Lutsey, Pamela L.

AbstractBackgroundAlthough amyloid deposition in the brain is often associated with subsequent dementia risk, not everyone with brain amyloid will develop dementia. This discrepancy illustrates the potential importance that risk factors and lived experiences may have in modifying this association. Compared to participants with low social engagement (SE) in mid‐life, we hypothesized that participants with high mid‐life SE will show a weaker association between amyloid burden and incident dementia.MethodWe included data from 310 non‐demented participants of the Atherosclerosis Risk in Communities (ARIC)‐PET study. Social support and isolation were assessed via interviewer‐administered questionnaires (Visit 2; 1990 – 1992). Based upon categorization of both factors, participants were classified as having high, intermediate, or low mid‐life SE (Table 1). Brain amyloid was evaluated with florbetapir PET (Visit 5; 2011‐2014). Elevated amyloid burden was defined as standardized uptake value ratio (SUVR) >1.2 in the global cortex. Incident dementia cases were identified from visit 5 through 2019 through ongoing surveillance utilizing in‐person neurocognitive testing, informant interviews, and hospitalization codes. Relative contributions of mid‐life SE and elevated florbetapir SUVR to incident dementia, independently and with multiplicative interaction terms, were evaluated with Cox regression models, adjusted for demographics, APOEε4 and vascular risk factorsResultAmong 310 participants, 48 developed dementia (median follow‐up: 4.7 years). Mid‐life SE and elevated SUVR each independently predicted dementia risk but did not interact on a multiplicative scale. Participants with high or intermediate mid‐life SE, relative to low mid‐life SE, were less likely to develop dementia (Table 2). Although the interaction between mid‐life SE and elevated SUVR was not significant, stratified models suggested a stronger association between amyloid burden and dementia in participants with high mid‐life SE (Table 3).ConclusionGreater mid‐life SE was associated with lower odds of developing dementia, independent of elevated SUVR. Although protective, there was no strong evidence for effect modification of mid‐life SE on the association between amyloid and dementia risk. Future longitudinal studies evaluating the potential influence of social factors measured throughout the life course are needed to inform our understanding as to what factors may preserve cognition in the presence of elevated brain pathology.

AbstractBackgroundAlthough amyloid deposition in the brain is often associated with subsequent dementia risk, not everyone with brain amyloid will develop dementia. This discrepancy illustrates the potential importance that risk factors and lived experiences may have in modifying this association. Compared to participants with low social engagement (SE) in mid‐life, we hypothesized that participants with high mid‐life SE will show a weaker association between amyloid burden and incident dementia.MethodWe included data from 310 non‐demented participants of the Atherosclerosis Risk in Communities (ARIC)‐PET study. Social support and isolation were assessed via interviewer‐administered questionnaires (Visit 2; 1990 – 1992). Based upon categorization of both factors, participants were classified as having high, intermediate, or low mid‐life SE (Table 1). Brain amyloid was evaluated with florbetapir PET (Visit 5; 2011‐2014). Elevated amyloid burden was defined as standardized uptake value ratio (SUVR) >1.2 in the global cortex. Incident dementia cases were identified from visit 5 through 2019 through ongoing surveillance utilizing in‐person neurocognitive testing, informant interviews, and hospitalization codes. Relative contributions of mid‐life SE and elevated florbetapir SUVR to incident dementia, independently and with multiplicative interaction terms, were evaluated with Cox regression models, adjusted for demographics, APOEe4 and vascular risk factorsResultAmong 310 participants, 48 developed dementia (median follow‐up: 4.7 years). Mid‐life SE and elevated SUVR each independently predicted dementia risk but did not interact on a multiplicative scale. Participants with high or intermediate mid‐life SE, relative to low mid‐life SE, were less likely to develop dementia (Table 2). Although the interaction between mid‐life SE and elevated SUVR was not significant, stratified models suggested a stronger association between amyloid burden and dementia in participants with high mid‐life SE (Table 3).ConclusionGreater mid‐life SE was associated with lower odds of developing dementia, independent of elevated SUVR. Although protective, there was no strong evidence for effect modification of mid‐life SE on the association between amyloid and dementia risk. Future longitudinal studies evaluating the potential influence of social factors measured throughout the life course are needed to inform our understanding as to what factors may preserve cognition in the presence of elevated brain pathology.

