Hyperhomocysteinemia and elevated ox-LDL in Tunisian type 2 diabetic patients: role of genetic and dietary factors.

INTRODUCTION: Total plasma homocysteine (tHcy) is an emerging risk factor for the development of atherosclerosis. However, its relationship with diabetes is still unclear.

OBJECTIVES: We evaluated the association between tHcy levels and methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype in a type 2 diabetes mellitus (DM) population and their relationship with oxidized LDL (ox-LDL) according to dietary habits and vascular complications.

DESIGN AND METHODS: Eighty-six DM patients were compared to 120 healthy volunteers.

RESULTS: Associated higher tHcy levels and significantly higher ox-LDL levels (p<0.001) were found in DM patients compared to healthy subjects. Homozygosity for the T allele of MTHFR was more frequent in diabetics than in healthy subjects (12.8% vs. 7.2%) and it was associated with higher tHcy levels. Moreover, this elevated level was associated with significantly higher ox-LDL levels in DM patients with hypertension (p<0.05). Improving folate and vitamin C intakes could have beneficial effects on lowering the tHcy and ox-LDL levels.

CONCLUSIONS: The interplay of genetic and dietary factors modulates the effect of homocysteine on cardiovascular risk factors.