Association of plasma biomarkers with cognition, cognitive decline, and daily function across and within neurodegenerative diseases: Results from the Ontario Neurodegenerative Disease Research Initiative.

INTRODUCTION: We investigated whether novel plasma biomarkers are associated with cognition, cognitive decline, and functional independence in activities of daily living across and within neurodegenerative diseases. METHODS: Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated tau (p-tau)181 and amyloid beta (Aß)42/40 were measured using ultra-sensitive Simoa immunoassays in 44 healthy controls and 480 participants diagnosed with Alzheimer's disease/mild cognitive impairment (AD/MCI), Parkinson's disease (PD), frontotemporal dementia (FTD) spectrum disorders, or cerebrovascular disease (CVD). RESULTS: GFAP, NfL, and/or p-tau181 were elevated among all diseases compared to controls, and were broadly associated with worse baseline cognitive performance, greater cognitive decline, and/or lower functional independence. While GFAP, NfL, and p-tau181 were highly predictive across diseases, p-tau181 was more specific to the AD/MCI cohort. Sparse associations were found in the FTD and CVD cohorts and for Aß42/40 . DISCUSSION: GFAP, NfL, and p-tau181 are valuable predictors of cognition and function across common neurodegenerative diseases, and may be useful in specialized clinics and clinical trials.

Longitudinal cerebral perfusion in presymptomatic genetic frontotemporal dementia: GENFI results.

INTRODUCTION: Effective longitudinal biomarkers that track disease progression are needed to characterize the presymptomatic phase of genetic frontotemporal dementia (FTD). We investigate the utility of cerebral perfusion as one such biomarker in presymptomatic FTD mutation carriers. METHODS: We investigated longitudinal profiles of cerebral perfusion using arterial spin labeling magnetic resonance imaging in 42 C9orf72, 70 GRN, and 31 MAPT presymptomatic carriers and 158 non-carrier controls. Linear mixed effects models assessed perfusion up to 5 years after baseline assessment. RESULTS: Perfusion decline was evident in all three presymptomatic groups in global gray matter. Each group also featured its own regional pattern of hypoperfusion over time, with the left thalamus common to all groups. Frontal lobe regions featured lower perfusion in those who symptomatically converted versus asymptomatic carriers past their expected age of disease onset. DISCUSSION: Cerebral perfusion is a potential biomarker for assessing genetic FTD and its genetic subgroups prior to symptom onset. HIGHLIGHTS: Gray matter perfusion declines in at-risk genetic frontotemporal dementia (FTD). Regional perfusion decline differs between at-risk genetic FTD subgroups . Hypoperfusion in the left thalamus is common across all presymptomatic groups. Converters exhibit greater right frontal hypoperfusion than non-converters past their expected conversion date. Cerebral hypoperfusion is a potential early biomarker of genetic FTD.

Genome-wide meta-analyses reveal novel loci for verbal short-term memory and learning.

Understanding the genomic basis of memory processes may help in combating neurodegenerative disorders. Hence, we examined the associations of common genetic variants with verbal short-term memory and verbal learning in adults without dementia or stroke (N = 53,637). We identified novel loci in the intronic region of CDH18, and at 13q21 and 3p21.1, as well as an expected signal in the APOE/APOC1/TOMM40 region. These results replicated in an independent sample. Functional and bioinformatic analyses supported many of these loci and further implicated POC1. We showed that polygenic score for verbal learning associated with brain activation in right parieto-occipital region during working memory task. Finally, we showed genetic correlations of these memory traits with several neurocognitive and health outcomes. Our findings suggest a role of several genomic loci in verbal memory processes.

Cerebral perfusion changes in presymptomatic genetic frontotemporal dementia: a GENFI study.

