The relationship between
low-density lipoprotein (
LDL) peak particle diameter and
insulin sensitivity,
very-low-density lipoprotein (VLDL) +
intermediate-density lipoprotein (
LDL) triglyceride,
cholesterol, and
apoprotein B, postprandial
lipemia, and
LDL +
high-density lipoprotein (
HDL) triglyceride was assessed. The subjects were 101 healthy males aged 15 to 45 years. Sixty-one subjects (60.4%) were offspring of a parent with
coronary artery disease before age 60, and 40 subjects (39.6%) had no parental history of
coronary artery disease.
LDL peak particle diameter was measured following
polyacrylamide gradient gel electrophoresis. An
insulin sensitivity index (Si) was determined from a frequently sampled intravenous
glucose tolerance test using a minimal modeling method. A fat tolerance test was performed with a test meal containing 70 g/m2 fat, with
triglyceride concentrations measured hourly for 12 hours.
LDL peak particle diameter was significantly correlated with body mass index (BMI) (r = -.282, P < .01), waist to hip ratio (r = -.291, P < .01), fasting
triglyceride (logarithmically [log] transformed) (r = -.566, P < .001), area under the postprandial
triglyceride curve (log transformed) (r = -.562, P < .001), VLDL + IDL
triglyceride (log transformed) (r = -.462, P < .001), VLDL +
IDL cholesterol (log transformed) (r = -.477, P < .001), VLDL + IDL
apoprotein B (log transformed) (r = -.321, P < .001),
LDL +
HDL triglyceride (log transformed) (r = .583, P < .001), and
HDL cholesterol (r = .347, P < .001), but there was no significant correlation with Si. Using stepwise regression analysis,
LDL +
HDL triglyceride showed the strongest relationship to
LDL peak particle diameter, accounting for 34% of the variation in size. Si was not an independent predictor of
LDL particle size. In conclusion,
insulin sensitivity appears to have little influence on
LDL particle size. The importance of
LDL +
HDL triglyceride should be considered a preliminary finding warranting verification in this and other populations.