Mosley, Thomas H.

Alzheimer's disease (AD) is the most common form of dementia and is characterized by impairment in memory, behavioral changes, and gradual loss of autonomy. Since there is a long latent period prior to diagnosis, the aim of this study was to determine whether twenty single nucleotide polymorphisms identified in genome‐wide association analyses of AD are associated with cognitive change in 8,320 white and 2,039 African‐American middle‐aged adults enrolled in the prospective Atherosclerosis Risk in Communities (ARIC) study. Cognition was evaluated using the Delayed Word Recall Test (DWRT; verbal memory), Digit Symbol Substitution Test (DSST; processing speed), and Word Fluency Test (WFT; executive function). General linear models were used to assess mean differences in 6‐year change in test scores among individuals categorized by genotype after adjusting for age, gender, and years of education. Addition of the minor allele for rs670139 (MS4A4E), rs9331896 (CLU), and rs12155159 (NME8) was nominally associated with change on the DWRT, DSST, and WFT, respectively, in whites. The ZCWPW1(rs1476679) andCDS33(rs3865444) variants were nominally associated with change on the DWRT and WFT in African‐Americans. For rs670139 and rs9331896 the association was only significant in individuals bearing at least oneAPOEϵ4 allele in stratified analyses. An unweighted genetic risk score aggregating the risk alleles for 15 polymorphisms was not associated with change in cognitive function. Although the AD‐associated genetic variants appear to have small effects on early cognitive change, replication will be required to establish whether there is a discernible influence on cognitive status in midlife. © 2016 Wiley Periodicals, Inc.

Objectives To quantify associations between inflammatory biomarkers and hippocampal volume ( HV ) and to examine effect modification according to sex, race, and age. Design Cross‐sectional analyses using generalized estimating equations to account for familial clustering; standardized β ‐coefficients adjusted for age, sex, race, and education. Setting Community cohorts in Jackson, Mississippi and Rochester, Minnesota. Participants The Genetic Epidemiology Network of Arteriopathy study. Measurements C‐reactive protein ( CRP ), interleukin‐6 ( IL ‐6), and soluble tumor necrosis factor receptors 1 ( sTNFR ‐1) and 2 ( sTNFR ‐2) from peripheral blood were measured in a sample of 773 non‐Hispanic whites (61% women, aged 60.2 ± 9.8) and 514 African Americans (70% women, aged 63.9 ± 8.1) who also underwent brain magnetic resonance imaging. Biomarkers were standardized and compared according to sex, race and age with HV. Results In the full sample, higher sTNFR ‐1 and sTNFR ‐2 were associated with smaller HV . Each standard deviation ( SD ) increase in sTNFR ‐1 was associated with 59.1 mm 3 (95% confidence interval ( CI ) = −101.4 to −16.7 mm 3 ) smaller HV and each SD increase in sTNFR ‐2 associated with 48.8 mm 3 (95% CI = −92.2 to −5.3 mm 3 ) smaller HV . Relationships were stronger for sTNFR ‐2 in men ( HV = −116.6 mm 3 for each SD increase, 95% CI = −201.0 to −32.1) than women ( HV = −26.0 per SD increase, 95% CI = −72.4–20.5) and sTNFR ‐1 in non‐Hispanic whites ( HV = −84.7 mm 3 per SD increase, 95% CI = −142.2 to −27.1) than African Americans ( HV = −14.1 mm 3 per SD increase, 95% CI = −78.3–50.1). Associations between IL ‐6 or CRP and HV were not supported. Conclusion Higher levels of sTNFR s were associated cross‐sectionally with smaller hippocampi. Longitudinal data are needed to determine whether these biomarkers may help to identify risk of late‐life cognitive impairment.

