Role of Vitamin D Receptor (BsmI-VDR) and Insulin Receptor (NsiI-A/G) Gene Polymorphisms in Colorectal Adenoma Susceptibility

Vitamin D deficiency and type 2 diabetes mellitus are risk factors for colorectal cancer, suggesting a role for vitamin D receptor (VDR) and insulin receptor (INSR) gene polymorphisms. We investigated the prevalence of the VDR-BsmI (rs1544410) and NsiI A/G-INSR (rs2059806) polymorphisms and their associations with colorectal adenoma (CRA) in a Romanian population. A case-control study was conducted with 110 participants (67 with CRA and 43 controls) who underwent colonoscopy. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to determine the genotype and allele frequencies of the two polymorphisms. Regarding rs1544410 and CRA patients, genotype distribution was 35% B/B, 47% B/b, and 19% b/b. In the controls, the distribution was 21% B/B, 45% B/b, and 34% b/b. For rs2059806, 12% of CRA patients had A/A, 30% A/G, and 58% G/G, while 8% of the controls had A/A, 40% A/G, and 52% G/G. The recessive model showed an odds ratio of 2.84 (95% CI: 1.04-7.72, = 0.033) for the b/b genotype. CRA patients with b/b or G/G genotypes were diagnosed at a younger age. The b allele of the rs1544410 was a risk factor for CRA. Patients with the b/b and G/G genotypes were diagnosed earlier.