Amyloid-Independent Amnestic Mild Cognitive Impairment and Serum Apolipoprotein A1 Levels.

OBJECTIVES: The present study investigated the characteristics of amnestic mild cognitive impairment (aMCI) in subjects with low brain amyloid-beta (Aß) burden. Furthermore, the relationships between amyloid-independent cognitive decline and serum lipid profiles, particularly apolipoprotein A1 (APOA1), were evaluated. DESIGN: Cross-sectional and longitudinal follow-up study. SETTING: University hospital dementia clinic. PARTICIPANTS: 28 aMCI and 35 cognitive normal (CN) elderly. MEASUREMENTS: The study measures included baseline assessments of the subjects' clinical characteristics, lipid profiles, and magnetic resonance imaging and (11)C-labelled Pittsburgh Compound B (PiB) positron emission tomography scans. Based on PiB retention at baseline, the aMCI subjects were divided into low Aß (aMCI-) and high Aß (aMCI+) subgroups. All aMCI subjects were followed up over a 1-year period. RESULTS: The aMCI- group had a longer duration of illness than did the aMCI+ group. None of the aMCI- subjects were diagnosed with Alzheimer disease (AD) dementia during the 1-year follow-up period, whereas 26.7% of aMCI+ subjects developed AD dementia. The aMCI- group also exhibited lower serum APOA1 levels compared with both the aMCI+ and CN groups. Additionally, lower serum APOA1 levels were associated with cognitive decline and brain atrophy independent of Aß deposition and vascular burden. CONCLUSIONS: Patients with aMCI- likely exhibit different clinical and pathophysiological characteristics than patients with aMCI+. Additionally, APOA1 may be an important contributor underlying amyloid-independent neurodegeneration.

Association Between Serum Triglycerides and Cerebral Amyloidosis in Cognitively Normal Elderly.

OBJECTIVES: Although many preclinical studies have suggested the possible linkage between dyslipidemia and cerebral amyloid deposition, the association between serum lipid measures and cerebral amyloid-beta (Aß) deposition in human brain is still poorly known. We aimed to investigate the association in cognitively normal (CN) elderly individuals. DESIGN: Cross-sectional study. SETTING: University hospital dementia clinic. PARTICIPANTS: 59 CN elderly. MEASUREMENTS: The study measures included comprehensive clinical and neuropsychological assessment based on the CERAD protocol, magnetic resonance imaging and (11)C-labelled Pittsburgh Compound B positron emission tomography scans, and quantification for serum lipid biomarkers. RESULTS: Multiple linear regression analyses showed that a higher serum triglycerides level was associated with heavier global cerebral Aß deposition even after controlling age, sex, and apolipoprotein E ε4 genotype. Serum apolipoprotein B also showed significant positive association with global cerebral Aß deposition, but the significance disappeared after controlling serum triglycerides level. No association was found between other lipid measures and global cerebral Aß deposition. CONCLUSIONS: The findings suggest that serum triglycerides are closely associated with cerebral amyloidosis, although population-based prospective studies are needed to provide further evidence of the causative effect of triglycerides on cerebral amyloidosis.

Frequency of Depressive Syndromes in Elderly Individuals with No Cognitive Impairment, Mild Cognitive Impairment, and Alzheimer's Disease Dementia in a Memory Clinic Setting.

AIMS: The aims of this study were to investigate the frequency of various depressive syndromes in elderly individuals with no cognitive impairment (NC), mild cognitive impairment (MCI), and Alzheimer's disease dementia (AD) in a memory clinic setting, and then to test whether severe and milder forms of depressive syndromes are differentially associated with the cognitive groups. METHODS: For 216 NC, 478 MCI, and 316 AD subjects, we investigated the frequency of depressive syndromes, defined by three different categories: major and minor depressive disorder (MaDD and MiDD) according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, as well as depression according to the National Institute of Mental Health provisional diagnostic criteria for depression in Alzheimer's disease (NIMH-dAD). RESULTS: The frequency of MaDD did not show any significant difference among NC, MCI, and AD. In contrast, the frequencies of MiDD and NIMH-dAD were higher than those of MaDD and showed significant group differences with a gradual increase from NC to AD. CONCLUSION: The findings suggest that the degenerative process of Alzheimer's disease contributes to the occurrence of mild depressive conditions, but not to severe depression.

