The close relationship between postprandial remnant metabolism and insulin resistance

The aim of this study was to investigate the relationship between postprandial remnant-like particle (RLP) metabolism and insulin resistance (IR). The study group consisted of 52 randomly selected subjects. To evaluate postprandial hyperlipidemia, serum lipid and lipoprotein concentrations during fasting and 4h after the fat-loading test were measured in each subject. IR was assessed using the index of homeostasis model assessment (HOMA-R). The subjects were divided into two groups according to the value of HOMA-R: an IR group (n=17) with a HOMA-R value >/=1.73, and a normal (NR) group (n=35) with a HOMA-R value <1.73. Both fasting and postprandial RLP-cholesterol (RLP-C) concentrations were higher in the IR group than in the NR group (6.2+/-2.6 versus 4.1+/-1.7mg/dl fasting value, and 9.7+/-4.0 versus 5.8+/-2.9mg/dl postprandial value). The changes in RLP-C concentration during the fat-loading test were twice as high in the IR group compared with the NR group (3.5+/-2.4 versus 1.6+/-1.6mg/dl, P=0.0022). The HOMA-R correlated significantly with both fasting and postprandial triglyceride (r=0.41 and 0.43, respectively) and RLP-C (r=0.36 and 0.50, respectively) in all subjects. Multiple regression analysis indicate that postprandial RLP-C concentration was an independent predictor of HOMA-R regardless of age, BMI, and other lipid profiles. Thus, postprandial RLP metabolism is closely related to IR. Atherosclerotic proliferation in IR syndrome may be caused by the accumulation of postprandial remnant lipoproteins after the daily fat intake.