Methylenetetrahydrofolate reductase genetic polymorphism and the risk of diabetic nephropathy in type 2 diabetic patients

Background: As indicated by numerous studies, there exists a relationship between the polymorphism ofmethylenetetrahydrofolate reductase (MTHFR)and susceptibility to diabetic nephropathy (DN) in various populations; nonetheless, the findings remain inconsistent. Therefore, we carried out a meta-analysis to determine the relationship between theMTHFRgene polymorphism and DN susceptibility. Materials and method: Related studies were identified from PubMed, Cochrane Library, EMBASE, and the China National Knowledge Infrastructure database (time period: from building the library to October 2019). The strength of the association was examined using odds ratios (ORs) with 95% confidence intervals (95% CIs). Results: The findings illustrated that theC677Tgene polymorphism was significantly associated with an enhanced susceptibility to DN compared to that with diabetes mellitus in allelic (OR = 1.64,95% CI = 1.34-2.00,P < .001), dominant (OR = 1.85,95% CI = 1.40-2.46,P < .001), codominant (heterozygote:OR = 1.67,95% CI = 1.27-2.21,P OR = 2.55,95% CI = 1.82-3.57,P < .001), and recessive (OR = 1.89,95% CI = 1.50-2.38,P < .001) models of the overall population. Moreover, as compared with the healthy controls, a significantly augmented susceptibility to DN was found in all 5 genetic comparison models (allelic:OR = 2.06,95% CI = 1.58-2.67,P OR = 2.52,95% CI = 1.73-3.69,P OR = 3.78,95% CI = 2.50-5.70,P OR = 2.41,95% CI = 1.96-2.97,P < .001). Furthermore, stratifying data by ethnicity revealed substantially augmented vulnerability to DN in not only Caucasian but also Asian populations. Conclusion: The present study suggests that the C677T polymorphism was associated with an augmented susceptibility to DN.