Multicenter, randomized, placebo-controlled, double-blind clinical trial of escitalopram on the progression-delaying effects in Alzheimer's disease.

OBJECTIVES: A series of preclinical studies have suggested that selective serotonin reuptake inhibitor antidepressants not only stimulate neurogenesis but also have neuroprotective effects. The present study primarily aimed to investigate whether escitalopram would decelerate the brain atrophy of patients with mild-to-moderate Alzheimer's disease (AD). We also assessed the effects of escitalopram on the cognitive function and neuropsychiatric symptoms of these participants. METHODS: Seventy-four probable AD patients without major depression were recruited from four dementia clinics of university hospitals and randomly assigned in a 1:1 ratio. Each group received 20 mg/day of escitalopram or placebo for 52 weeks. The primary outcome measures were the change rates of hippocampal and whole brain volume on magnetic resonance imaging for 52 weeks. The Alzheimer's Disease Assessment Scale-cognitive subscale, Mini-Mental State Examination, Neuropsychiatric Inventory, and Cornell Scale for Depression in Dementia (CSDD) were also applied. RESULTS: We did not find any significant differences in the changes of hippocampal or whole brain volume between the groups. Escitalopram showed significant beneficial effects on the CSDD score at 28 weeks compared with placebo (t = -2.17, df = 50.42, p = 0.035), but this finding did not persist throughout the study. CONCLUSION: The findings of the present study do not support the role of escitalopram as a progression-delaying treatment for AD. However, the negative results of the present trial should be interpreted cautiously because of the relatively small sample size. Further large-scale escitalopram trials targeting the earlier stages of AD, even prodromal AD, are still needed. Copyright © 2015 John Wiley & Sons, Ltd.

Functional Neuroanatomical Correlates of The Frontal Assessment Battery Performance in Alzheimer Disease: A FDG-PET Study.

BACKGROUND/OBJECTIVES: We aimed to elucidate the functional neuroanatomical correlates of Frontal Assessment Battery (FAB) performances by applying [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) to a large population of patients with Alzheimer disease (AD). METHODS: The FAB was administered to 177 patients with AD, and regional cerebral glucose metabolism (rCMglc) was measured by FDG-PET scan. Correlations between FAB scores and rCMglc were explored using both region-of-interest-based (ROI-based) and voxel-based approaches. RESULTS: The ROI-based analysis showed that FAB scores correlated with the rCMglc of the dorsolateral prefrontal cortices. Voxel-based approach revealed significant positive correlations between FAB scores and rCMglc which were in various cortical regions including the temporal and parietal cortices as well as frontal regions, independent of age, gender, and education. After controlling the effect of global disease severity with Mini-Mental State Examination score, significant positive correlation was found only in the bilateral prefrontal regions. CONCLUSIONS: Although FAB scores are influenced by temporoparietal dysfunction due to the overall progression of AD, it likely reflects prefrontal dysfunction specifically regardless of global cognitive state or disease severity in patients with AD.

Comparison of regional gray matter atrophy, white matter alteration, and glucose metabolism as a predictor of the conversion to Alzheimer's disease in mild cognitive impairment.

We compared the predictive ability of the various neuroimaging tools and determined the most cost-effective, non-invasive Alzheimer's disease (AD) prediction model in mild cognitive impairment (MCI) individuals. Thirty-two MCI subjects were evaluated at baseline with [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET), MRI, diffusion tensor imaging (DTI), and neuropsychological tests, and then followed up for 2 yr. After a follow up period, 12 MCI subjects converted to AD (MCIc) and 20 did not (MCInc). Of the voxel-based statistical comparisons of baseline neuroimaging data, the MCIc showed reduced cerebral glucose metabolism (CMgl) in the temporo-parietal, posterior cingulate, precuneus, and frontal regions, and gray matter (GM) density in multiple cortical areas including the frontal, temporal and parietal regions compared to the MCInc, whereas regional fractional anisotropy derived from DTI were not significantly different between the two groups. The MCIc also had lower Mini-Mental State Examination (MMSE) score than the MCInc. Through a series of model selection steps, the MMSE combined with CMgl model was selected as a final model (classification accuracy 93.8%). In conclusion, the combination of MMSE with regional CMgl measurement based on FDG-PET is probably the most efficient, non-invasive method to predict AD in MCI individuals after a two-year follow-up period.

