HUMAN SUBCUTANEOUS ADIPOSE-TISSUE SHOWS SITE-SPECIFIC DIFFERENCES IN FATTY-ACID COMPOSITION

Adipose tissue was obtained from six women undergoing liposuction twic e at 6-mo intervals. Samples obtained bilaterally from abdomen, inner thigh, and outer thigh had fatty acids quantified by gas chromatograph y. There were no important differences between sides or over time. The saturates 14:0, 16:0, 18:0, and 20:0 were higher in abdominal adipose than in outer thigh (P < 0.002 for all); 16:1 and 18:1 omega 9 were l ower in abdomen vs outer thigh (P < 0.01), whereas 18:1 omega 7 and 20 :1 omega 9 were unchanged. Polyunsaturates 18:2 omega 6, 20:3 omega 6, and 20:4 omega 6 were higher in outer thigh than in abdomen (P < 0.06 ), and inner thigh values were intermediate. These changes in fatty ac id composition resulted in lower mean triglyceride melting points from abdomen to inner thigh to outer thigh, and suggest that temperature m ay influence the selection process determining the variation in adipos e fatty acid composition with anatomical location. Because the site-sp ecific differences included essential fatty acids, selective uptake as well as potential differences in in situ fatty acid modification are indicated.