To determine whether higher adherence to a Mediterranean-type diet (MeDi) is related with larger MRI-measured brain volume or cortical thickness.
In this cross-sectional study, high-resolution ...structural MRI was collected on 674 elderly (mean age 80.1 years) adults without dementia who participated in a community-based, multiethnic cohort. Dietary information was collected via a food frequency questionnaire. Total brain volume (TBV), total gray matter volume (TGMV), total white matter volume (TWMV), mean cortical thickness (mCT), and regional volume or CT were derived from MRI scans using FreeSurfer program. We examined the association of MeDi (scored as 0-9) and individual food groups with brain volume and thickness using regression models adjusted for age, sex, ethnicity, education, body mass index, diabetes, and cognition.
Compared to lower MeDi adherence (0-4), higher adherence (5-9) was associated with 13.11 (p = 0.007), 5.00 (p = 0.05), and 6.41 (p = 0.05) milliliter larger TBV, TGMV, and TWMV, respectively. Higher fish (b = 7.06, p = 0.006) and lower meat (b = 8.42, p = 0.002) intakes were associated with larger TGMV. Lower meat intake was also associated with larger TBV (b = 12.20, p = 0.02). Higher fish intake was associated with 0.019 mm (p = 0.03) larger mCT. Volumes of cingulate cortex, parietal lobe, temporal lobe, and hippocampus and CT of the superior-frontal region were associated with the dietary factors.
Among older adults, MeDi adherence was associated with less brain atrophy, with an effect similar to 5 years of aging. Higher fish and lower meat intake might be the 2 key food elements that contribute to the benefits of MeDi on brain structure.
Introduction
Low vitamin D intake and low vitamin D circulating levels have been associated with increased risk for dementia. We aimed to examine the association between vitamin D intake and dementia ...in a multiethnic cohort.
Methods
A longitudinal study of 1759 non‐demented older (≥65 years) participants of the Washington Heights‐Inwood Columbia Aging Project with follow‐up visits and completed a food frequency questionnaire. Dementia was diagnosed by consensus using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) criteria. Cox hazard regression was performed.
Results
During a mean follow‐up of 5.8 years, 329 participants developed dementia. Participants with the highest tertile of vitamin D intake from food sources had decreased risk (hazard ratio HR 0.72, 95% confidence interval CI 0.54–0.97, P = .030) for dementia compared with those with the lowest tertile, adjusting for age, sex, race/ethnicity, education, apolipoprotein E (APOE)‐ε4, physical activity, Mediterranean diet (MeDI) score, income, depression, hypertension, diabetes, cardiovascular disease, and smoking.
Discussion
Higher vitamin D intake is associated with decreased risk of dementia in a multiethnic cohort.
To study biomarkers of inflammation in cerebrovascular disease, exploring modifiable and non-modifiable biochemical and clinical risk factors associated with the presence of intracranial saccular ...aneurysms (ISAs) in an HIV-positive cohort.
A cross-sectional community-based study was used to study blood biomarkers of inflammation as predictors of cerebrovascular disease, specifically the presence of ISAs in persons with HIV. Potential biochemical and clinical predictors of ISA presence were identified.
Time of flight magnetic resonance angiography and magnetic resonance imaging data identified the presence of ISAs in an HIV-positive cohort. Quantitative assays for neuroinflammatory biomarkers were performed on plasma blood samples. Lasso regression models were used to identify neuroinflammatory biomarkers and clinical risk factors associated with ISAs.
Eight of 72 participants had radiographically identified ISAs. ISAs were more common in non-Hispanic black participants (18.5% vs. 0% presence in nonblack patients). Participants with well controlled HIV (defined as CD4+ count >200 cells/ml and undetectable viral load at time of magnetic resonance imaging) had lower odds of ISAs (odds ratio: 0.19, 95% confidence interval 0.05-0.79) independent of age, sex, ethnicity and vascular risk factors. Macrophage inflammatory protein-1 p, an HIV- suppressive factor detected in participant blood samples, was inversely associated with aneurysm presence.
Well controlled HIV is associated with fewer ISAs. The identification of non-modifiable and modifiable risk factors contributing to ISA formation may provide valuable insight to impact clinical practice and inform the pathophysiology underlying ISA formation.
Abstract Introduction It is unclear whether white matter hyperintensities (WMHs), magnetic resonance imaging markers of small-vessel cerebrovascular disease, promote neurodegeneration and associated ...clinical decline in Alzheimer's disease (AD), or simply co-occur with recognized pathogenic processes. Methods In 169 patients with mild cognitive impairment, followed for 3 years, we examined the association of (1) baseline regional WMH and cerebral spinal fluid–derived t-tau (total tau) with entorhinal cortex atrophy rates, as a marker of AD-related neurodegeneration, and conversion to AD; and (2) baseline regional WMH with change in t-tau level. Results In participants with low baseline t-tau, higher regional WMH volumes were associated with faster entorhinal cortex atrophy. Higher parietal WMH volume predicted conversion to AD in those with high t-tau. Higher parietal and occipital WMH volumes predicted increasing t-tau. Discussion WMHs affect AD clinical and pathologic processes both directly and interacting with tau.
To investigate default mode network (DMN) functional connectivity MRI (fcMRI) in a large cross-sectional cohort of subjects from families harboring pathogenic presenilin-1 (PSEN1), presenilin-2 ...(PSEN2), and amyloid precursor protein (APP) mutations participating in the Dominantly Inherited Alzheimer Network.
