Homocysteine, Folate and Cognition in a Large Community-Based Sample of Elderly People – The 3C Dijon Study

Abstract

Background: Hyperhomocysteinemia is associated with an increased risk of cognitive impairment in the elderly. Recent studies suggest that folate level may also influence the course of cognitive decline. Objective: We performed the cross-sectional analysis of the relationship between homocysteine and folate levels and cognitive performances in a population-based study including 3,914 subjects aged 65 years and older. Method: Subjects had an evaluation of their cognitive level using five neuropsychological tests. A Cognitive Summary Score was computed as the sum of each of the 5 cognitive tests score standardized. Relations of folate and homocysteine levels with cognition were first studied separately in a covariance analysis. Stratified analyses were also performed because of interaction between folate and homocysteine in relation to cognition. Results: Subjects in the higher quartile of homocysteine (high homocysteine group) and subjects in the lower quartile of folate (low folate group) had consistently lower cognitive performances in all tests. When stratified on folate level, high homocysteinemia was associated with lower cognitive performances only in subjects with a low folate level. Conclusion: In this large population-based sample of elderly people, the association between high homocysteinemia and decreased cognition was only seen in participants with low folate levels.

Effects of a multi‐vitamin/mineral supplement on cognitive function and fatigue during extended multi‐tasking

“…Again, this figure is directly in between the percentages quoted in the above surveys. Levels of folic acid, and vitamins B6 and B12 are closely related to the metabolism of homocysteine (Selhub, 2002) and both have been shown to be related to cognitive function/decline, with higher levels of B vitamins and lower levels of homocysteine predicting better performance (Durga et al, 2006;Duthie et al, 2002;Elias et al, 2006;Elias et al, 2008;Feng et al, 2006;Kado et al, 2005;Vidal et al, 2008). However, the causal relationship between these physiological factors and brain function is far from clear (Elias et al, 2006;Krieg and Butler, 2009).…”

“…A range of dietary minerals is also required for adequate CNS functioning, with iron particularly prevalent on the basis both of high levels of symptomatic deficiency, and the plethora of processes it contributes to. These include: myelination, synthesis of haem-containing enzymes, neurotransmitter synthesis and modulation of neurotransmitter activity (Gulyani et al, 2009). This integral relationship between vitamins and brain function is particularly relevant in light of data showing that a sizeable proportion of adults in developed countries are marginally deficient in one or more vitamins or minerals (Adams and Hewison, 2010;Ruston et al, 2004;Schleicher et al, 2009), with these deficiencies exacerbated in low socio-economic status groups (Nelson et al, 2007;Schleicher et al, 2009 (Bjelland et al, 2003;Kim et al, 2008;Sanchez-Villegas et al, 2009;Tiemeier et al, 2002), and cognitive function (Durga et al, 2006;Duthie et al, 2002;Elias et al, 2006Elias et al, , 2008Feng et al, 2006;Kado et al, 2005;Vidal et al, 2008). However, the inter-relationship between B vitamins and homocysteine levels, and the causality of the relationships, if any, with brain function has not yet been adequately elucidated (Elias et al, 2006;Krieg and Butler, 2009).…”

Advances in Vascular Cognitive Impairment

“…32 The Three-City study failed to identify any correlation between B12 and cognition but did find a correlation with low folate and with high homocysteine, although only when folate levels were low. 33 The Framingham Offspring Study found that homocysteine was correlated with atrophy and silent infarcts, even after correction for folate, cyanocobalamin, and pyridoxine levels, which were all lower in those with higher homocysteine levels. There was no correlation between homocysteine and leukoaraiosis; although continuous data were available for leukoaraiosis, the analysis was limited to a dichotomized method based on "extensive" leukoaraiosis.…”

“…Эти дополнительные данные представлены в таблице 2 [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”

“…Однако дополнительные данные исследования Rotterdam Scan Study, в котором проводили определение биологической активности B 12 и гомоцистеина, представили подобные взаимосвязи только при ограниченном влиянии уровня гомоцистеина [32]. В исследовании Three-City study не удалось выявить корреляционную связь между содержанием витамина B 12 и изменением когнитивных функций, но выявили корреляцию между низким содержанием фолатов и повышенным уровнем гомоцистеина [33]. В исследовании Framingham Offspring Study обнаружили, что содержание гомоцистеина коррелировало с наличием атрофии и "немых" инфарктов, даже после коррекции по содержанию фолатов, цианокобаламина и пиридоксина, которые были снижены у лиц с повышенным содержанием гомоцистеина.…”