Increased postprandial fatty acid trapping in subcutaneous adipose tissue in obese women

The objective of this study was to test the hypothesis that increased fatty acid trapping by subcutaneous adipose tissue might contribute to the devel opment and/or maintenance of obesity. To do so, venoarterial (V-A) gradient s across subcutaneous adipose tissue for triglycerides, glycerol, nonesteri fied fatty acid (NEFA), and acylation-stimulating protein (ASP) were determ ined in eight lean females [body mass index (BMI), 22.2 +/- 0.6] and eight obese females (BMI, 34.4 +/- 3.4). Plasma insulin was also measured at inte rvals throughout this period. Fasting plasma triglyceride was significantly higher in the obese group and postprandial triglyceride was also significa ntly delayed. In contrast, both triglyceride clearance and fatty acid uptak e by subcutaneous adipose tissue were significantly greater in the obese gr oup compared dth the lean group. Fasting insulin did not differ between the groups, but postprandial insulin values were significantly higher in the o bese group, The pattern of ASP release from subcutaneous adipose tissue als o appeared to differ in that it was significantly greater in the early post prandial period (0-90 min) in the obese group versus the lean group and thi s correlated with greater triglyceride clearance during this period. Moreov er, there were strong, positive correlations between BMI and the V-A gradie nt for fasting ASP, the 0- to 90-min area under the curve (AUC) for ASP V-A gradient fasting insulin, and the 0- to 90-min AUC for fatty acid incorpor ation into adipose tissue. Taken together, these data demonstrate that fatt y acid trapping by adipose tissue can be increased even when overall plasma triglyceride clearance is delayed. The postprandial pattern of insulin, in particular, was altered in the obese, although it is certainly possible th at differences in ASP release or response could also contribute to increase d fatty acid trapping in the obese. The data, therefore, suggest that incre ased fatty acid trapping by adipose tissue may be a feature of some forms o f obesity.