Eighty-three mutation carriers and 37 asymptomatic noncarriers from the same families underwent fMRI during resting state at 8 centers in the United States, United Kingdom, and Australia. Using group-independent component analysis, fcMRI was compared using mutation status and Clinical Dementia Rating to stratify groups, and related to each participant's estimated years from expected symptom onset (eYO).
We observed significantly decreased DMN fcMRI in mutation carriers with increasing Clinical Dementia Rating, most evident in the precuneus/posterior cingulate and parietal cortices (p < 0.001). Comparison of asymptomatic mutation carriers with noncarriers demonstrated decreased fcMRI in the precuneus/posterior cingulate (p = 0.014) and right parietal cortex (p = 0.0016). We observed a significant interaction between mutation carrier status and eYO, with decreases in DMN fcMRI observed as mutation carriers approached and surpassed their eYO.
Functional disruption of the DMN occurs early in the course of autosomal dominant Alzheimer disease, beginning before clinically evident symptoms, and worsening with increased impairment. These findings suggest that DMN fcMRI may prove useful as a biomarker across a wide spectrum of disease, and support the feasibility of DMN fcMRI as a secondary endpoint in upcoming multicenter clinical trials in Alzheimer disease.
Abstract
Background
Age-related hearing loss (HL), a common and treatable condition, has been associated with other age-related conditions. Late life cognitive impairment is a major public health ...concern that is rarely treatable. Studies examining the relationship between HL and cognition have been limited by non-Hispanic cohorts, small samples, or limited confounding control. We overcome these limitations in a large Hispanic cohort.
Methods
This was a multisite cross-sectional study of 5,277 subjects at least 50 years old (Hispanic Community Health Study, HCHS). The main exposure was audiometric HL. The main outcome measure was neurocognitive performance ascertained by the Digit Symbol Substitution Test (DSST), Word Frequency Test, Spanish-English Verbal Learning Test (SEVLT), and Six-Item Screener.
Results
The mean age was 58.4 years (SD = 6.2). A 20-dB (equivalent to a one-category worsening) increase in HL was associated with a −1.53 (95% CI, −2.11, −0.94) raw score point difference in the DSST, adjusting for demographics, hearing aid use, and cardiovascular disease. Similarly, a 20-dB increase in HL was associated with a −0.86 (−1.23, −0.49) point difference on the Word Frequency Test, −0.76 (−1.04, −0.47) on the SEVLT 3 trials, −0.45 (−0.60, −0.29) on the SELVT recall, and −0.07 (−0.12, −0.02) on the Six-Item Screener.
Conclusions
In the largest study of formal, audiometric HL and cognition to date, HL was independently associated with worse performance in a range of neurocognitive measures. Because HL is common and potentially treatable, it should be investigated as a modifiable risk factor for neurocognitive decline and dementia.
Considerable evidence has established the importance of specific nutrients that have been found vital for the developing brain. We hypothesize that in a similar manner there should be nutrients vital ...to the aging brain and that based on aging's distinct pathophysiology they should be different than those essential to development. Specific brain networks that govern cognition are particularly vulnerable to the aging process, resulting in what is referred to as ‘cognitive aging’. Common late-life disorders, however, such as Alzheimer's disease also target these same brain networks. Studies have disambiguated cognitive aging from late-life disease by isolating regions and biological pathways within each network differentially linked to one or the other. This anatomical biology anchors a framework to identify nutrients and/or dietary bioactives relevant to cognitive aging whose utility is illustrated via a decades-long research program into how dietary bioactive flavanols benefit the brain. As we are living longer in cognitively more demanding lives, the framework's ultimate goal is to generate specific dietary recommendations that will fortify our mind for its golden years.
Although white matter hyperintensities (WMHs) are associated with the risk for Alzheimer disease, it is unknown whether they represent an independent source of impairment or interact with known ...markers of disease.
To examine the degree to which WMHs predict aggressive cognitive decline among individuals with mild cognitive impairment, either independently or by modifying the effects of entorhinal cortex volume (ECV), a marker of Alzheimer disease-related neurodegeneration.
The Alzheimer's Disease Neuroimaging Initiative is a longitudinal study with 6-month follow-up visits. Three hundred thirty-two participants (mean SD age, 74.6 7.4 years; 118 women) of a total of 374 participants diagnosed as having mild cognitive impairment were included. Participants were excluded if they did not have longitudinal data, apolipoprotein E genotype data, or had evidence of supratentorial infarct.
A decline in Mini-Mental State Examination score of 3 points over 6 months or 6 points over 1 year between consecutive visits was defined as aggressive decline. White matter hyperintensity volume and ECV were entered as predictors in Cox proportional hazards models and Wilcoxon-Breslow tests to examine their impact on this outcome, adjusting for sex, age, education, and apolipoprotein E status.
Greater WMH volume at baseline, apolipoprotein E ε4 status, and smaller ECV at baseline were associated with an increased risk for aggressive decline (hazard ratio HR, 1.23; 95% CI, 1.05-1.43; P = .01 for WMH volume; HR, 1.49; 95% CI, 1.09-2.05; P = .04 for apolipoprotein E ε4 status; HR, 0.66; 95% CI, 0.55-0.79; P < .001 for ECV). White matter hyperintensity volume modified the effect of ECV on aggressive decline risk: individuals with high ECV and low WMH were at particularly low likelihood of decline (χ2 = 15, P = .001). Participants with Mini-Mental State Examination scores that declined by 3 or more points over 6 months or 6 or more points over 12 months were more likely to have converted to Alzheimer disease by the end of the follow-up period (χ2 = 82, P < .001).
White matter hyperintensity burden and ECV predict rapid cognitive decline among individuals with mild cognitive impairment both additively and multiplicatively.
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