Homocysteine and cerebral white matter lesions: the Rotterdam Scan Study
Background White matter lesions are frequently observed on cerebral MRI scans. There is evidence that white matter lesions are involved in the pathophysiology of cognitive decline, dementia and late-onset depression. Cardiovascular risk factors are associated with these lesions. A high homocysteine level is associated with an increased risk of cardiovascular disease. Therefore, we studied the association between homocysteine and white matter lesions. Method This study forms part of the Rotterdam Scan Study, a prospective population-based cohort study among 1077 subjects, aged 60 to 90 years. All participants underwent MRI scanning of the brain. White matter lesions were defined as hyperintense lesions on both proton-density and T2-weighted images, without prominent hypointensity on T1-weighted images. Periventricular white matter lesions were rated on a nine-point scale. For subcortical white matter lesions an approximated total lesion volume was calculated. Homocysteine levels were determined in plasma samples, obtained within 3 weeks before scanning. The association between total plasma homocysteine and white matter lesions was assessed through multiple linear regression analysis, adjusted for age and gender. Results The total plasma homocysteine levels ranged from 3.4 to 70.7 μmol/l with a mean of 11.7 μmol/l [95%CI 11.4–12.0]. We found a mean value of 2.4 [95%CI 2.3–2.5] for periventricular white matter lesion severity and of 1.4 ml [95%CI 1.2–1.6] for subcortical white matter lesion volume. Periventricular white matter lesions increased with 0.4 [95%CI 0.1–0.6] and subcortical white matter lesions with 0.5 ml [95%CI 0.1–0.8] per 10 μmol/l increase in homocysteine level. Conclusion Higher homocysteine levels are associated with an increased severity of both periventricular and subcortical white matter lesions.