Genetic forms of frontotemporal dementia are most commonly due to mutations in three genes, C9orf72, GRN or MAPT, with presymptomatic carriers from families representing those at risk. While cerebral blood flow shows differences between frontotemporal dementia and other forms of dementia, there is limited evidence of its utility in presymptomatic stages of frontotemporal dementia. This study aimed to delineate the cerebral blood flow signature of presymptomatic, genetic frontotemporal dementia using a voxel-based approach. In the multicentre GENetic Frontotemporal dementia Initiative (GENFI) study, we investigated cross-sectional differences in arterial spin labelling MRI-based cerebral blood flow between presymptomatic C9orf72, GRN or MAPT mutation carriers (n = 107) and non-carriers (n = 113), using general linear mixed-effects models and voxel-based analyses. Cerebral blood flow within regions of interest derived from this model was then explored to identify differences between individual gene carrier groups and to estimate a timeframe for the expression of these differences. The voxel-based analysis revealed a significant inverse association between cerebral blood flow and the expected age of symptom onset in carriers, but not non-carriers. Regions included the bilateral insulae/orbitofrontal cortices, anterior cingulate/paracingulate gyri, and inferior parietal cortices, as well as the left middle temporal gyrus. For all bilateral regions, associations were greater on the right side. After correction for partial volume effects in a region of interest analysis, the results were found to be largely driven by the C9orf72 genetic subgroup. These cerebral blood flow differences first appeared approximately 12.5 years before the expected symptom onset determined on an individual basis. Cerebral blood flow was lower in presymptomatic mutation carriers closer to and beyond their expected age of symptom onset in key frontotemporal dementia signature regions. These results suggest that arterial spin labelling MRI may be a promising non-invasive imaging biomarker for the presymptomatic stages of genetic frontotemporal dementia.

Brain Volumes and Longitudinal Cognitive Change: A Population-based Study.

OBJECTIVE: To investigate the association of brain volumes, white matter lesion (WML) volumes, and lacunes, with cognitive decline in a population-based cohort of nondemented persons. METHODS: Within the Rotterdam Study, 3624 participants underwent brain magnetic resonance imaging. Cognition was evaluated at baseline (2005 to 2009) and at the follow-up visit (2011 to 2013). We used a test battery that tapped into domains of executive function, information processing speed, motor speed, and memory. The volumetric measures assessed were total brain volume, lobar (gray matter and white matter) volumes, and hippocampal volumes. We also studied the association of WML volumes and lacunes with cognitive decline using linear regression models. RESULTS: Total brain volume was associated with decline in global cognition, information processing, and motor speed (P<0.001) in analyses controlled for demographic and vascular factors. Specifically, smaller frontal and parietal lobes were associated with decline in information processing and motor speed, and smaller temporal and parietal lobes were associated with decline in general cognition and motor speed (P<0.001 for all tests). Total WML volume was associated with decline in executive function. Lobar WML volume, hippocampal volume, and lacunes were not associated with cognitive decline. CONCLUSIONS: Lower brain volume is associated with subsequent cognitive decline. Although lower total brain volume was significantly associated with decline in global cognition, specific lobar volumes were associated with decline in certain cognitive domains.

APOE-ε4 associates with hippocampal volume, learning, and memory across the spectrum of Alzheimer's disease and dementia with Lewy bodies.

INTRODUCTION: Although the apolipoprotein E ε4-allele (APOE-ε4) is a susceptibility factor for Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), its relationship with imaging and cognitive measures across the AD/DLB spectrum remains unexplored. METHODS: We studied 298 patients (AD = 250, DLB = 48; 38 autopsy-confirmed; NCT01800214) using neuropsychological testing, volumetric magnetic resonance imaging, and APOE genotyping to investigate the association of APOE-ε4 with hippocampal volume and learning/memory phenotypes, irrespective of diagnosis. RESULTS: Across the AD/DLB spectrum: (1) hippocampal volumes were smaller with increasing APOE-ε4 dosage (no genotype × diagnosis interaction observed), (2) learning performance as assessed by total recall scores was associated with hippocampal volumes only among APOE-ε4 carriers, and (3) APOE-ε4 carriers performed worse on long-delay free word recall. DISCUSSION: These findings provide evidence that APOE-ε4 is linked to hippocampal atrophy and learning/memory phenotypes across the AD/DLB spectrum, which could be useful as biomarkers of disease progression in therapeutic trials of mixed disease.

Mild cognitive impairment and risk of depression and anxiety: A population-based study.

