Abstract
BACKGROUND: Colorectal cancer (CRC) is the fourth leading cause of cancer-related death around the world and accumulated evidence indicates the association between CRC and obesity and insulin resistance. OBJECTIVES: Regarding the role of adiponectin in obesity and insulin resistance, we explored whether genetic variants in adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) are associated with CRC risk. MATERIALS AND METHODS: ADIPOQ (rs2241766) and ADIPOR1 (rs2275738) gene variants were genotyped in 261 cases with CRC and 339 controls using PCR-RFLP method. RESULTS: In this study, no significant difference was observed for ADIPOQ gene rs2241766 variant between the cases and controls. However, carriers of the ADIPOR1 (rs2275738) "CC + CT" genotype compared with "TT" genotype occurred more frequently in the cases with CRC than the controls, and the difference remained significant after adjustment for age, BMI, sex, smoking status, NSAID use, and family history of CRC (P = 0.048; OR = 1.49, 95%CI = 1.01-2.20). Interestingly, after adjustment for confounding factors the ADIPOR1 "CC + TC" genotype compared with "TT" genotype was also associated with an increased risk for obesity in the cases (P = 0.040; OR = 1.86, 95%CI = 1.03-3.36). CONCLUSIONS: Our findings suggest for the first time that the - 106 C > T (rs2275738) variant of ADIPOR1 gene may be a genetic contributor to CRC and obesity risk in the cases with CRC. However, further studies with bigger sample size are needed to validate these findings.