Aim: To determine the differences in plasma homocysteine levels between three MTHFR 677 genotype subgroups in patients with thrombosis and in controls, as well as between patients with thrombosis and controls with the same MTHFR 677 genotype.
Methods: This case-control study was conducted in Clinical Center of Vojvodina, Novi Sad, from June to December 2011. We included 65 patients with either arterial or venous thrombosis (mean age, 40.97 ± 11.38 years) and 65 controls with no history or clinical evidence of any thrombotic event (mean age, 41.23 ± 11.12 years). Patients and controls were age- and sex-matched.
Results: In comparison with controls, thrombotic patients had significantly higher homocysteine levels (12.81 ± 4.94 µmol/L vs 9.82 ± 3.68 µmol/L; P<0.001) and significantly higher incidence of hyperhomocysteinemia (55% vs 22%; P<0.001; odds ratio [OR]=4.521). There were no significant differences in homocysteine levels between homozygous carriers, heterozygous carriers, and non-carriers of the MTHFR 677 mutation in either thrombotic patients (12.97 ± 5.40 µmol/L vs 12.55 ± 5.71 µmol/L vs 13.27 ± 1.71 µmol/L; P=0.100) or controls (10.07±2.50 µmol/L vs 10.25 ± 4.84 µmol/L vs 9.20 ± 2.44 µmol/L; P=0.651). However, in comparison with controls, homozygous carriers in thrombotic patient group did not have significantly higher levels of homocysteine (12.97 ± 5.40 µmol/L vs 10.07 ± 2.50 µmol/L; P=0.072), but heterozygous carriers (12.55 ± 5.71 µmol/L vs 10.25 ± 4.84 µmol/L; P=0.020) and non-carriers (13.27 ± 1.71 µmol/L vs 9.20 ± 2.44 µmol/L; P<0.001) did. There was no significant difference in homocysteine levels between patients with arterial and venous thrombosis (12.76 ± 3.60 µmol/L vs 12.86 ± 5.51 µmol/L; P=0.990) and between patients with one thrombotic event and those with recurrent thrombotic events (12.14 ± 3.20 µmol/L vs 15.25 ± 8.51 µmol/L; P=0.254).
Conclusion: Plasma homocysteine levels have a greater clinical significance in the prevention of thrombosis and managing its complications than MTHFR 677 genotyping.