Objectives To examine associations between inflammation and physical function and potential mediation by white matter hyperintensities ( WMH s) in African Americans ( AA s) and European Americans ( EA s). Design Cross‐sectional analysis using linear and logistic models with generalized estimating equations to account for family clustering, reporting results as regression coefficients (β) and odds ratios ( OR s) adjusted for education, alcohol, exercise, body mass index, hypertension, diabetes mellitus, heart disease, cognition, ankle–brachial index, race (site), and supported interactions. Setting Genetic Epidemiology Network of Arteriopathy‐Genetics of Microangiopathic Brain Injury Study cohort. Participants AA and EA sibships with two or more siblings with hypertension before age 60 (N = 1,960; 65% female, 51% AA , aged 26–91, 50% obese, 72% hypertensive). Measurements Inflammation (C‐reactive protein ( CRP ), interleukin‐6 ( IL 6), soluble tumor necrosis factor receptors ( sTNFR s) 1 and 2, WMH volume (cm 3 ) according to magnetic resonance imaging), walking speed (cm/s) over 25 feet, and mobility difficulty (any self‐reported difficulty walking half a mile). Results In separate models, inflammatory markers were associated with walking speed ( sTNFR 1: β = −2.74, P < .001; sTNFR 2: β = −1.23, P = .03; CRP : β = −1.95, P = .001; IL 6: β = −1.24, P = .03) and mobility difficulty ( sTNFR 1: OR = 1.36, P = .001; sTNFR 2: OR = 1.25, P = .005; CRP : OR = 1.22, P = .005; IL 6: OR = 1.18, P = .02); the association between WMH volume and sTNFR 1 in AA (β = 0.07, P = .06) did not reach typical statistical thresholds. WMH volume was associated with walking speed in AA (β = −3.17, P = .02) but not with mobility difficulty ( OR = 1.10, P = .54). Adjusting for WMH did not change associations. Conclusion In young, middle‐aged, and older adults with prevalent cardiovascular risk factors, multiple inflammatory biomarkers were associated with slower walking speed independent of microvascular disease in the brain. There was little evidence of mediation by brain WMH volume. Inflammation may contribute to physical function impairments through pathways other than brain microvascular disease, particularly in AA s.

AbstractIntroductionPhospholipids are altered in brains of patients with dementia and some studies suggest their plasma levels may be useful in the detection of mild cognitive impairment (MCI) and dementia.MethodsWe measured 188 plasma metabolites in participants who underwent a detailed neuropsychological assessment and classified as normal (n = 153), MCI (n = 145), or dementia (n = 143) by expert adjudication.ResultsAmong 10 phospholipids recently implicated as altered in dementia, higher concentration of PC aa C36:6 was significantly associated with decreased prevalence of dementia (odds ratio = 0.71, 95% confidence interval = 0.50–1.00 per 1−SD increase). Adding these phospholipids to a model including multiple predictors of dementia led to only minimal improvement in detection (C statistic changed from 0.702 to 0.71).DiscussionSome phospholipids and metabolites were altered in MCI and dementia but cross‐sectional association was relatively weak and did not improve detection of MCI and dementia beyond information provided by clinical variables.

AbstractIntroductionThe impact of blood pressure on brain volumes may be time‐dependent or pattern‐dependent.MethodsOf 1678 participants from the Atherosclerosis Risk in Communities Neurocognitive Study, we quantified the association between measures and patterns of blood pressure over three time points (∼24 or ∼15 years prior and concurrent with neuroimaging) with late life brain volumes.ResultsHigher diastolic blood pressure ∼24 years prior, higher systolic and pulse pressure ∼15 years prior, and consistently elevated or rising systolic blood pressure from ∼15 years prior to concurrent with neuroimaging, but not blood pressures measured concurrent with neuroimaging, were associated with smaller volumes. The pattern of hypertension ∼15 years prior and hypotension concurrent with neuroimaging was associated with smaller volumes in regions preferentially affected by Alzheimer's disease (e.g., hippocampus: −0.27 standard units, 95% CI: −0.51, −0.03).DiscussionHypertension 15 to 24 years prior is relevant to current brain volumes. Hypertension followed by hypotension appears particularly detrimental.