A normative study of total scores of the CERAD neuropsychological assessment battery in an educationally diverse elderly population.

BACKGROUND: This study aimed to investigate the influences of age, education, and gender on the two total scores (TS-I and TS-II) of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological assessment battery (CERAD-NP) and to provide normative information based on an analysis for a large number of elderly persons with a wide range of educational levels. METHODS: In the study, 1,987 community-dwelling healthy volunteers (620 males and 1,367 females; 50-90 years of age; and zero to 25 years of education) were included. People with serious neurological, medical, and psychiatric disorders (including dementia) were excluded. All participants underwent the CERAD-NP assessment. TS-I was generated by summing raw scores from the CERAD-NP subtests, excluding Mini-Mental State Examination and Constructional Praxis (CP) recall subtests. TS-II was calculated by adding CP recall score to TS-I. RESULTS: Both TS-I and TS-II were significantly influenced by demographic variables. Education accounted for the greatest proportion of score variance. Interaction effect between age and gender was found. Based on the results obtained, normative data of the CERAD-NP total scores were stratified by age (six overlapping tables), education (four strata), and gender. CONCLUSIONS: The normative information will be very useful for better interpretation of the CERAD-NP total scores in various clinical and research settings and for comparing individuals' performance of the battery across countries.

Protein intake and episodic memory: the moderating role of the apolipoprotein E ε4 status.

BACKGROUND: This study investigated the correlation between protein intake and Alzheimer's disease (AD)-related cognitive decline, particularly in episodic memory, among older adults without dementia. Furthermore, we assessed the moderating effect of apolipoprotein ε4 (APOE4) on this association and analyzed its influence on other cognitive functions beyond memory. METHODS: The study involved 196 participants who underwent assessments for protein intake, cognitive performance, APOE4 genotyping, and nutritional biomarkers. Protein intake was categorized into low, medium, and high based on the consumption of dairy, legumes, eggs, meat, and fish. RESULTS: High protein intake was significantly associated with better episodic memory and overall cognition. Moreover, a significant interaction was found between high protein intake and APOE4, indicating that APOE4 moderates the association between high protein intake level and episodic memory. Sensitivity analysis confirmed these results among participants with stable food intake. CONCLUSIONS: Our study results demonstrated that high protein intake is associated with better episodic memory among older adults without dementia. Furthermore, the findings highlight the significant role of APOE4 status in moderating the relationship between protein consumption and episodic memory. These results suggest that dietary interventions focusing on protein intake could be beneficial for cognitive health, particularly in individuals with a genetic predisposition to AD.

Implications of helplessness in depression: diagnosing mild cognitive impairment and analyzing its effects on cognitive decline in older adults.

Background: This study focuses on how elements of depression correlate with mild cognitive impairment (MCI) in older adults and the diagnostic efficacy of combining these components with the Mini-Mental State Examination (MMSE). The study also investigated the connection between individual depression components and overall cognitive function, as measured by the total score (TS) of the consortium to establish a registry for Alzheimer's disease (AD) assessment battery. Methods: The study included 196 nondemented adults aged 65 to 90 years at a university hospital and community. Comprehensive clinical assessments including the 30-item Geriatric Depression Scale (GDS) to measure components of depressive symptoms, TS, and blood nutritional biomarkers. Results: Our stepwise logistic regression analysis highlighted the 'helplessness item' (odds ratio = 4.531, 95% CI = 2.218 to 9.258, p < 0.001) as a significant predictor for MCI diagnosis. Further, models incorporating 'helplessness item + MMSE' demonstrated markedly enhanced accuracy in diagnosing MCI, surpassing the performance of the MMSE used independently. Notably, the group characterized by helplessness showed a significant reduction in TS (B = -5.300, SE = 1.899, ß = -0.162, p = 0.006), with this trend being particularly pronounced in individuals exhibiting lower levels of physical activity. Interestingly, this correlation did not manifest in participants with higher physical activity levels. Conclusion: Our findings suggest that helplessness is highly effective in diagnosing MCI and is linked to a decrease in cognitive function. Therefore, when addressing MCI and AD-related cognitive decline, clinicians should consider helplessness.

