Relationship between Homocysteine Level, White Matter Lesion and Cognitive Decline

Sohn, Jong Hee; Lee, Sun Yeob; Kim, Heung Cheol; Lee, Sang Moo; Choi, Hui Chul

Abstract

BACKGROUND: Hyperhomocysteinemia increase the risk of vascular disease, dementia and cognitive impairment. The effect of homocysteine on cognitive function may be as a consequence of direct neurotoxicity or indirectly through cerebrovascular disease. Thus we examined the association between homocysteine levels and cognitive function, and assess whether this may be mediated by cerebral white matter lesions.
METHODS
Non-dementic participants were recruited from March to December 2005, and underwent brain MRI. White matter hyperintensities(WMH) were rated visually by 4-class WMH grades. Informations of age, gender, education and vascular risk factor were obtained from interview. Cognitive function were assessed by using K-MMSE and HDS-R. The cross-sectional relationship between homocysteine level and cognitive test score was assessed by multiple regression analysis.
RESULTS
Severe WMH groups more exposed to vascular risk factor such as age, hypertension and higher levels of homocyteine. More severe WMH grades also had lower K-MMSE and HDS-R score. Higher group of homocysteine concentration were significantly related to poorer performances on K-MMSE and HDS-R tests. In multiple linear regression analyses for the relationship between homocysteine and cognitive performances, higher homocysteine level was also related to lower cognitive performances. Adding cerebral WMH changes to the level of homocysteine did not significantly change the effect of homocysteine on cognitive ability, and cerebral WMH had a separate and additive effect with homocysteine.
CONCLUSIONS
Elevated homocysteine level is associated decreased cognitive score and cerebral white matter lesion on MRI is independent association to the cognitive abilities.