INTRODUCTION: Many people with mild cognitive impairment (MCI) suffer from concomitant depression or anxiety. Whether MCI increases the risk of future depression or anxiety is unknown. METHODS: In the Rotterdam Study, cross-sectional (n = 4168) and longitudinal associations (n = 2967) of MCI with Diagnostic and Statistical Manual of Mental Disorders-depressive and anxiety disorders-were assessed (2002-2005 to 2009-2011). RESULTS: At baseline, 413 persons had MCI; 125 (22 MCI and 103 non-MCI) had a depressive disorder and 330 had an anxiety disorder (46 MCI and 284 non-MCI). In longitudinal depression analysis, of the 212 persons with prevalent MCI, 6 (2.8%) developed depression compared with 29 (1%) in the nonexposed group. In longitudinal anxiety analysis, 11 (7.3%) of the 151 with prevalent MCI developed anxiety, compared with 75 (3.4%) in nonexposed group. Persons with MCI had more depressive and anxiety disorders and also a higher risk of developing depressive disorder, odds ratio (OR) 3.13 (95% confidence interval [CI]: 1.26, 7.77), and anxiety disorder, OR 2.59 (95% CI: 1.31, 5.12). DISCUSSION: MCI is a risk factor for dementia and for depressive and anxiety disorders, suggesting common pathological pathways for cognitive and psychiatric outcomes.

The N-terminal pro B-type natriuretic peptide, and risk of dementia and cognitive decline: a 10-year follow-up study in the general population.

BACKGROUND: The N-terminal pro B-type natriuretic peptide (NT-proBNP) has a well-documented prognostic value for cardiovascular disease (CVD) and higher levels are associated with cognitive-dysfunction in patients with CVD. However, how NT-proBNP relates to incident dementia and cognitive-decline in community-dwelling persons is unknown. METHODS: Between 1997 and 2001, serum NT-proBNP was measured in 6040 participants (mean age 69 years, 57% women) free of heart-failure and dementia from the Rotterdam Study. Participants were continuously followed-up for incident dementia until 2012, for 56,616 person-years. Cognition was assessed at baseline and reassessed between 2002 and 2006 by Letter-Digit-Substitution-task, Stroop test and Word-Fluency test. Associations of NT-proBNP with dementia (555 cases), Alzheimer's disease (357 cases) and vascular dementia (32 cases) were assessed linearly, and in quartiles using Cox regression. Associations of NT-proBNP with cognitive-decline were assessed using multiple linear regression. All analyses were repeated after excluding patients with CVD. RESULTS: Higher NT-proBNP was associated with a higher risk of dementia, even after excluding patients with CVD and adjusting for cardiovascular risk factors, HR per SD 1.27 (95% CI 1.13 to 1.44). Associations were particularly strong for vascular dementia, HR per SD 2.04 (95% CI 1.18 to 3.55), but also for Alzheimer's disease when comparing the second and third quartile with first. Higher NT-proBNP was cross-sectionally associated with poorer performance in multiple cognitive tests but longitudinally only in Letter-Digit-Substitution-task. CONCLUSIONS: NT-proBNP reflecting subclinical CVD is associated with dementia, particularly vascular dementia. NT-proBNP can be a useful marker of imminent cognitive-decline and dementia in absence of clinical CVD.

Higher Education Is Associated with a Lower Risk of Dementia after a Stroke or TIA. The Rotterdam Study.

BACKGROUND: Higher education is associated with a lower risk of dementia, possibly because of a higher tolerance to subclinical neurodegenerative pathology. Whether higher education also protects against dementia after clinical stroke or transient ischemic attack (TIA) remains unknown. METHODS: Within the population-based Rotterdam Study, 12,561 participants free of stroke, TIA and dementia were followed for occurrence of stroke, TIA and dementia. Across the levels of education, associations of incident stroke or TIA with subsequent development of dementia and differences in cognitive decline following stroke or TIA were investigated. RESULTS: During 124,862 person-years, 1,463 persons suffered a stroke or TIA, 1,158 persons developed dementia, of whom 186 developed dementia after stroke or TIA. Risk of dementia after a stroke or TIA, compared to no stroke or TIA, was highest in the low education category (hazards ratio [HR] 1.46, 95% CI 1.18-1.81) followed by intermediate education category (HR 1.36, 95% CI 1.03-1.81). No significant association was observed in the high education category (HR 0.62, 95% CI 0.25-1.54). In gender stratified analyses, decrease in risk of dementia with increasing education was significant only in men. CONCLUSION: Higher education is associated with a lower risk of dementia after stroke or TIA, particularly in men, which might be explained by a higher cognitive reserve.