Influence of Sensory Impairments on Incidence of Dementia in the Korean Population.

OBJECTIVE: Previous studies have shown the influence of visual and auditory sensory impairment on dementia incidence. In this study, we tested the hypothesis that the incidence of dementia will increase with visual and auditory impairments than with visual or auditory impairment. METHODS: Data from the Korea National Health Insurance Service database were used, including disease and medication codes from 2009 to 2018, and the 2011 national health check-up results. Participants were grouped based on their sensory abilities: normal, visual impairment, auditory impairment, and both visual and auditory impairments (dual sensory impairment). To compare the incidence of dementia, hazard ratios were calculated for each group, with reference to the normal sensory (NS) group. Sensitivity analyses were performed comparing dementia incidence from 2014 to 2018, excluding the onset of the disease in 2012 and 2013. RESULTS: We identified 8,289 cases of dementia during the seven-year follow-up. In the multiple Cox regression analysis, adjusted for sex, social economic status, age, comorbidities, smoking, alcohol consumption, and activity level, the auditory impairment (hazard ratio= 1.1908) and visual impairment (hazard ratio=1.3553) groups showed a significantly higher dementia incidence than the NS group. Dual sensory impairment (hazard ratio=1.5267) showed the highest incidence. The sensitivity analysis yielded similar results. CONCLUSION: Visual and auditory impairments are associated with an increased risk of dementia, particularly in individuals with dual sensory impairment. Hence, visual and auditory impairments might have increased the risk of dementia through independent pathological processes. Therefore, preventing and correcting sensory impairment is necessary to reduce the risk of dementia.

Association between physical activity and episodic memory and the moderating effects of the apolipoprotein E ε4 allele and age.

Background: An abundance of evidence indicates that physical activity may protect against Alzheimer's disease (AD) and related cognitive decline. However, little is known about the association between physical activity and AD-related cognitive decline according to age and the apolipoprotein E (APOE) ε4 allele (APOE4) as major risk factors. Therefore, we examined whether age and APOE4 status modulate the effects of physical activity on episodic memory as AD-related cognition in non-demented older adults. Methods: We enrolled 196 adults aged between 65 and 90 years, with no dementia. All participants underwent comprehensive clinical assessments including physical activity evaluation and APOE genotyping. The AD-related cognitive domain was assessed by the episodic memory, as the earliest cognitive change in AD, and non-memory cognition for comparative purposes. Overall cognition was assessed by the total score (TS) of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery. Results: We found significant physical activity × age and physical activity × APOE4 interaction effects on episodic memory. Subgroup analyses indicated that an association between physical activity and increased episodic memory was apparent only in subjects aged > 70 years, and in APOE4-positive subjects. Conclusion: Our findings suggest that physical activity has beneficial effects on episodic memory, as an AD-related cognitive domain, in individuals aged > 70 years and in APOE4-positive individuals. Physicians should take age and APOE4 status account into when recommending physical activity to prevent AD-related cognitive decline.

Manganese level and cognitive decline in older adults with the APOE e4 allele: a preliminary study.

This study examined the relationship between serum manganese level and cognition, and the moderating effect of apolipoprotein E ε4 (APOE4) on this relationship. A total of 164 non-demented participants underwent clinical assessments including serum manganese level and cognition [episodic memory score (EMS), non-memory score (NMS) for executive function/attention/language/ visuospatial skill, and total score (TS)]. Serum manganese × APOE4 interaction had a significant effect on EMS and TS. Serum manganese level was inversely associated with EMS and TS in APOE4-positive but not APOE4-negative participants. APOE4 should be considered a key component in Alzheimer's disease studies that included manganese imbalance as a risk factor.

