BODY-FAT DISTRIBUTION, INSULIN-MEDIATED SUPPRESSION OF NONESTERIFIED FATTY-ACIDS AND PLASMA TRIGLYCERIDES IN OBESE SUBJECTS

Triglyceride levels and free fatty acid metabolism are influenced by b ody fat distribution. To test whether the pattern of fat distribution in obese subjects results in distinct insulin mediated suppression of non-esterified fatty acids which could account for differences in plas ma triglycerides, we studied 59 obese subjects who were classified acc ording to waist-to-hip ratio. Mon-esterified fatty acids and insulin r esponse to a 75 g oral glucose tolerance test were higher in abdominal obesity. Total non-esterified fatty acids response, after adjustment for sex, showed a positive association with waist-to hip ratio (r = 0. 292; p < 0.05). The abdominal obese group had higher fasting triglycer ides (1.74 +/- 0.83 versus 1.11 +/- 0.71 mmol/L; p = 0.003) and lower glucose/insulin ratio (5.2 +/- 2.3 versus 7.1 +/- 2.4; p = 0.003). Ste pwise multiple regression analysis showed that triglyceride levels are explained by fasting and 120 min non-esterified fatty acids and by gl ucose/insulin ratio. We conclude that abdominal obesity is associated with a higher resistance to insulin mediated suppression of non-esteri fied fatty acids in obese subjects. Variation of triglyceride concentr ations in obesity is dependent on both fasting and 120 min non-esterif ied fatty acids as well as on insulin sensitivity to glucose utilizati on.