Background: Lower (worse) left atrial (LA) function is associated with higher dementia risk. It is unclear whether lower LA function is associated with vascular brain injury on brain MRI, an established correlate for higher dementia risk. Using data from the Atherosclerosis Risk in Communities (ARIC) study, we assessed the cross-sectional association between LA function measures and brain MRI markers of vascular brain injury (cerebral microbleeds, brain infarcts). Hypothesis: Participants with lower LA function will be more likely to have presence of > 1 cerebral microbleed or brain infarct. Methods: ARIC participants who had both an echocardiogram and brain MRI at visit 5 (2011-13) were included. We excluded those with prevalent dementia, stroke, or atrial fibrillation. LA function measures were obtained from 2D-echocardiograms and assessed in quartiles (highest quartile was the reference). Brain MRI measures were assessed as the presence or absence of > 1 cerebral microbleed or brain infarct. Logistic regression was used. Results: Of the 1502 participants (mean [SD] age 76 [5], 60% female, 27% Black) in this analysis, 345 (23%) and 351 (23%) had > 1 cerebral microbleed or brain infarct present. Compared to the highest quartile, lower LA reservoir and conduit strain quartiles were associated with higher odds of cerebral microbleeds. LA contractile strain was not associated with cerebral microbleeds. Compared to the highest quartile, the lowest LA conduit strain quartile, but not reservoir strain, was associated with higher odds of brain infarcts. LA contractile strain was inversely associated with brain infarcts. Conclusion: In this community-based cohort, lower LA function was cross-sectionally associated with cerebral microbleeds and brain infarcts. The inverse relationship with LA contractile strain may be due to contractile function compensating for a decrease in early diastolic filling. Prospective studies are needed to confirm these findings.

Background: Cardiovascular health may be used for prevention of cerebral vascular disease; however, data on the association of cardiovascular health across midlife and late-life with late-life cerebral vascular disease are lacking. Our aim was to examine whether midlife or late-life cardiovascular health as well as changes of cardiovascular health within midlife and between midlife and late-life were associated with prevalence of magnetic resonance imaging markers of cerebral vascular disease at late-life. Methods: Prospective cohort study including 1638 participants from the Atherosclerosis Risk in Communities Study who took part in 2 visits at midlife (mean ages, 53 and 59 years), and a late-life visit (mean age, 76 years). A cardiovascular health Life’s Simple 7 score (range, 0–12/0–14, depending on diet availability) including 6 out of 7 items was calculated at each visit, with weight assigned to each item as poor (0), intermediate (1), or ideal (2). Participants underwent 3T brain magnetic resonance imaging scans in late-life visit. Outcomes were white matter hyperintensity volume, microbleeds, and lacunar, subcortical, and cortical infarcts at late-life. Linear and logistic regression models were used to assess the associations of cardiovascular health in midlife and late-life, and improvement of cardiovascular health within midlife, and from midlife to late-life with magnetic resonance imaging markers of cerebral vascular disease, adjusting for potential confounders. Results: A higher cardiovascular health in midlife, improvement of cardiovascular health within midlife, higher cardiovascular health at late-life, and improvement of cardiovascular health from midlife to late-life were associated with a lower prevalence of cerebral vascular disease markers. For example, improvement in cardiovascular health (per point) from midlife to late-life was associated with smaller white matter hyperintensity volume (β, −0.07 [95% CI, −0.10 to −0.04]) and lower odds of microbleeds (odds ratio, 0.93 [0.90–0.97]), lacunar (odds ratio, 0.93 [0.89–0.97]), subcortical (odds ratio, 0.93 [0.89–0.97]), and cortical infarcts (odds ratio, 0.92 [0.87–0.97]). Conclusions: Improving cardiovascular health within midlife and from midlife to late-life may prevent development of cerebral vascular disease.

