ABSTRACT
OBJECTIVES: To assess whether 2 polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, are risk factors for vascular complications in Tunisian patients with type 2 diabetes mellitus. METHODS: The MTHFR polymorphisms were genotyped, and plasma homocysteine levels were evaluated in 160 Tunisian patients with type 2 diabetes mellitus. RESULTS: Prevalence of the 2 heterozygous polymorphisms of the thermolabile MTHFR gene (CT and AC) was encountered more commonly in patients with diabetes mellitus than in the healthy controls (p<10-3). Subjects with diabetes had significantly higher homocysteine (Hcy) levels than the control subjects; however, there was no statistical difference in plasma Hcy values between carriers of mutant genotypes (CT/TT for C677T and AC/CC for A1298C) and wild types (CC and AA) in patients with diabetes. Retinopathy was found to be a vascular complication in patients with either the 677CT or the 1298(AC+CC) genotype more commonly than in those with the wild-type genotypes (p=0.003; OR=3.2, 95% CI, 1.4 to 7.4; p<10-3; OR=5.9, 95% CI, 2.7 to 13). Only patients who carry the A1298C mutation (AC+CC) are at risk for at least 1 complication (p=0.002). Double heterozygous mutants were at the greatest risk for retinopathy and for suffering at least 1 complication (p<10-3). CONCLUSIONS: Studies involving a larger study population and various ethnic groups are required before ruling out the role of MTHFR gene in type 2 diabetes mellitus and in vascular complications.
Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/genetics , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Polymorphism, Single Nucleotide/genetics , Vascular Diseases/epidemiology , Vascular Diseases/genetics , Adult , Diabetic Retinopathy/epidemiology , Diabetic Retinopathy/genetics , Female , Humans , Hypertension/epidemiology , Hypertension/genetics , Male , Middle AgedABSTRACT
Previous studies have suggested that hyperhomocysteinaemia (Hcy) could be a strong and independent cardiovascular risk factor. Many factors could influence the serum concentration of Hcy such as vitamin B 12, folic acid, renal failure, hypothyroid status, ovarian failure and cancers. So the aim of our study was to evaluate the prevalence of hyperhomocysteinaemia among 54 type 2 diabetic patients and to study, its relationship with vitamin B12, folic acid and Metformin. Were excluded all patients with an evident cause of hyperhomocysteinaemia. Mean age of patients was 52.8 years. Mean Hcy was 11.7 + 6.9 micromol/l. The prevalence of hyperhomocysteinaemia was 27.8% in our group. There were eight (14%) patients with vitamin B12 deficiency and three among them had hyperhomocysteinaemia. There was no folic acid deficiency and no relationship with Metformin treatment. We suggest a wide screening of hyperhomocysteinaemia in type 2 diabetic patients and folic acid or vitamin B12 supplements if necessary.
