[Factors determining hyperhomocysteinemia in the chronic phase of strokes].

Introduction: Several prospective and case-control studies have pointed to an association between hyperhomocysteinemia and ischaemic stroke.

Aim: To analyse the main factors determining hyperhomocysteinemia in the chronic phase of strokes.

Patients And Methods: We studied 280 patients with ischaemic stroke (130 subjects < 45 years old; 150 > 45 years old; 50.7% males) who were admitted to the Neurology Service consecutively over the years 2002 and 2003. Both plasma levels of homocysteine (Hc) and the mutation of the gene for 5, 10-methylenetetrahydrofolate reductase (MTHFR) were determined. An analysis was conducted to determine the distribution of the mean levels of Hc according to the aetiological subtype of stroke (TOAST classification) and the presence of vascular risk factors.

Results: Hc levels were found to be above normal (> 13 micromol/L) in 44.3% of cases. Hyperhomocysteinemia was more frequent in those above the age of 45 (55.3 versus 31.5%; p < 0.01). The mean Hc value was 16.3 micromol/L and was high both in young patients (15.1 +/- 14.9 micromol/L) and in adults (17.4 +/- 9.1 micromol/L). Results showed that 42.5% were carriers of the C677T mutation (7.1% in homozygosis and 35.4% in heterozygosis). There were more young patients carrying the homozygotic mutation than adults (9.2 versus 5.3%; p = 0.05). Hc levels in plasma were significantly higher (p < 0.01) in patients who were carriers of the homozygotic mutation (29.4 versus 14.2 micromol/L). The main factors determining hyperhomocysteinemia in the multiple linear regression analysis were: age, mutation of the gene for MTHFR, smoking and being male (R = 0.386).

Conclusion: Genetic and environmental factors determine the levels of Hc in the chronic phase of strokes.