GENOME-WIDE ASSOCIATION STUDY (GWAS) AND GENOME-WIDE BY ENVIRONMENT INTERACTION STUDY (GWEIS) OF DEPRESSIVE SYMPTOMS IN AFRICAN AMERICAN AND HISPANIC/LATINA WOMEN.

BACKGROUND: Genome-wide association studies (GWAS) have made little progress in identifying variants linked to depression. We hypothesized that examining depressive symptoms and considering gene-environment interaction (GxE) might improve efficiency for gene discovery. We therefore conducted a GWAS and genome-wide by environment interaction study (GWEIS) of depressive symptoms. METHODS: Using data from the SHARe cohort of the Women's Health Initiative, comprising African Americans (n = 7,179) and Hispanics/Latinas (n = 3,138), we examined genetic main effects and GxE with stressful life events and social support. We also conducted a heritability analysis using genome-wide complex trait analysis (GCTA). Replication was attempted in four independent cohorts. RESULTS: No SNPs achieved genome-wide significance for main effects in either discovery sample. The top signals in African Americans were rs73531535 (located 20 kb from GPR139, P = 5.75 × 10(-8) ) and rs75407252 (intronic to CACNA2D3, P = 6.99 × 10(-7) ). In Hispanics/Latinas, the top signals were rs2532087 (located 27 kb from CD38, P = 2.44 × 10(-7) ) and rs4542757 (intronic to DCC, P = 7.31 × 10(-7) ). In the GEWIS with stressful life events, one interaction signal was genome-wide significant in African Americans (rs4652467; P = 4.10 × 10(-10) ; located 14 kb from CEP350). This interaction was not observed in a smaller replication cohort. Although heritability estimates for depressive symptoms and stressful life events were each less than 10%, they were strongly genetically correlated (rG = 0.95), suggesting that common variation underlying self-reported depressive symptoms and stressful life event exposure, though modest on their own, were highly overlapping in this sample. CONCLUSIONS: Our results underscore the need for larger samples, more GEWIS, and greater investigation into genetic and environmental determinants of depressive symptoms in minorities.

Subjective memory complaints and the risk of stroke.

BACKGROUND AND PURPOSE: Persons with cognitive impairment, as assessed by cognitive tests, are at a higher risk of stroke. Subjective memory complaints might be an earlier marker for stroke, especially in persons with higher education. Their cognitive reserve might mask their cognitive impairment during cognitive testing. In a population-based setting, we investigated the association between subjective memory complaints and stroke. We simultaneously investigated the association between Mini-Mental State Examination and stroke. We also assessed whether these associations varied with educational level. METHODS: 9152 participants from the Rotterdam Study (baseline 1990-1993 or 2000-2001) completed the subjective memory complaints questionnaire and underwent Mini-Mental State Examination assessment. Subsequently, the entire cohort was followed for incident stroke until 2012. We used Cox proportional hazard models to estimate the associations between subjective memory complaints and Mini-Mental State Examination, with stroke. RESULTS: During a follow-up of 111 593 person years, 1134 strokes were identified, of which 663 were ischemic and 99 hemorrhagic. In the fully adjusted model, presence of subjective memory complaints was independently associated with a higher risk of stroke (hazard ratio, 1.20; 95% confidence interval, 1.04-1.39), but a higher Mini-Mental State Examination was not (hazard ratio per point increase, 0.99; 95% confidence interval, 0.95-1.02). The association between subjective memory complaints and risk of stroke was modified by educational level, with a higher risk of stroke in persons with a higher level of education (hazard ratio, 1.39; 95% confidence interval, 1.07-1.81). CONCLUSIONS: Subjective memory complaints might be an early indicator of stroke risk, especially in highly educated individuals.

