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 the modulation of high density lipoprotein (HDL) particle size and composition. However, little has been reported concerning the relationships of PLTP with plasma lipoprotein parameters, lipolytic enzymes, body fat distribution, insulin, and glucose in normolipidemic individuals, particularly females. In the present study, 50 normolipidemic healthy premenopausal females were investigated. The relationships between the plasma PLTP activity and selected variables were assessed. PLTP activity was significantly and positively correlated with low density lipoprotein (LDL) cholesterol (rs = 0.53), apoB (rs = 0.44), glucose (rs = 0.40), HDL cholesterol (rs = 0.38), HDL3 cholesterol (rs = 0.37), lipoprotein lipase activity (rs = 0.36), insulin (rs = 0.33), subcutaneous abdominal fat (rs = 0.36), intra-abdominal fat (rs = 0.29), and body mass index (rs = 0.29). HDL2 cholesterol, triglyceride, and hepatic lipase were not significantly related to PLTP activity. As HDL2 can be decreased by hepatic lipase and hepatic lipase is increased in obesity with increasing intra-abdominal fat, the participants were divided into sub-groups of non-obese (n = 35) and obese (n = 15) individuals and the correlation of PLTP with HDL2 cholesterol was re-examined. In the non-obese subjects, HDL2 cholesterol was found to be significantly and positively related to PLTP activity (rs = 0.44). Adjustment of the HDL2 values for the effect of hepatic lipase activity resulted in a significant positive correlation between PLTP and HDL2 (rs = 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 conclude that PLTP-facilitated lipid transfer activity is related to HDL and LDL metabolism, as well as lipoprotein lipase activity, adiposity, and insulin resistance. —Murdoch, S. J., M. C. Carr, J. E. Hokanson, J. D. Brunzell, and J. J. Albers. PLTP activity in premenopausal women: relationship with lipoprotein lipase, HDL, LDL, body fat, and insulin resistance.