%0 Journal Article %J J Alzheimers Dis %D 2018 %T Homocysteine and Cerebral Atrophy: The Epidemiology of Dementia in Singapore Study. %A Tan, Bryce %A Venketasubramanian, Narayanaswamy %A Vrooman, Henri %A Cheng, Ching-Yu %A Wong, Tien Yin %A Ikram, Mohammad Kamran %A Chen, Christopher %A Hilal, Saima %K Aged %K Atrophy %K Biomarkers %K Dementia %K Female %K Homocysteine %K Humans %K Magnetic Resonance Imaging %K Male %K Middle Aged %K Organ Size %K Risk Factors %K Singapore %K White Matter %X

BACKGROUND: Plasma homocysteine levels are increasingly studied as a potential risk factor for dementia. Elevated homocysteine levels have been linked with gray and white matter volume reduction among individuals with mild cognitive impairment and Alzheimer's disease. However, the effects of homocysteine on brain changes in preclinical stages of dementia remain unexplored.

OBJECTIVE: To examine the association of elevated homocysteine levels with markers of neurodegeneration, i.e., white and gray matter volume in an elderly population.

METHODS: The study included 768 participants (mean age: 69.6±6.5 years, 51.3% women) from the Epidemiology of Dementia In Singapore study. Participants underwent a brain MRI scan and blood tests. Serum homocysteine was measured using competitive immunoassay. Cortical thickness and subcortical structural volume were quantified using FreeSurfer whereas white matter volume was quantified using a previous validated method.

RESULTS: Higher homocysteine levels were significantly associated with decreased global white matter volume [mean difference (β) in volume (ml) per micromole per liter (μmol/l) increase in homocysteine levels: - 0.555, 95% Confidence Interval (CI): - 0.873; - 0.237], decreased parietal cortical thickness [β in thickness (μm) per μmol/l increase in homocysteine levels:- 1.429, 95% CI: - 2.781; - 0.077], and smaller volumes of the thalamus [β: - 0.017, 95% CI: - 0.026; - 0.008], brainstem [β: - 0.037, 95% CI: - 0.058; - 0.016], and accumbens [β: - 0.004, 95% CI: - 0.006; - 0.002].

CONCLUSION: Higher homocysteine levels were associated with cerebral atrophy. Further studies are required to assess whether lowering plasma homocysteine levels may prevent neurodegenerative changes or delay progression of clinical symptoms before the development of dementia.

%B J Alzheimers Dis %V 62 %P 877-885 %8 2018 %G eng %N 2 %1 http://www.ncbi.nlm.nih.gov/pubmed/29480177?dopt=Abstract %R 10.3233/JAD-170796 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Apolipoprotein ɛ4 is Associated with Dementia and Cognitive Impairment Predominantly Due to Alzheimer's Disease and Not with Vascular Cognitive Impairment: A Singapore-Based Cohort. %A Chai, Yuek Ling %A Yeo, Hazel Kai-Hui %A Wang, Jiehao %A Hilal, Saima %A Ikram, Mohammad Kamran %A Venketasubramanian, Narayanaswamy %A Wong, Boon-Seng %A Chen, Christopher Li-Hsian %K Aged %K Aged, 80 and over %K Alzheimer Disease %K Analysis of Variance %K Apolipoprotein E4 %K Cognition Disorders %K Cohort Studies %K Dementia %K Female %K Genetic Association Studies %K Genotype %K Humans %K Male %K Middle Aged %K Neuroimaging %K Neuropsychological Tests %K Psychiatric Status Rating Scales %K Singapore %K Vascular Diseases %X

BACKGROUND AND OBJECTIVE: While the association for apolipoprotein ɛ4 allele (APOE4) with Alzheimer's disease (AD) has been consistently confirmed, the association with vascular cognitive impairment (VCI) is unclear. We therefore explored the relationship of APOE with both AD and cerebrovascular disease (CeVD) by examining the prevalence of APOE4 in AD, AD with CeVD and vascular dementia (VaD), as well as in cognitive impairment no dementia (CIND) with and without CeVD.

METHODS: We performed a case-control study with subjects recruited from memory clinics and the community. All subjects underwent standardized brain neuroimaging, clinical and neuropsychological assessments, following which they were classified using research criteria.

RESULTS: A total of 411 subjects; 92 controls with no cognitive impairment (NCI), 77 CIND without CeVD, 87 CIND with CeVD, 55 AD without CeVD, 68 AD with CeVD, and 32 VaD patients were recruited. Compared to NCI (16.3%), the prevalence of APOE4 carriers was significantly higher only in CIND (37.7%) and AD in the absence of CeVD (45.5%), but not in the three subgroups of VCI, namely CIND with CeVD (20.7%), AD with CeVD (27.9%) and VaD (25.0%). Logistic regression analyses also showed that APOE4 carriers were more likely to have CIND without CeVD (Odds Ratio [OR]: 3.34; 95% Confidence Interval [CI]: 1.59-7.03) and AD without CeVD (OR: 7.21; 95% CI: 2.74-18.98), but no such association was observed in the VCI subgroups.

CONCLUSION: APOE4 is significantly associated with dementia and CIND due to AD pathology, but not with VCI.

%B J Alzheimers Dis %V 51 %P 1111-8 %8 2016 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/26923016?dopt=Abstract %R 10.3233/JAD-150902