Positive affect is not associated with incidence of cardiovascular disease: a population-based study of older persons.

INTRODUCTION: The relationship between positive psychological well-being (PPWB) and cardiovascular disease (CVD) is inconsistent across different CVD outcomes and for different PPWB constructs, such as positive affect. In addition, the relationship between PPWB and CVD as a composite measure is rarely assessed. OBJECTIVE: To assess whether positive affect is protective of incident CVD. METHOD: Positive affect was assessed in two cohorts between 1993 and 2001 in Rotterdam using relevant questions from the Center for Epidemiological Studies Depression (CES-D) scale and the Hospital Anxiety and Depression Scale (HADS; in a sub-sample) in 6349 non-demented, CVD-free, consenting adults, aged 55+years. Composite CVD was defined as stroke, heart failure and coronary heart disease, which were continuously monitored through medical records until 1st April 2010. RESULTS: There were 1480 (23.3%) first time CVD events during follow-up (11.9 ± 2.8 SD years, 58,416 person-years). Positive affect was not associated with incident CVD (CES-D HR: 1.00 per point, 95% CI: 0.98-1.02; HADS HR: 0.98, 95% CI: 0.92-1.05). Stratification by age or sex and assessment of separate CVD outcome did not change results. CONCLUSION: In this large, population-based study, there was no association between positive affect and twelve-year incident CVD in older adults who were free of diagnosed CVD at baseline.

Genetic diversity is a predictor of mortality in humans.

BACKGROUND: It has been well-established, both by population genetics theory and direct observation in many organisms, that increased genetic diversity provides a survival advantage. However, given the limitations of both sample size and genome-wide metrics, this hypothesis has not been comprehensively tested in human populations. Moreover, the presence of numerous segregating small effect alleles that influence traits that directly impact health directly raises the question as to whether global measures of genomic variation are themselves associated with human health and disease. RESULTS: We performed a meta-analysis of 17 cohorts followed prospectively, with a combined sample size of 46,716 individuals, including a total of 15,234 deaths. We find a significant association between increased heterozygosity and survival (P = 0.03). We estimate that within a single population, every standard deviation of heterozygosity an individual has over the mean decreases that person's risk of death by 1.57%. CONCLUSIONS: This effect was consistent between European and African ancestry cohorts, men and women, and major causes of death (cancer and cardiovascular disease), demonstrating the broad positive impact of genomic diversity on human survival.

Anxiety is not associated with the risk of dementia or cognitive decline: the Rotterdam Study.

OBJECTIVE: Anxiety and depression frequently co-occur in the elderly and in patients with dementia. Prior research has shown that depression is related to the risk of dementia, but the effect of anxiety on dementia remains unclear. We studied whether anxiety symptoms and anxiety disorders are associated with the risk of dementia and cognition. METHODS: We studied 2,708 nondemented participants from the prospective, population-based Rotterdam Study who underwent the Hospital Anxiety and Depression Scale (HADS) (sample I, baseline 1993-1995) and 3,069 nondemented participants who underwent screening for anxiety disorders (sample II, baseline 2002-2004). In 1993-1995, anxiety symptoms were assessed using the HADS. In 2002-2004, anxiety disorders were assessed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. In both study samples, participants were continuously monitored for dementia until January 1, 2011. Cognition was tested in 2002-2004 and at a follow-up visit in 2009-2011 in sample II only. RESULTS: In sample I, 358 persons developed dementia, and in sample II, 248 persons developed dementia. We did not find an association with the risk of dementia for anxiety symptoms (hazard ratio 1.05, 95% confidence interval: 0.77-1.43, Wald statistic 0.08, p = 0.77, df = 1) or for anxiety disorders (hazard ratio 0.92, 95% confidence interval: 0.58-1.45, Wald statistic 0.14, p = 0.71, df = 1). We could demonstrate an association of anxiety disorders with poor cognition cross-sectionally, but this attenuated after additional adjustments. CONCLUSION: Our findings do not offer evidence for an association between anxiety symptoms or anxiety disorders with the risk of dementia or with cognition. This suggests that anxiety is not a risk factor nor a prodrome of dementia in an elderly, community-dwelling population.

