Subsequent breakdown analysis by age showed that CETP rs4783961, MLXIPL rs35493868, and PON2 rs12704796 were significantly associated with CHD among individuals younger than 55 years of age (CETP rs4783961: χ2=8.966, df=1, p=0.011 by genotype; MLXIPL rs35493868: χ2=4.87, df=1, p=0.027 by allele; χ2=4.88, df=1, p=0.027 by dominant model; PON2 rs12704796: χ2=6.511, df=2, p=0.039 by genotype; χ2=6.210, df=1, p=0.013 by allele; χ2=5.03, df=1, p=0.025 by dominant model).