Role of hepatic-triglyceride lipase activity in the association between intra-abdominal fat and plasma HDL cholesterol in obese women.

Intra-abdominal fat content is an important variable in the association between regional body fat distribution and plasma high density lipoprotein (HDL) cholesterol levels. In the present study, we report on the role of plasma postheparin lipases as well as abdominal and femoral adipose tissue lipoprotein lipase activities in the association between body fat distribution and plasma lipoprotein levels. Postheparin plasma lipoprotein lipase (LPL), hepatic-triglyceride lipase (H-TGL), abdominal and femoral adipose tissue (AT)-LPL activities and plasma lipoprotein levels were measured after an overnight fast in a sample of 16 obese women (ages 36.0 +/- 6.1 years [mean +/- SD], percent body fat 46% +/- 6%). Computed axial tomography was used to assess body fat distribution. Plasma postheparin LPL activity was neither correlated with total adiposity nor with the level of intra-abdominal fat. Intra-abdominal fat deposition was, however, positively correlated with H-TGL activity (r = 0.66, p less than 0.005). Furthermore, covariance analysis showed that the association between intra-abdominal fat and H-TGL was independent from total adiposity. Plasma postheparin LPL and abdominal AT-LPL activities showed no significant correlation with plasma lipoprotein levels, whereas femoral AT-LPL activity was positively correlated with the HDL2 cholesterol/HDL3 cholesterol ratio (r = 0.51, p less than 0.05). H-TGL activity was, however, negatively correlated with HDL2 cholesterol (r = -0.60, p less than 0.05), but not with HDL3 cholesterol (r = -0.28, NS). These results suggest that the high H-TGL activity in obese women with excess deep abdominal fat could be responsible for the reduction in plasma HDL2 cholesterol levels.(ABSTRACT TRUNCATED AT 250 WORDS)