Ginseng intake and Alzheimer disease-specific cognition in older adults according to apolipoprotein ε4 allele status.

Background: The probable association among ginseng intake, Alzheimer's disease (AD)-specific cognition, and apolipoprotein ε4 (APOE4) remains poorly investigated. Hence, we examined the association between ginseng intake and AD-specific cognition in older adults under the moderating effect of APOE4 status. Methods: This study enrolled 160 adults aged 65-90 years without dementia. All participants underwent comprehensive dietary and clinical assessments including ginseng intake, AD-related cognition (i.e., delayed episodic memory, as the earliest cognitive change in AD), and non-memory cognition for comparative purposes. Results: Ginseng intake was associated with higher delayed episodic memory, but not non-memory cognition, compared to no ginseng intake. The interaction between ginseng intake and APOE4 status had a significant effect on delayed episodic memory. Subgroup analyses showed that ginseng intake was associated with higher delayed episodic memory in the APOE4-negative but not the APOE4-positive subgroup. The benefits of ginseng intake on delayed episodic memory were prominent in the high duration (≥5 years) and midlife onset (<65 years) groups. Conclusion: Our study of older adults with no dementia suggests that ginseng intake (with high duration and midlife onset) had a beneficial effect on AD-specific cognitive decline, i.e., the delayed episodic memory. In addition, APOE4 status moderates the association between ginseng intake status and AD-specific cognitive decline.

Spicy food intake predicts Alzheimer-related cognitive decline in older adults with low physical activity.

A plausible association exists among spicy food consumption, physical activity, and Alzheimer's disease (AD) or cognitive decline, but it remains poorly investigated. We aimed to examined the association between spicy food and AD-related memory decline or global cognitive decline in older adults under the moderating effect of physical activity. Total 196 non-demented older adults were included. Participants underwent comprehensive dietary and clinical assessments including spicy food intake, AD-related memory, global cognition, and physical activity. The strength of spicy food was stratified into three categories: 'not spicy' (reference), 'low spiciness', and 'high spiciness'. Multiple linear regression analyses were performed to examine the relationships between spicy level and cognition. The spicy level was the independent variable in each analysis; it was entered as a stratified categorical variable using the three categories. We found a significant association between a high level of spiciness in food and decreased memory ([Formula: see text] - 0.167, p < 0.001) or global cognition ([Formula: see text] - 0.122, p = 0.027), but not non-memory cognition. To explore the moderating effects of age, sex, apolipoprotein E ε4 allele-positivity, vascular risk score, body mass index, and physical activity on the associations between spicy level and memory or global cognition, the same regression analyses were repeated including two-way interaction terms between the spicy level and each of the six variables as an additional independent variable. An interactive effect was detected between a high level of spiciness in food and physical activity on the memory ([Formula: see text] 0.209, p = 0.029) or global cognition ([Formula: see text] 0.336, p = 0.001). Subgroup analyses showed that the association between a high level of spiciness in food and a lower memory ([Formula: see text] - 0.254, p < 0.001) and global score ([Formula: see text] - 0.222, p = 0.002) was present only in older adults with low physical activity, but not in older adults with high physical activity. Our findings suggest that spicy food intake is predictive of AD-related cognitive decline, i.e., episodic memory; this relationship is worsened by physically inactive lifestyle.

High-intensity walking in midlife is associated with improved memory in physically capable older adults.

