POLYMORPHISMS OF THE APOLIPOPROTEIN-B AND APOLIPOPROTEIN-E GENES AND THEIR RELATIONSHIP TO PLASMA-LIPID VARIABLES IN HEALTHY CHINESE MEN

In this study we have analysed the apolipoprotein (Apo) E polymorphism and polymorphisms of the ApoB gene, including the ApoB/XbaI and ApoB/ 4311 diallelic polymorphisms and a hypervariable region (HVR) situated in the 3' region of the gene (ApoB/3'HVR), in a sample of healthy mal e subjects from Taiyuan (northern People's Republic of China). In comp arison to Caucasian populations, in the Chinese sample, the XbaI2 alle le (presence of cutting site; frequency 6.1%; and 95% confidence inter val, 3.3-8.9) and the long HVR alleles (9.4%; 6.0-12.8) were rare, whe reas the ApoB/4311 (Ser) allele (70.8%; 65.4-76.2) and the 34-repeat a llele of the HVR (HVR34; 62.4%; 56.8-68.0) were frequent. In subjects having none, one, or two HVR34 alleles, the mean levels of plasma trig lycerides were 2.32 +/- 1.44 (SD), 1.45 +/-0.74, and 1.75 +/- 1.07 g/l , respectively (P < 0.007). Similar trends were observed for very low density lipoprotein (VLDL) cholesterol, LpE:B, and LpCIII: B. The freq uencies of the ApoE alleles were similar to those reported in other po pulations of Asian origin; E2 (7.4%; 4.2-10.6), E3 (84.4%; 80.2-88.6), and E4 (8.2%; 5.0-11.4). Individuals carrying the E2 allele had a low er mean level of ApoB than E33 individuals: 0.87 +/- 0.16 and 1.00 +/- 0.22 g/l, respectively (P < 0.007). Individuals carrying the E4 allel e had higher levels of ApoE than E33 individuals: 0.140 +/- 0.084 and 0.094 +/- 0.052 g/l, respectively (P < 0.004); similar trends were obs erved for VLDL cholesterol, triglycerides, LpE:B, and LpCIII:B. The Ap oB/HVR34 and ApoE/E4 polymorphisms accounted for 10% to 15% of the var iability of the plasma levels of VLDL cholesterol, ApoE, triglycerides , LpE:B, and LpCIII:B. Several lipid variables appeared to be favourab ly affected by specific forms of ApoB and ApoE that are particularly f requent in this Chinese population.