Plasma Lipid Transfer Enzymes in Non-Diabetic Lean and Obese Men and Women

There are considerable differences in the plasma lipid profile between lean and obese individuals and between men and women. Little, however, is known regarding the effects of obesity and sex on the plasma concentration of enzymes involved in intravascular lipid remodeling. Therefore, we measured the immunoreactive protein mass of lipoprotein lipase (LPL), hepatic lipase (HL), cholesterol-ester transfer protein (CETP) and lecithin-cholesterol acyl transferase (LCAT) in fasting plasma samples from 40 lean and 40 obese non-diabetic men and premenopausal women. Women, compared with men, had ~5% lower plasma LCAT (p < 0.041), ~35% greater LPL (p = 0.001) and ~10% greater CETP (p = 0.085) concentrations. Obese, compared with lean individuals of both sexes, had ~30% greater plasma LCAT (p < 0.001), ~20% greater CETP (p < 0.001) and ~20% greater LPL (p = 0.071) concentrations. Plasma HL concentration was not different in lean men and women. Obesity was associated with increased (by ~50%) plasma HL concentration in men (p = 0.018) but not in women; consequently, plasma HL concentration was lower in obese women than obese men (p = 0.009). In addition, there were direct correlations between plasma lipid transfer enzyme concentrations and lipoprotein particle concentrations and sizes. There are considerable differences in basal plasma lipid transfer enzyme concentrations between lean and obese subjects and between men and women, which may be partly responsible for respective differences in the plasma lipid profile.