Homocysteine, white matter hyperintensities, and cognition in healthy elderly people

Abstract

Hyperhomocysteinemia is associated with an increased risk of vascular disease, and recent results suggest that it also could increase the risk of dementia. We examined the relationship between homocysteine and cognitive decline in 1,241 subjects aged 61 to 73 years, followed up over 4 years. Plasma homocysteine levels were determined in all participants as well as cardiovascular risk factors, apolipoprotein E genotype, plasma levels of folate, and vitamin B12. Cognitive performances were assessed repeatedly by using Mini-Mental State Examination, Trail Making Test, Digit Symbol Substitution Test, and Finger Tapping Test. At 2-year follow-up, 841 subjects underwent cerebral magnetic resonance imaging, and white matter hyperintensities were rated visually. Analyses were adjusted for all cardiovascular risk factors. Cross-sectional analyses showed that higher concentrations of homocysteine were significantly related to poorer performances at all neuropsychological tests. Longitudinal analyses confirmed this finding. The odds of cognitive decline was 2.8-fold (p < 0.05) higher in subjects with homocysteine levels above 15 micromol/L compared with those with homocysteine levels below 10 micromol/L. In participants who underwent magnetic resonance imaging, the relationship between homocysteine and cognition was unchanged after taking into account white matter hyperintensities suggesting that white matter hyperintensities do not mediate the association between homocysteine and cognition.

Biochemical indicators of vitamin B 12 and folate insufficiency and cognitive decline

“…Serum methylmalonic acid (390 Ϯ 390 nmol/L) and homocysteine (16.5 Ϯ 6.2 mol/L) concentrations in the United Kingdom were also higher than those observed for our CHAP subjects. In a representative postfortification US sample of older adults, homocysteine levels ranged from 8 to 10.7 mol/L 31 ; in two prospective studies of older adults, 28,33 values were similar to those reported in the present study, which spans a pre-to perifortification period.…”

The heterogeneity of mild cognitive impairment: A neuropsychological analysis

“…Moreover, the fi gures reported above do not necessarily take into account the infl uence of risk factors for stroke and concomitant vascular disease. Given that newer research suggests that risk factors for stroke are also risk factors for AD (Dufouil, Alperovitch, Ducros, & Tzourio, 2003 ;Fernando & Ince, 2004 ;Riekse et al, 2004 ;Szolnoki et al, 2004 ), the fi gures reported above may be underestimating the prevalence of dementia.…”

Homocysteine and cognitive function in elderly people

“…Some have shown significant associations between homocysteine levels and cognitive function, 10,[12][13][14][15][16][17][19][20][21][22] whereas others have not. 11,18 An early study involving a small sample of a healthy elderly population in Italy showed no significant correlations between the Mini-Mental State Exam (MMSE) scores and homocysteine levels.…”