Relationship Between Plasma Homocysteine and Vitamin B12 Levels in Clinically Diagnosed Cases of Cardiovascular Accident in Lagos, Nigeria

Abstract

Vitamin B12 deficiency interferes with the normal pathway for homocysteine metabolism, even in the presence of adequate serum folate and pyridoxine. Homocysteinaemia, is an elevated level of homocysteine in plasma which has been established as a risk factor for the development of cardiovascular disorders. However, there has been conflicting report from various research works on the role of Vitamin B12 in the occurrence of major cardiovascular disorders. The study was set to determine the mean values of homocysteine, and correlate same with mean plasma levels of vitamin B12 in the subjects, and to estimate the prevalence of anaemia in the stroke patients, using Haemoglobin concentration (Hb) and mean corpuscular volume (MCV) as indices. One hundred (100) participants were recruited, comprising 40 clinically diagnosed stroke patients (hemorrhagic or thrombo-embolic), and 60 normal adults as control group. Plasma homocysteine levels were measured by HPLC and plasma vitamin B12 levels by Chemiluminescent Microparticle Immuno-assay method. Anticoagulated whole blood samples were evaluated for Hb, and MCV using automated Advia-60. Mean value of plasma homocysteine for the stroke patients (17.7±4.4umol/l) was significantly higher than values obtained in the control group at 9.5±2.4umol/l (p<0.001). Mean plasma vitamin B12 levels for both the stroke patients and controls were 249±14.5 pmol/l and 203.6±20.5 pmol/l respectively (p=0.029). The MCV for the study group (85fl) were significantly higher than those of the control group (82fl), p=0.040. However, the study showed no correlation between rising plasma homocysteine in stroke patient and vitamin B12 deficiency.