The functional and compositional properties of lipoproteins are altered in patients with metabolic syndrome with increased cholesteryl ester transfer protein activity

Abstract

Abstract.To compare the molecular composition and functional differences at the lipoprotein level, we analyzed individual lipoprotein fractions from male patients with metabolic syndrome (MetS) (n=10) and gender-and age-matched healthy controls (n=14). The MetS group had significantly higher obesity, blood pressure, serum cholesterol, triglyceride (TG), adiponectin, and uric acid levels than the control group, while the serum blood urea nitrogen and creatinine levels of the MetS group were in the normal range. The MetS group had much weaker serum antioxidant ability and were more susceptible to coppermediated low-density lipoprotein (LDL)-oxidation. TG and apoC-III co-accumulated with LDL, high density lipoprotein (HDL) 2 , and HDL 3 in the MetS group. The MetS group had serum amyloid A (SAA)-enriched HDL 2 and HDL 3 , although the serum level of SAA was not higher than in controls. The MetS group had significantly deprived paraoxonase (PON) activity in the serum and HDL, while the MetS group had 38% higher serum cholesteryl ester transfer protein (CETP) activity than that of the control group. Many serum parameters, such as TG, apoC-III, and uric acid, were elevated in the MetS group, and most of these measures were enriched in the LDL and HDL fractions rather than the very low density lipoprotein (VLDL) fraction. The lipid and apolipoprotein composition of HDL was severely altered and its beneficial functions were severely diminished. ApoA-I level was more readily detected in lipoprotein-deficient serum of the MetS group, indicating that the apoA-I exists in a lipid-free state. These results suggest that the MetS group had dysfunctional HDL that enriched TG, apoC-III, CETP, and SAA without antioxidant activity.

HDL subgroups and their paraoxonase‐1 activity in the obese, overweight and normal weight subjects

“…HDL3 PON-1 and non-HDL3 PON-1 activities have been evaluated in the different metabolic diseases related with obesity and discordant results have been reported in these studies. 29,30 No statistically significant differences have been observed between type 2 diabetes mellitus and control group in terms of HDL3…”

“…29 However, similar to our study, Park et al found lower HDL3 PON-1 activity in patients with metabolic syndrome than age matched healthy controls. 30 TA B L E 2 Comparisons of laboratory between groups in the lipoprotein. 11,12 Thus, we think that reduced activity of total PON-1 HDL3 PON-1 and non-HDL3 PON-1 are account for the increased oxidant, inflammatory and atherogenic status in obese.…”