AbstractBackgroundRecent evidence indicates that abnormal P‐wave parameters (PWPs)—ECG markers of atrial myopathy—are associated with incident dementia, independent of atrial fibrillation (AF) and clinical ischemic stroke. However, the mechanisms remain unclear and may include subclinical vascular brain injury. Hence, we evaluated the association of abnormal PWPs with brain MRI correlates of vascular brain injury in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC‐NCS).MethodsARIC‐NCS participants who underwent 3T brain MRI scans in 2011–2013 were included. PWPs were measured from standard 12‐lead ECGs. Brain MRI outcomes included cortical infarcts, lacunar infarcts, cerebral microhemorrhages, brain volumes, and white matter disease (WMD) volume. We used weighted multivariable logistic and linear regression to evaluate the associations of abnormal PWPs with brain MRI outcomes.ResultsAmong 1715 participants (mean age, 76.1 years; 61% women; 29% Black), 797 (46%) had ≥1 abnormal PWP. After multivariable adjustment, including adjusting for prevalent AF, abnormal P‐wave terminal force in lead V1 (aPTFV1) and prolonged P‐wave duration (PPWD) were associated with increased odds of both cortical (OR 1.41; 95% CI, 1.14 to 1.74 and OR 1.30; 95% CI, 1.04 to 1.63, respectively) and lacunar infarcts (OR 1.36; 95% CI, 1.15 to 1.63 and OR 1.37; 95% CI, 1.15 to 1.65, respectively). Advanced interatrial block (aIAB) was associated with higher odds of subcortical microhemorrhage (OR 2.04; 95% CI, 1.36 to 3.06). Other than a significant association between aPTFV1 with lower parietal lobe volume, there were no other significant associations with brain or WMD volume.ConclusionIn this exploratory analysis of a US community‐based cohort, ECG surrogates of atrial myopathy are associated with a higher prevalence of brain infarcts and microhemorrhage, suggesting subclinical vascular brain injury as a possible mechanism underlying the association of atrial myopathy with dementia.

Introduction: Hypertension in midlife, but not late life, is a robust predictor of subsequent dementia. However, the fraction of dementia attributable to hypertension might vary depending on the age of the population considered, and the age through which dementia onset occurs. Here, we investigated associations of hypertension assessed at various ages with incident dementia by age 80 or 90, then estimated population attributable fractions (PAF) for dementia from hypertension categories at each of these age groups. Hypothesis: Given hypertension prevalence increases with age but its relative risk for dementia tends to decrease, we had no prior expectation of the age at which the PAF’s would be highest. We hypothesized, however, that PAFs for incident dementia would be higher when hypertension is measured in midlife age groups versus late-life age groups. Methods: We leveraged 32 years of follow-up data from the Atherosclerosis Risk in Communities study (ARIC), a prospective, community-based cohort that enrolled participants aged 45-64 years from four US communities (Washington County, MD; Forsyth County, NC; Jackson, MS; and selected suburbs of Minneapolis, MI) at ARIC visit 1 (1987-1989). Participants were followed through 2018-2019. We used Cox proportional hazards models to estimate hazard ratios, then quantified PAFs, of dementia by age 80 and 90 from hypertension assessed at ages of 45-54 (ARIC visit 1), 55-64 (ARIC visits 1 and 4), 65-74 (ARIC visits 4 and 5), and 75-84 (ARIC visit 5). Results: Hypertension was assessed among 7,572 participants aged 45-54; 12,033 aged 55-64; and 6,561 aged 65-74. By age 80 the number identified as having incident dementia was 711, 910, and 372, respectively. Relative to normotension, hypertension in each age category was associated with hazard ratios (HRs) greater than 1.0 for dementia from hypertension by age 80. The PAF for dementia by age 80 from hypertension measured at age 45-54 was 15.3% (95% CI = 6.9, 22.3%), 19.1% (95% CI = 9.9, 26.9%) at ages 55-64, and 19.9% (95% CI = -4.4, 38.5%) at ages 65-74. By age 90, the number of incident dementia cases were 958; 2,302; and 1,327, respectively; and, among the 2,086 participants aged 75-84, 400 incident dementia cases. HRs were slightly smaller than those by age 80, while hypertension assessed in the 75-84 age group was not significant. The PAFs for dementia by age 90 from hypertension at age 45-54 was 13.8% (95% CI = 6.6, 20.0%), 12.9% (95% CI = 7.0, 18.2%) at ages 55-64, 10.9% (95% CI = 0.02, 21.0%) at ages 65-74, and non-significant at ages 75-84. Conclusions: Public health interventions targeting hypertension in midlife through early late-life might reduce a sizeable proportion of dementia cases.

