SKELETAL MUSCLE FAT CONTENT ASSESSED BY CT: ASSOCIATION WITH THE INSULIN RESISTANCE SYNDROME IN WOMEN 515

It has been previously proposed that the skeletal muscle fat content, as assessed by computed tomography (CT), was positively correlated with insulin resistance (Simoneau, J.A. et al., FASEB J, 273-278, 1995). In the present study, we have investigated the relationships between the area of mid-thigh muscle with a low CT attenuation level (LAM) (reflecting an increased fat content of the skeletal muscle) and the metabolic profile of a sample of 80 women aged between 25-55 years [BMI: 30.8 ± 8.7 kg/m2 (mean± SD)]. The LAM area was significantly correlated (p< 0.0001) with fat mass (FM; r= 0.82) and visceral adipose tissue area measured at L4-L5(VAT; r= 0.79). The LAM area was also significantly associated with plasma insulin and glucose levels measured in the fasting state and during a 75g oral glucose load (0.37 ≤ r ≤ 0.59; p< 0.001). Moreover, plasma lipid-lipoprotein levels as well as lipoprotein ratios were significantly correlated with the LAM area (-0.47 ≤ r ≤ 0.36; p< 0.05). Finally, LAM area was positively associated with systolic blood pressure (r= 0.37; p< 0.001) but not with diastolic blood pressure measured at rest. These results support the notion that the mid-thigh skeletal muscle fat content assessed by CT is a significant correlate of the features of the insulin resistant-dyslipidemic syndrome.