BACKGROUND: Little is known about the associations of midlife- and late life-initiated walking with Alzheimer's disease (AD)-related cognitive decline in humans. We aimed to investigate whether high-intensity, prolonged, midlife-initiated walking is associated with changes in AD-related cognitive decline in physically capable older adults. METHODS: We studied 188 physically capable participants aged 65-90 years without dementia who underwent comprehensive clinical assessment, including of their walking modality (i.e., intensity, duration, midlife- or late life-onset), memory- or non-memory and total cognitive performance, and blood or nutritional biomarkers. RESULTS: The walking group showed better episodic memory (B = 2.852, SE = 1.214, ß = 0.144, p = 0.020), but not non-memory cognition, than the non-walking group. High-intensity walking starting in midlife was significantly associated with better episodic memory (B = 9.360, SE = 3.314, ß = 0.446, p = 0.005) compared to the non-walking group. In contrast, there were no differences in cognition according to walking duration, regardless of the onset time. The walking group also showed a similar association with overall cognition. CONCLUSIONS: Among physically capable older adults without dementia, walking, particularly at high intensity and starting in midlife, is associated with improved episodic memory, an AD-related cognitive domain. Further attention should be paid to the role of walking in terms of AD prevention.

Association of a History of Sleep Disorder With Risk of Mild Cognitive Impairment and Alzheimer's Disease Dementia.

OBJECTIVE: We explored whether a history of sleep disorder affected a current diagnosis of cognitive impairment and clinical conversion in a non-demented elderly population. METHODS: Comprehensive clinical data collected as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI) was analyzed. A history of sleep disorder was recorded in the recent ADNI medical database. Standard clinical and neuropsychological tests were performed both at baseline and follow-up visit. Multiple logistic regression analysis was performed after adjusting for age, sex, education, apolipoprotein E ε4 status, vascular risk score, body mass index, Geriatric Depression Scale score, and use of sleeping pills. RESULTS: A total of 391 cognitively normal individuals, 303 with early mild cognitive impairment (MCI) and 364 with late MCI were included. Sleep disorder history was significantly associated with an increased risk of MCI but not with clinical conversion. A history of insomnia or obstructive sleep apnea (OSA) significantly increased the risk of MCI, but only an OSA history predicted progression to Alzheimer's disease (AD) dementia. CONCLUSION: Our findings suggest that a sleep disorder history usefully aids early detection of cognitive impairment and emphasize that such sleep disorder, particularly OSA, is important as potential target for AD prevention.

Association Between Copper and Global Cognition and the Moderating Effect of Iron.

Background: Despite the known association between abnormal serum copper levels and Alzheimer's disease (AD) or cognitive decline, the association between copper, iron, and cognition remains poorly investigated. We examined the association between serum copper levels and global cognition measured using the Mini-Mental State Examination (MMSE) in older adults with normal copper levels. We also explored the moderating effect of iron on this association. Methods: The study enrolled 99 non-demented adults between 65 and 90 years of age. All the participants underwent comprehensive clinical assessments and serum copper measurements. Global cognitive performance was measured by the MMSE. All copper levels were within the normal range and were stratified into three categories: < 87 (low), 87-98 (medium), and > 98 (high: used as a reference category) µg/dL. Results: Serum copper level (as a continuous variable) was significantly associated with MMSE score (B = 0.065, 95% confidence interval = 0.023-0.108, p = 0.003). Low serum copper group showed significantly decreased MMSE score compared to high copper one (B = -2.643, 95% confidence interval = -4.169 to -1.117, p < 0.001), while middle copper category had no difference (B = -1.211, 95% confidence interval = -2.689 to 0.268, p = 0.107). There was a significant low serum copper ×iron interaction effect on the MMSE score (B = 0.065, 95% confidence interval = 0.016-0.114, p = 0.010). Subgroup analyses showed that low serum copper was significantly associated with a low MMSE score in the low-iron (B = -4.174, 95% confidence interval = -6.607 to -1.741, p = 0.001) but not high-iron subgroup (B = -0.721, 95% confidence interval = -2.852 to 1.409, p = 0.495). Conclusion: Our findings from non-demented older adults suggest that a low serum copper level within the normal range was associated with AD or cognitive decline and this is moderated by iron. To prevent AD or cognitive decline, clinicians need to pay attention to avoiding low serum copper and iron levels, even within the clinical normal range.

Brain Amyloid Index as a Probable Marker Bridging Between Subjective Memory Complaint and Objective Cognitive Performance.

