Association of APOE genotype with lipid profiles and type 2 diabetes mellitus in a Korean population

Background Type 2 diabetes mellitus (T2DM) is associated with chronic hyperglycemia and lipid metabolism. A previous genome-wide association study revealed the TOMM40 - APOE region as novel locus for T2DM susceptibility. Objective This association study was conducted to determine the genetic effects of APOE single nucleotide polymorphisms (SNPs) on T2DM susceptibility and lipid profiles in a Korean population. Methods A total of 6 tagging SNPs, including rs7412 and rs429358 , were selected for ε genotype analysis and genotyped in 1436 subjects, consisting of 352 T2DM patients and 1084 unaffected controls. Results Logistic regression analyses were conducted and there were no significant associations among the APOE 6 tagging SNPs, ε genotypes, and haplotypes with T2DM susceptibility. To investigate the association of the APOE tagging SNPs with the lipid profiles, a regression analysis was conducted. As a result, rs7412 was significantly associated with the total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) levels ( P corr = 2.30 × 10 –5 and 3.39 × 10 –13 , respectively) in the unaffected controls. The ε2 allele and ε3 allele were significantly associated with the TC ( P corr = 4.46 × 10 –6 and 0.02, respectively) and LDL levels ( P corr = 3.54 × 10 –14 and 0.0006, respectively) in the unaffected controls. Further analysis of only the unaffected controls was conducted. As a result, the APOE alleles ε2 and ε3 showed a significant association with the TC and LDL levels ( P < 0.05). Conclusion The results of this study may help in understanding APOE polymorphisms and ε alleles and lipid profiles, which have been highly linked to T2DM, in a Korean population.