Low density lipoprotein particle size and risk factors of insulin resistance syndrome

The present study aimed to examine the association between low density lipo protein (LDL) particle size and glucose and insulin variables and with othe r risk factors that have been related to insulin resistance syndrome. LDL p article size was determined in two groups of subjects who participated in t he first examination of the Jerusalem Diabetes Study and who were invited t o be re-examined after 8-10 years. The first group were non-diabetic subjec ts who were found to have at the first examination high insulin levels (abo ve the sex and age specific 90th percentile of the 2 h post-glucose load in sulin distribution). The second group was a random sample of individuals wh o had normal insulin and glucose levels at baseline. Sex-: Age- and body ma ss index (BMI) mean adjusted LDL-cholesterol (C), triglyceride (TG) and hig h density lipoprotein cholesterol (HDL-C) levels were significantly differe nt among the LDL subclass groups. Fasting glucose levels and hemoglobin A,, did not differ statistically by LDL subclasses. Fasting and 2-h post load insulin levels were significantly higher in persons with LDL subclasses III and IV (small LDL), intermediate in those with LDL subclass II, and lowest in those with LDL subclass I (large LDL). Insulin resistance had an effect on the association between lipids, lipoproteins and LDL particle size. Mul tivariate analyses indicated that LDL-C, HDL-C and TG were independently as sociated with LDL particle size variability. The addition of 'insulin resis tance' or insulin and glucose levels had no independent effects on LDL part icle size. In conclusion, an association of LDL particle size with the clus ter of risk factors that characterize the insulin resistance syndrome has b een demonstrated. The association of 'insulin resistance' and LDL particle diameter, however, is not mediated directly through the level of insulinemi a but via alterations in lipid metabolism. (C) 2000 Elsevier Science Irelan d Ltd. All rights reserved.