Background: The association between types of subjective memory complaint (SMC), poor objective cognitive performance, and brain Aß deposition have been poorly understood. We investigated the association between types of SMC and objective global cognitive performance, then assessed whether this association is mediated by the brain amyloid prediction index (API). Methods: In total, 173 non-demented older adults [63 cognitively normal (CN) and 110 mild cognitive impairment (MCI)] underwent comprehensive clinical assessments. Objective global cognitive performance and brain amyloid index were measured using the total score (TS) of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery and API, respectively. In total, four items of SMC from the subjective memory complaints questionnaire (SMCQ) (SMCQ1: a feeling of memory problem; SMCQ2: the feeling of worse memory than 10 years ago; SMCQ3: the feeling of worse memory than others of similar age; or SMCQ4: the feeling of difficulty in everyday life) in global memory function were assessed. Results: In non-demented and participants with MCI, SMCQ3-positive and SMCQ4-positive groups were associated with decreased TS. In participants with MCI, the SMCQ3-positive group was associated with increased API, and API was associated with decreased TS, but the SMCQ4-positive group did not. In addition, the association between the SMCQ3-positive group and poor TS disappeared when API was controlled as a covariate, indicating that API has a mediation effect. Conclusion: The present findings suggest that SMC, a feeling of worse memory performance than others in a similar age group, in the older adults without dementia is associated with poor objective cognitive performance via increased brain amyloid index.

Association Between Enlarged Perivascular Spaces and Cognition in a Memory Clinic Population.

BACKGROUND AND OBJECTIVES: Although enlarged perivascular spaces (EPVS) have been suggested as an emerging measure of small vessel disease (SVD) in the brain, their association with cognitive impairment is not yet clearly understood. We aimed to examine the relationship between each EPVS in the basal ganglia (BG-EPVS) and centrum semiovale (CSO-EPVS) with cognition in a memory clinic population. METHODS: Participants with a diverse cognitive spectrum were recruited from a university hospital memory clinic. They underwent comprehensive clinical and neuropsychological assessments and brain MRI. BG-EPVS and CSO-EPVS were measured on T2-weighted MRI and then dichotomized into low and high degrees for further analyses. Other SVD markers were assessed using validated rating scales. RESULTS: A total of 910 participants were included in this study. A high degree of BG-EPVS was significantly associated with poorer scores on the executive function domain, but not with other cognitive domains, when age, sex, education, MRI scanner type, and cognitive diagnosis were controlled as covariates. However, the association between BG-EPVS and executive function was no longer significant after controlling for other markers of SVD, such as lacunar infarcts and periventricular white matter hyperintensities, as additional covariates. CSO-EPVS did not have a significant relationship with any cognitive scores, regardless of the covariates. DISCUSSION: Our findings from a large memory clinic population suggest that EPVS, regardless of the topographical location, may not be used as a specific SVD marker for cognitive impairment, although an apparent association was observed between a high degree of BG-EPVS and executive dysfunction before controlling other SVD markers that share a common pathophysiologic process with BG-EPVS.

A combination of midlife diabetes mellitus and the apolipoprotein E ε4 allele increase risk for cognitive decline.

Background: It has been suggested that diabetes mellitus (DM) and the apolipoprotein E (APOE) ε4 allele (APOE4) increase the risk for Alzheimer's disease (AD) and cognitive decline. However, the evidence is sparse. We explored whether APOE4 status modulated the effects of midlife and late-life DM on global cognition of non-demented older adults. Methods: In all, 176 non-demented adults (age 65-90 years) were enrolled. All the participants underwent comprehensive clinical assessments including midlife and late-life DM evaluation and APOE genotyping. The global cognitive performance index was assessed by the total score (TS) of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery. Results: We found a significant midlife DM × APOE4 interaction effect on the global cognitive performance. Subgroup analyses indicated that an association between midlife DM and decreased global cognitive performance was apparent only in older adults who were APOE4-positive, and not in those with APOE4-negative. Conclusion: Our findings from non-demented older adults suggest that midlife DM increases the risk for AD and cognitive decline, and this risk is modulated by APOE4 status. To prevent AD and cognitive decline, physicians should check for the possible coexistence of midlife DM and APOE4-positive status.