Association study between single nucleotide polymorphisms on retinol binding protein 4,FOXO1 and type 2 diabetes mellitus

Abstract

Objective To investigate the distribution of single nucleotide polymorphisms(SNPs) on retinol binding protein 4(RBP4) genes and forkhead box O1 (FOXO1) gene, and their relationships with the occurrence of type Ⅱ diabetes mellitus (T2DM) in Chinese Han population. Methods Totally ten SNPs on RBP4 and FOXO1 were determined in 384 T2DM patients and 384 normal controls by TaqMan probe genotyping and agarose gel electrophoresis methods. And their serum level of fasting blood glucose (FBG), total cholesterol (TC) and trigly- ceride (TG) were also estimated. Results For RBP4, there was no significance for various genetypes and alleles including - 803 G > A, + 5169 C > T, and + 6969 G > C between two groups (P > 0.05). Each genotype had no relationships with T2DM (using adjusted logistic regression models). No haplotype was associated with T2DM. For FOXO1, among seven SNPs typed, significant variation was found in the frequency distribution of rs7324943 G/T in the two groups(χ2=4.02, P = 0.044), and further stratification analysis showed that in subjects of aged 40 and non-hypertension, there was a higher risk of T2DM in GT heterozygous carriers than in GG homozygous carriers (OR = 1.47, 1.80), T allele carriers showed higher risk than non-T carriers (OR = 1.42,1.79). For rs17592236 C/T, though no significant frequency variation was found between two groups (χ2 = 0.39, P = 0.401), but in subjects of aged ≤ 40, stratification analysis showed dramatically increased risk of T2DM in CT and TT carriers than in CC carriers (OR = 6.33,10.15), T allele carriers showed 7. 11-fold higher risk than non-T carriers. A haplotype CT related to T2DM susceptibility was also found, which could decrease the risk of its carriers by 28%. Conclusions For BBP4, the polymorphisms of - 803 G > A, + 5169 C > T, and + 6969 G > C had no relationships with T2DM in Chinese Han population. For FOXO1, the polymorphism of rs7324943 G/T,rs17592236 C/T and a haplotype CT were found related to the susceptibility of T2DM in Chinese Han population. Yet further studies are necessary to explain the impact of these polymorphisms on the disease occurrence. Key words: Diabetes mellitus; type 2; Retinolbinding proteins; plasma; Forkhead transcription factors; Polymorphism; single nucleotide