PLTP activity in premenopausal women: relationship with lipoprotein lipase, HDL, LDL, body fat, and insulin resistance

Plasma phospholipid transfer protein (PLTP) is thought to play a major role in the facilitated transfer of phospholipids between lipoproteins and in t he modulation of high density lipoprotein (HDL) particle size and compositi on, However, little has been reported concerning the relationships of PLTP with plasma lipoprotein parameters, Lipolytic enzymes, body fat distributio n, insulin, and glucose in normolipidemic individuals, particularly females , In the present study, 50 normolipidemic healthy premenopausal females wer e investigated, The relationships between the plasma PLTP activity and sele cted variables were assessed, PLTP activity was significantly and positivel y correlated with low density lipoprotein (LDL) cholesterol (r(s) = 0.53), apoB (r(s) = 0.44), glucose (r(s) = 0.40), HDL cholesterol (r(s) = 0.38), H DL3 cholesterol (r(s) = 0.37), lipoprotein lipase activity (r(s) = 0.36), i nsulin (r(s) = 0.33), subcutaneous abdominal fat (r(s) = 0.36), intra-abdom inal fat (r(s) = 0.29), and body mass index (r(s) = 0.29), HDL2 cholesterol , triglyceride, and hepatic lipase were not significantly related to PLTP a ctivity. As HDL2 can be decreased by hepatic lipase and hepatic Lipase is i ncreased in obesity with increasing intra-abdominal fat, the participants w ere divided into sub-groups of nonobese (n = 35) and obese (n = 15) individ uals and the correlation of PLTP with HDL2 cholesterol was reexamined. In t he non-obese subjects, HDL2 cholesterol was found to be significantly and p ositively related to PLTP activity (r(s) = 0.44), Adjustment of the HDL2 va lues for the effect of hepatic lipase activity resulted in a significant po sitive correlation between PLTP and HDL2 (r(s) = 0.41), indicating that the strength of the relationship between PLTP activity and HDL2 can be reduced by the opposing effect of hepatic lipase on HDL2 concentrations. We conclu de that PLTP-facilitated lipid transfer activity is related to HDL and LDL metabolism, as well as lipoprotein lipase activity, adiposity, and insulin resistance.