AbstractINTRODUCTIONThe fraction of dementia attributable to hypertension might vary depending on the age of the population considered and the age through which dementia occurs.METHODSIn the Atherosclerosis Risk in Communities study, we quantified population attributable fractions (PAF) of dementia by age 80 and 90 from hypertension assessed at ages of 45–54 (n = 7572), 55–64 (n = 12,033), 65–74 (n = 6561), and 75–84 (n = 2086).RESULTSThe PAF for dementia by age 80 from all non‐normal blood pressure at ages 45–54 was 15.3% (95% confidence interval [CI] = 6.9%–22.3%), 19.1% (95% CI = 9.9%–26.9%) at ages 55–64, and 19.9% (95% CI = −4.4%–38.5%) at ages 65–74. The strongest PAFs were from stage 2 hypertension (11.9%–21.3%). For dementia by age 90, PAFs from non‐normal blood pressure up through age 75 were smaller (10.9%–13.8%), and non‐significant by age 75–84.DISCUSSIONInterventions targeting hypertension even in early late life might reduce a sizeable proportion of dementia.Highlights We estimated prospective population attributable risks of dementia for hypertension. 15%–20% of dementia cases by age 80 are from non‐normal blood pressure (BP). Associations between hypertension and dementia persisted through age 75. Midlife to early late‐life BP control might reduce a large proportion of dementia.

Introduction: Cardiovascular health may be used for prevention of cerebral vascular disease. We evaluated whether improvement of cardiovascular health within midlife and from midlife to late-life were each associated with lower prevalence of MRI markers of cerebral vascular disease at late-life. Methods: 1,638 participants from the Atherosclerosis Risk in Communities (ARIC) Study took part in two visits at midlife (mean ages 53 at ARIC visit 1 and 59 at visit 3), and a late-life visit (mean age 76). A cardiovascular health Life’s Simple 7 score (range 0-12/0-14, depending on diet availability) including six/seven items was calculated at each visit, with weight assigned to each item as poor (0), intermediate (1), or ideal (2). Participants underwent 3T brain MRI scans in 2011-2013 (late-life visit). Outcomes were white matter hyperintensity volume, microbleeds, and lacunar, subcortical, and cortical infarcts at late-life. Linear and logistic regression models were used to assess the associations of cardiovascular health with MRI markers of cerebral vascular disease. Results: Thirty nine percent of participants had high cardiovascular health at midlife visit 1, 32% at midlife visit 3, and 33% at late-life. Improvement of cardiovascular health within midlife and from midlife to late-life were each associated with a lower prevalence of cerebral vascular disease markers. For example, improvement in cardiovascular health (per point) from midlife to late-life was associated with smaller white matter hyperintensity volume (Beta:-0.07 [95%CI:-0.10,-0.04]), and lower odds of microbleeds (OR:0.93 [0.90,0.97]), lacunar (OR:0.93 [0.89,0.97)], subcortical (OR:0.93 [0.89,0.97])], and cortical infarcts (OR:0.92 [0.87,0.97)] (Figure). Conclusions: Improving cardiovascular health within midlife and from midlife to late-life may prevent development of cerebral vascular disease.

