2; 45.6±17.4 years). General linear models were used to identify independent effects of IMAT after covarying for VAT, SAT, race, sex and 2-way interactions. Correlations of IMAT with VAT and SAT ranged between 0.38 and 0.78. Statistically significant independent associations were observed for IMAT with glucose (p<0.001), PBG (p<0.001), and Chol (p=0.005). The association of IMAT to Chol differed by race (p=0.011). TG, HDL and insulin had no independent association with IMAT. The strong independent associations of IMAT with fasting glucose and PBG suggest that IMAT may be related to glucose metabolism, however, IMAT also shows some association to Chol. This study was supported by NIH AG14715, DK42618; RR00645, DK40414; and a contract from the NIA.