Levels of Plasma Homocysteine in Persons with Spinal Cord Injury

Abstract

Background: Premature coronary vascular disease is a leading cause of morbidity and mortality in persons with chronic spinal cordinjury (SCI). Evidence indicates that an elevated plasma homocysteine level is an independent risk factor for vascular disease.Methods: Plasma homocysteine levels were collected in 845 subjects with SCI and compared to those in a reference population. Differences in plasma homocysteine were determined for sex, race/ ethnicity, neurological deficit, and age, as well as for serum creatinine concentration.Results: Plasma homocysteine was significantly higher in men than in women. Men were more likely to have moderately or severely elevated plasma homocysteine levels. Stratifying by male sex, greater percentages of whites and African Americans had severely elevated plasma homocysteine levels (>20 11moi/L) compared with Latinos (12% and 14% versus 8%; P > .01 J. For the total group with SCI, plasma homocysteine levels were not significantly different by race/ ethnicity or neurological deficit subgroup. For the total group (P < .05) and within each sex (men, P < .05; women, P < .01 ), the older age group with SCI (>50 years) had significantly higher mean plasma homocysteine levels than the younger age group. Age was positively related to plasma homocysteine levels in men (P < .05) and women (P <.01 J. Plasma homocysteine levels were higher among men for any given age than among women (P <.0001) by an average of 3.19 ± 0.51 µmoi/L. Regardless of age or sex, persons with SCI tended to have higher levels of plasma homocysteine than able-bodied persons matched for age and sex.Conclusion: Because the risk of a vascular event increases with age, elevated levels of plasma homocysteine place older persons with SCI at further increased risk for a vasa-occlusive event. Of note, there was a stepwise increase in plasma homocysteine concentration for each quartile of higher serum creatinine concentration. Patients who have elevated levels of plasma homocysteine should receive a trial course of daily supplementation with oral folic acid and vitamin B12 . If that is ineffective, they should receive vitamin B6 supplementation to lower their plasma homocysteine levels.