Mass concentration of plasma phospholipid transfer protein in normolipidemic, type IIa hyperlipidemic, type IIb hyperlipidemic, and non-insulin-dependent diabetic subjects as measured by a specific ELISA

Mean plasma phospholipid transfer protein (PUTP) concentrations were measur ed for the first time by using a competitive enzyme-linked immunosorbent as say. PLTP mass levels and phospholipid transfer activity values, which were significantly correlated among normolipidemic plasma samples (r=0.787, P<0 .0001), did not differ between normolipidemic subjects (3.95+/-1.04 mg/L an d 575+/-81 nmol.mL(-1).h(-1), respectively; n = 30), type IIa hyperlipidemi c patients (4.06+/-0.84 mg/L and 571+/-43 nmol.mL(-1).h(-1), respectively; n=36), and type IIb hyperlipidemic patients (3.90+/-0.79 mg/L and 575+/-38 nmol.mL(-1).h(-1), respectively; n = 33). No significant correlations with plasma lipid parameters were observed among the various study groups. In co ntrast, plasma concentrations of the related cholesteryl ester transfer pro tein (CETP) were higher in type IIa and type IIb patients than in normolipi demic controls, and significant, positive correlations with total and low d ensity lipoprotein cholesterol levels were noted. Interestingly, plasma PLT P mass concentration and plasma phospholipid transfer activity were signifi cantly higher in patients with non-insulin-dependent diabetes mellitus (n=5 0) than in normolipidemic controls (6.76+/-1.93 versus 3.95+/-1.04 mg/L, P< 0.0001; and 685+/-75 versus 575+/-81 nmol.mL(-1).h(-1), P<0.0001, respectiv ely). In contrast, CETP levels did not differ significantly between the 2 g roups. Among non-insulin-dependent diabetes mellitus patients, PLTP levels were positively correlated with fasting glycemia and glycohemoglobin levels (r=0.341, P=0.0220; and r=0.382, P=0.0097, respectively) but not with plas ma lipid parameters. It is proposed that plasma PLTP mass levels are relate d to glucose metabolism rather than to lipid metabolism.