Hyperhomocysteinaemia in black patients with cerebral thrombosis.

Hyperhomocysteinemia is regarded as a risk factor for stroke but its pathogenetic role has not yet been established in Black patients. We studied 24 Black patients admitted with cerebral thrombosis, and compared them with age- and sex-matched apparently healthy controls from the same community. Total homocysteine (tHcy) (free homocysteine, protein-bound homocysteine, the disulfide homocystine and the mixed disulfide homocysteine-cysteine) concentration was 10.91 (4.95-23.05) mumol/l in the stroke patients and 8.73 (3.95-15.10) mumol/l in controls (p = 0.031). This difference could not be explained by differences in vitamin B12, vitamin B6 or folate status. A subgroup of nine stroke patients with hypercreatininaemia (> 90 mumol/l, 75% of control concentrations) had significantly higher plasma tHcy concentrations [median (range) 9.10 (5.40-15.10) mumol/l] compared with controls [8.65 (3.96-13.89) mumol/l] (p = 0.002). Plasma tHcy concentrations of stroke patients with normal serum creatinine concentrations were not significantly different to those of controls. Hyperhomocysteinemia in Black patients with stroke may be partially caused by renal insufficiency. Therefore, while hyperhomocysteinemia may increase the risk of stroke, it is unlikely to be a primary initiating factor.