Background— Hypertensive pregnancy disorders have been associated with subjective cognitive complaints or brain white-matter lesions 5 to 10 years after the hypertensive pregnancy. The long-term effects of hypertensive pregnancies on brain structure and cognitive function remain unknown. Methods and Results— This study included 1279 women who participated in the Family Blood Pressure Project Genetic Epidemiology Network of Arteriopathy (GENOA) study. As part of the ancillary Genetics of Microangiopathic Brain Injury (GMBI) study, a neurocognitive battery was administered; 1075 also had a brain magnetic resonance imaging. A history of a hypertensive pregnancy disorder was obtained by a self-report using a validated questionnaire. Linear models fit with generalized estimating equations were used to assess the association between hypertensive pregnancy disorders and cognition, adjusting for age, race, education, body mass index, smoking, current hypertension, hypertension duration, and family history of hypertension. Regression models for the brain magnetic resonance imaging outcomes also were adjusted for total intracranial volume. Women with histories of hypertensive pregnancy disorders performed worse on all measures of processing speed (Digital Symbol Substitution Test [mean score, 41.2 versus 43.4; P =0.005], Trail Making Test Part A [mean seconds, 45.1 versus 42.2; P =0.035], and Stroop [mean score, 173.9 versus 181.0; P =0.002]) and had smaller brain volumes compared with women with histories of normotensive pregnancies (286 versus 297; P =0.023). Conclusions— Hypertensive pregnancy disorders are associated with worse performance on tests of processing speed and smaller brain volumes decades later. Population-based studies are needed to provide critical insight as to the contribution of hypertensive pregnancies to risk of cognitive decline and dementia.

AbstractIntroductionWe examined prevalence of mild cognitive impairment (MCI) and dementia in the Atherosclerosis Risk in Communities (ARIC) Neurocognitive study.MethodsBeginning in June, 2011, we invited all surviving ARIC participants to undergo cognitive, neurologic, and brain imaging assessments to diagnose MCI or dementia and assign an etiology for the cognitive disorder.ResultsOf 10,713 surviving ARIC participants (age range, 69–88 years), we ascertained cognitive diagnoses in 6471 in person, 1966 by telephone interviews (participant or informant), and the remainder by medical record review. The prevalence of dementia was 9.0% and MCI 21%. Alzheimer's disease (AD) was the primary or secondary etiology in 76% of dementia and 75% of MCI participants. Cerebrovascular disease was the primary or secondary etiology in 46% of dementia and 32% of MCI participants.DiscussionMCI and dementia were common among survivors from the original ARIC cohort. Nearly 30% of the ARIC cohort received diagnoses of either dementia or MCI, and for the majority of these individuals, the etiologic basis was attributed to AD.

Objective Cardiac changes of hypertensive pregnancy include left ventricular hypertrophy (LVH) and diastolic dysfunction. These are thought to regress postpartum. We hypothesised that women with a history of hypertensive pregnancy would have altered LV geometry and function when compared with women with only normotensive pregnancies. Methods In this cohort study, we analysed echocardiograms of 2637 women who participated in the Family Blood Pressure Program. We compared LV mass and function in women with hypertensive pregnancies with those with normotensive pregnancies. Results Women were evaluated at a mean age of 56 years: 427 (16%) had at least one hypertensive pregnancy; 2210 (84%) had normotensive pregnancies. Compared with women with normotensive pregnancies, women with hypertensive pregnancy had a greater risk of LVH (OR: 1.42; 95% CI 1.01 to 1.99, p=0.05), after adjusting for age, race, research network of the Family Blood Pressure Program, education, parity, BMI, hypertension and diabetes. When duration of hypertension was taken into account, this relationship was no longer significant (OR: 1.19; CI 0.08 to 1.78, p=0.38). Women with hypertensive pregnancies also had greater left atrial size and lower mitral E/A ratio after adjusting for demographic variables. The prevalence of systolic dysfunction was similar between the groups. Conclusions A history of hypertensive pregnancy is associated with LVH after adjusting for risk factors; this might be explained by longer duration of hypertension. This finding supports current guidelines recommending surveillance of women following a hypertensive pregnancy, and sets the stage for longitudinal echocardiographic studies to further elucidate progression of LV geometry and function after pregnancy. Clinical trial registrations GENOA- NCT00005269; HyperGEN- NCT00005267; Sapphire- NCT00005270; GenNet- NCT00005268.