Association of <i>MTHFR</i> A1298C polymorphism and blood homocysteine levels with proteinuria in patients with type 2 diabetes mellitus

BackgroundA1298C polymorphism of the MTHFR gene and blood homocysteine levels are reported to be associated with the development of proteinuria in patients with type 2 diabetes mellitus; however, data remain limited.ObjectivesTo determine the characteristics of A1298C polymorphism and blood homocysteine levels as well as their association with proteinuria in patients with type 2 diabetes mellitus.Materials and methodsA cross-sectional study with convenient sampling was performed among patients with type 2 diabetes mellitus who visited the Can Tho University of Medicine and Pharmacy Hospital between August 2023 and August 2024. Blood samples were collected for genetic sequencing and homocysteine level testing. Proteinuria was defined as an albumin-to-creatinine ratio ≥30 mg/g.ResultsIn total, 192 patients with a mean age of 63.9 ± 13.1 years were enrolled. Males accounted for 34.9% of the study population. Analysis of A1298C polymorphism revealed genotype distributions of AA, AC, and CC genotypes as 51.6%, 41.1%, and 7.3%, respectively. A significant association was observed between A1298C polymorphism and elevated homocysteine levels, with CC genotype exhibiting a higher prevalence of hyperhomocysteinemia (28.6%) than AA (6.1%) and AC (22.8%) genotypes. Patients carrying AC+CC genotypes had a 2.40-fold higher risk of developing proteinuria (95% confidence interval: 1.30-4.41, p <<i> </i>0.05) than those with AA genotype. Elevated blood homocysteine levels were associated with an 8.98-fold increased risk of proteinuria (95% confidence interval: 2.06-39.11, p <<i> </i>0.05). Independent factors associated with proteinuria included age (odds ratio = 0.97), elevated homocysteine levels (odds ratio = 8.79), and AC+CC genotype (odds ratio = 2.08).ConclusionA1298C polymorphism was characterized by allele frequencies of 72.1% for A and 27.9% for C. In addition to age, the presence of the C allele and elevated blood homocysteine levels were identified as independent risk factors for proteinuria in patients with type 2 diabetes mellitus.