Coffee consumption and incident dementia.

Coffee consumption has been frequently reported for its protective association with incident dementia. However, this association has mostly been reported in studies with short follow-up periods, and it remains unclear to what extent reverse causality influences this association. Studying the long-term effect of coffee consumption on dementia with stratified follow-up time may help resolve this issue. In the population-based Rotterdam Study, coffee consumption was assessed in 1989-1991 (N = 5,408), and reassessed in 1997-1999 (N = 4,368). Follow-up for dementia was complete until 2011. We investigated the association of coffee consumption and incident dementia for the two examination rounds separately using flexible parametric survival models. We studied the entire follow-up period as well as stratified follow-up time at 4 years. For both examination rounds, we did not find an association between coffee consumption and dementia over the entire follow-up. In contrast, for both examination rounds, a protective association was observed only in the follow-up stratum of 0-4 years. Our data suggest that coffee consumption is not associated with incident dementia during long-term. The protective association observed in the short-term might be driven by reverse causality.

Depressive symptoms predict incident dementia during short- but not long-term follow-up period.

BACKGROUND: Whether depression is a long-term risk factor for dementia or represents a dementia prodrome is unclear. Therefore, we examined the relationship between depressive symptoms and dementia during short and long follow-up in a population-based cohort. METHODS: In the Rotterdam Study, 4393 nondemented individuals were followed for incident dementia for 13.7 years by continuous monitoring. Cox proportional hazards models for different time intervals were used to estimate the risk of incident dementia. RESULTS: Five-hundred eighty-two participants developed dementia during 13.7 years. Persons with depressive symptoms had an 8% increased risk of dementia compared with those without depressive symptoms during the overall follow-up. The risk was highest in the short and intermediate follow-up, particularly in men. We did not find an association in the follow-up period beyond 10 years. CONCLUSION: Our results suggest that late-life depressive symptoms are part of a dementia prodrome rather than an independent risk factor of dementia.

Virtual Compared With In-Person Neurologic Examination Study.

Background and Objectives: The COVID-19 pandemic forced a shift to virtual care in several neurologic care settings. Little is known about the validity of the virtual neurologic examination (VNE) for clinical decision making when compared with the in-person neurologic examination (IPNE). The objective of this study was to investigate the utility of the VNE in arriving at an accurate localization and diagnosis in comparison with the traditional IPNE in an ambulatory outpatient setting. Methods: A retrospective chart review of patients examined virtually and in-person within 4 months at outpatient general neurology and neuromuscular clinics from 2 tertiary academic care centers during the COVID-19 pandemic was conducted. The Cohen kappa coefficient was calculated to test agreement between virtual and in-person assessment results, and descriptive statistical methods were used to compare accuracy, localization, and diagnosis. Results: A total of 81 patients met the inclusion criteria. Overall, there was fair agreement between VNE and IPNE (64% agreement, p = 0.003). Substantial agreement between VNE and IPNE was observed for gait abnormalities; moderate agreement for extraocular movements, facial weakness, dysarthria, fasciculation, and lower limb weakness; and fair agreement for bulk, upper limb weakness, and sensation. No agreement between VNE and IPNE was seen for hypokinetic or hyperkinetic movements and cerebellar signs. Compared with the IPNE, specificity of the VNE was 86% and sensitivity was 56%. Some cases demonstrated a consistent localization (44%) and diagnosis (57%) after virtual and in-person assessments. The localization was changed in 15% and refined in 41% of cases between visits. The diagnosis was changed in 14% and refined in 30% of cases. Discussion: The high rates of agreement in detecting an abnormality on the VNE and IPNE for some maneuvers and resultant clinical impressions may support the validity of the VNE for initial consultation depending on the clinical scenario. The VNE seems to be a good surrogate evaluation compared with the IPNE for certain chief complaints. The low sensitivity suggests that a normal VNE should warrant further in-person clinical correlation, especially in the context of a highly concerning history. The IPNE is more sensitive in detecting subtle abnormalities on examination, and a low threshold should be used to bring a patient in for an IPNE if the VNE is normal in certain clinical contexts.

