Association Of Small Low-Density Lipoprotein Particles And The TaqIB Polymorphism Of Cholesteryl Ester Transfer Protein With Coronary Heart Disease

Objective To study the relationship between small low-density lipoprotein(sLDL) particles and the TaqlB polymorphism of cholesteryl ester transfer protein(CETP) in coronary heart disease.Methods We addressed this issue in a case-control study where 234 subjects with angiographically documented coronary artery disease and 163 subjects without CHD ( CHD was excluded by coronarography). The sLDL levels were detected by PAGE. Restriction fragment length polymorphism (RFLP) analysis was performed to screen the CETP TaqlB polymorphism.Results (1) mean plasma sLDL levels were significantly higher in patients with coronary heart disease than that in controls (58.48 + 5.21% vs 55.10 + 5.60%,p<0.001).There was a strong positive correlation between small LDL percentage and coronary artery stenosis score (r=0.452,P<0.001). Logistic regression analysis showed that small LDL percentage correlated with the risk of CHD. After adjustment for the other risk factors, small LDL was still an independent risk factor of CHD ( r=0.4211, P<0.001). (2) Plasma lipids and lipoproteins were evaluated in the different CETP TaqlB genotype groups, the levels of HDL were associated with CETP polymorphism (P<0.01). Subjects carrying the B₁B₁ genotype showedsignificantly lower HDL-C levels compared with those carrying the 6162 and 6262 genotype ( B,B, 1.23 ?.23 mmol/1, BiB2 1.32?.34 mmol/1, B2B2 1.40?.23 mmol/1; F=6.49, P<0.01). Specifically, mean plasma TG levels were high in CHD patients, a lower sLDL concentration was noted in 8282 genotype than B₁B₁ and BiB2 genotype( B,B, 59.67 + 5.46%, B₁B2 58.04?.01%, B2B2 55.93+4.88%; F=3.83, P<0.05). (3) No significant difference was found in the frequencies of CETP TaqlB genotype and alleles between controls and CHD patients ( x 2=0.77, P>0.05; x 2=0.03, P>0.05 respectively).Conclusion (1) The level of sLDL was an independent risk factor of CHD. There was relationship between small LDL and the severity of CHD. (2) There was relationship between the TaqlB mutation and high HDL level. The TaqlB mutation could influence sLDL level by decreasing CETP activity in the presence of hypertriglyceridemia. The CETP TaqlB polymorphism did not influence TC, TG or LDL levels. (3) The CETP TaqlB polymorphism could induce the variance of HDL-C levels, but TaqlB polymorphism did not influence CHD risk either in men or in women.