M. Carantoni et al., RELATIONSHIP BETWEEN INSULIN-RESISTANCE AND PARTIALLY OXIDIZED LDL PARTICLES IN HEALTHY, NONDIABETIC VOLUNTEERS, Arteriosclerosis, thrombosis, and vascular biology, 18(5), 1998, pp. 762-767
This study was performed in 36 healthy volunteers to define the relati
onship between plasma concentrations of partially oxidized low density
lipoprotein (poxLDL), plasma glucose and insulin responses to oral gl
ucose, and steady-state plasma glucose (SSPG) concentrations after a 1
80-minute infusion of somatostatin, insulin, and glucose. The concentr
ation of poxLDL was estimated by determining the amount of conjugated
dienes formed during in vitro LDL oxidation in the presence or absence
of alanine, Under these conditions, the greater the in vitro antioxid
ant effect of alanine, the lower the amount of poxLDL that was present
in plasma. The results demonstrated that plasma poxLDL concentration
was significantly correlated with plasma glucose (r=.53, P<.001) and i
nsulin (r=.43, P<.01) responses, SSPG concentrations (r=.53, P<.001),
and plasma triglyceride (r=.42, P<.01) and HDL cholesterol (r=-.50, P<
.002) concentrations. Furthermore, these relationships persisted when
the data were corrected for differences in age, sex, body mass index,
and the ratio of waist to hip girth. Of note, there was no correlation
between poxLDL and LDL cholesterol concentration. When SSPG was enter
ed along with age, sex, body mass index, and waist-to-hip ratio in a m
ultiple regression model, SSPG alone was a significant prediction of p
oxLDL (r(2)=.37, P<.02). The addition of plasma glucose and insulin re
sponses and triglyceride and HDL cholesterol concentrations increased
the r(2) to only .47. These results show that the amount of poxLDL in
plasma is significantly correlated with insulin resistance (ie, SSPG)
and its metabolic consequences.