Effects of white matter hyperintensities, neuropsychiatric symptoms, and cognition on activities of daily living: Differences between Alzheimer's disease and dementia with Lewy bodies.

Introduction: Disability is common across Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). White matter hyperintensities (WMHs) are prevalent in both diagnoses and associated with disability; both diagnoses show neuropsychiatric symptoms (NPS) and impaired cognition. Methods: In AD and DLB, we examined if WMHs, NPS, and cognition associate with basic and/or instrumental activities of daily living (BADLs and/or IADLs) cross-sectionally, and longitudinally over ≈1.4 years. Results: Across both diagnoses, NPS were not only associated with greater disability in performing both BADLs and IADLs, but were also associated with a decline in the ability to perform BADLs in the AD group. In the DLB group only, higher WMH volume was associated with greater disability in performing both BADLs and IADLs, and was associated with a decline in the ability to perform BADL over time. Discussion: Management of NPS and WMHs, particularly in DLB, might help maintain functionality in dementia patients for longer.

Location of residence or social class, which is the stronger determinant associated with cardiovascular risk factors among Pakistani population? A cross sectional study.

INTRODUCTION: The prevalence of cardiovascular disease and associated risk factors are increasing globally, particularly in the developing world. Those in the South Asian region are especially at risk of cardiovascular disease due to an increasing prevalence of its risk factors. This study was undertaken to investigate the association of social class with location of residence in the distribution of cardiovascular risk factors (mainly hypertension and diabetes mellitus) in Pakistan. METHODS: A cross-sectional study of 2495 subjects aged between 30-75 years was conducted in Punjab Province, which includes urban and rural areas. Subjects completed a detailed questionnaire, and anthropometric measurements and blood samples were taken after a written informed consent. Participants were categorized as urban or rural and assigned a social class according to their occupation. A logistic regression model was used to explore the association between social class and location of residence. RESULTS: The overall prevalence of hypertension and diabetes was 24.2% and 16.6%, respectively. Of the total number of participants, 56.8% (n=1417) were rural residents and 43.2% (n=1078) were urban. Urban individuals were significantly more likely (p<0.001) to be hypertensive (OR=3.03, 95% CI 2.14-4.30) and more likely (p<0.001) to be diabetic (OR=1.77, 95% CI 1.29-2.42) than rural dwellers, after multivariate adjustments for age, sex, BMI and social class. Social class was not significantly associated with the prevalence of either hypertension or diabetes. CONCLUSIONS: In the Pakistani population, rural or urban location of residence is a more powerful determinant of cardiovascular risk factors than social class.

Association of low-frequency and rare coding variants with information processing speed.

Measures of information processing speed vary between individuals and decline with age. Studies of aging twins suggest heritability may be as high as 67%. The Illumina HumanExome Bead Chip genotyping array was used to examine the association of rare coding variants with performance on the Digit-Symbol Substitution Test (DSST) in community-dwelling adults participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. DSST scores were available for 30,576 individuals of European ancestry from nine cohorts and for 5758 individuals of African ancestry from four cohorts who were older than 45 years and free of dementia and clinical stroke. Linear regression models adjusted for age and gender were used for analysis of single genetic variants, and the T5, T1, and T01 burden tests that aggregate the number of rare alleles by gene were also applied. Secondary analyses included further adjustment for education. Meta-analyses to combine cohort-specific results were carried out separately for each ancestry group. Variants in RNF19A reached the threshold for statistical significance (p = 2.01 × 10-6) using the T01 test in individuals of European descent. RNF19A belongs to the class of E3 ubiquitin ligases that confer substrate specificity when proteins are ubiquitinated and targeted for degradation through the 26S proteasome. Variants in SLC22A7 and OR51A7 were suggestively associated with DSST scores after adjustment for education for African-American participants and in the European cohorts, respectively. Further functional characterization of its substrates will be required to confirm the role of RNF19A in cognitive function.