AIM:To examine the association between obesityrelated adipokines(adiponectin,leptin,resistin,interleukin-6(IL-6),and tumor necrosis factor-α(TNF-α)and colorectal cancer(CRC)risk.METHODS:Serum levels of adipokines were measured in 100 CRC patients and age-and sex-matched controls for the data analysis.Unconditional logistic regression models were used for estimating ORs and95%CIs related to each adipokine.For the metaanalysis,studies published before July 2013 available on Medline/PubMed and EMBASE were retrieved.The analysis included a total of 17 relevant studies(including the present case-control study):nine studies on adiponectin and eight on leptin.The effect sizes of ORs and 95%CIs were estimated using RevMan 5.1.Heterogeneity was evaluated using Cochran’s Q-test and I2 statistics.RESULTS:Among the five adipokines,only resistin levels were significantly higher in cases than in controls(P<0.001).The case-control study results showed no association between adiponectin and CRC and a negative association between leptin and CRC.However,the results of the meta-analysis showed a significant inverse association between adiponectin and CRC(OR=0.91,95%CI:0.83-1.00,P=0.04)and no association between CRC and leptin.After stratification by study design,an inverse association between adiponectin and CRC was observed in prospective studies only(OR=0.90,95%CI:0.82-0.99,P=0.03),whereas the association between leptin and CRC was inconsistent(prospective studies:OR=1.14,95%CI:1.02-1.27,P=0.02 and retrospective studies:OR=0.47,95%CI:0.29-0.74,P=0.001).The associations of resistin and TNF-αwith CRC risk were positive,but no association was observed for IL-6.CONCLUSION:Our results suggest a negative association of leptin,positive associations of resistin and TNF-α,and null associations of adiponectin and IL-6with CRC.However,further studies with larger number of prospective approaches are needed. AIM: To examine the association between obesityrelated adipokines (adiponectin, leptin, resistin, interleukin-6 (IL-6), and tumor necrosis factor-a were measured in 100 CRC patients and age-and sex-matched controls for the data analysis. Unconditional logistic regression models were used for estimating ORs and 95% CIs related to each adipokine. For the metaanalysis, studies published before July 2013 available on Medline / PubMed and EMBASE were retrieved. The analysis included a total of 17 relevant studies (including the present case-control study): nine studies on adiponectin and eight on leptin. The effect sizes of ORs and 95% CIs were estimated using RevMan 5.1. Heterogeneity was evaluated using Cochran’s Q-test and I2 statistics .RESULTS: Among the five adipokines, only resistin levels were significantly higher in cases than in controls (P <0.001). The case-control study results showed no association between adiponectin and CRC an da negative association between leptin and CRC. However, the results of the meta-analysis showed a significant inverse association between adiponectin and CRC (OR = 0.91, 95% CI: 0.83-1.00, P = 0.04) and no association between CRC and leptin . After stratification by study design, an inverse association between adiponectin and CRC was observed in prospective studies only (OR = 0.90, 95% CI: 0.82-0.99, P = 0.03), the association between leptin and CRC was inconsistent : OR = 1.14, 95% CI: 1.02-1.27, P = 0.02 and retrospective studies: OR = 0.47, 95% CI: 0.29-0.74, P = 0.001) .The associations of resistin and TNF- but no association was observed for IL-6.CONCLUSION: Our results suggest a negative association of leptin, positive associations of resistin and TNF-α, and null associations of adiponectin and IL-6 with CRC. Still, further studies with larger number of prospective approaches are needed.