Meta-analysis of MTHFR C677T polymorphism and type 2 diabetes mellitus in MENA region

Background and aims: The association of the C677T polymorphism of the Methylenetetrahydrofolate Reductase (MTHFR) gene with susceptibility to type 2 diabetes mellitus (T2DM) has been widely debated. Therefore, our aim is to conclusively resolve this controversy in the Middle East and North Africa region population through a meta -analysis. Materiel and methods: We identified relevant articles by searching literature databases, such as PubMed, Web of Science, and Science Direct, to retrieve studies that examined the association between the MTHFR C677T polymorphism and the risk of developing T2DM. Using meta -analysis, we calculated the odds ratio (OR) and confidence interval (CI) values of these studies to assess the susceptibility to T2DM related to the C677T polymorphism of MTHFR gene. Results: In this meta -analysis, we included a total of 13 publications comprising 2072 T2DM patients and 2164 control subjects. The results of the meta -analysis suggested that there is a significant association between the C677T polymorphism and T2DM risk in overall comparisons for allele contrasts (T vs C): OR = 1.25, 95% CI = 1.04-1.50, p = 0.015 and homozygous (TT vs CC): OR = 1.44, 95% CI = 1.01-2.05, p = 0.038). Subgroup analysis revealed that the C677T polymorphism is associated with a risk of T2DM in Asian populations, while there is no significant association between this polymorphism and T2DM in Caucasian and African populations. Furthermore, there was no evidence of publication bias. Conclusion: Our study's results suggest that the allele contrast of the C677T polymorphism of the MTHFR gene is associated with an increased risk of T2DM in the overall population, particularly among Asians.