AbstractIntroductionWe evaluated whether better cardiovascular health at midlife and improvement of cardiovascular health within midlife were associated with dementia risk.MethodsTwo longitudinal population‐based studies were used: Atherosclerosis Risk in Communities (ARIC) (n = 11,460/visits at ages 54 and 60), and Age, Gene/Environment Susceptibility (AGES)‐Reykjavik (n = 3907/visit at age 51). A cardiovascular health score (range 0–12/0–14, depending on diet availability) including six/seven items was calculated at each visit, with weight assigned to each item as poor (0), intermediate (1), or ideal (2). Cardiovascular health was defined as low (score 0–4/0–5), intermediate (5–7/6–9), or high (8–12/10–14). Incident dementia was ascertained through linkage to health records and with neuropsychological examinations.ResultsMidlife high compared to low cardiovascular health (hazard ratios [HRs]: for ARIC: 0.60 [95% confidence interval: 0.52, 0.69]); for AGES‐Reykjavik: 0.83 [0.66, 0.99] and improvement of cardiovascular health score within midlife (HR per one‐point increase: ARIC: 0.94 [0.92, 0.96]) were associated with lower dementia risk.DiscussionBetter cardiovascular health at midlife and improvement of cardiovascular health within midlife are associated with lower dementia risk.Highlights Cardiovascular health and dementia were studied in two large cohort studies. Better cardiovascular health at midlife relates to lower dementia risk. Improvement of cardiovascular health within midlife relates to lower dementia risk. Promotion of cardiovascular health at midlife can help to reduce dementia risk.

Background: Venous thromboembolism (VTE) is a life-threatening vascular event with environmental and genetic determinants. Recent VTE genome-wide association studies (GWAS) meta-analyses involved nearly 30 000 VTE cases and identified up to 40 genetic loci associated with VTE risk, including loci not previously suspected to play a role in hemostasis. The aim of our research was to expand discovery of new genetic loci associated with VTE by using cross-ancestry genomic resources. Methods: We present new cross-ancestry meta-analyzed GWAS results involving up to 81 669 VTE cases from 30 studies, with replication of novel loci in independent populations and loci characterization through in silico genomic interrogations. Results: In our genetic discovery effort that included 55 330 participants with VTE (47 822 European, 6320 African, and 1188 Hispanic ancestry), we identified 48 novel associations, of which 34 were replicated after correction for multiple testing. In our combined discovery-replication analysis (81 669 VTE participants) and ancestry-stratified meta-analyses (European, African, and Hispanic), we identified another 44 novel associations, which are new candidate VTE-associated loci requiring replication. In total, across all GWAS meta-analyses, we identified 135 independent genomic loci significantly associated with VTE risk. A genetic risk score of the significantly associated loci in Europeans identified a 6-fold increase in risk for those in the top 1% of scores compared with those with average scores. We also identified 31 novel transcript associations in transcriptome-wide association studies and 8 novel candidate genes with protein quantitative-trait locus Mendelian randomization analyses. In silico interrogations of hemostasis and hematology traits and a large phenome-wide association analysis of the 135 GWAS loci provided insights to biological pathways contributing to VTE, with some loci contributing to VTE through well-characterized coagulation pathways and others providing new data on the role of hematology traits, particularly platelet function. Many of the replicated loci are outside of known or currently hypothesized pathways to thrombosis. Conclusions: Our cross-ancestry GWAS meta-analyses identified new loci associated with VTE. These findings highlight new pathways to thrombosis and provide novel molecules that may be useful in the development of improved antithrombosis treatments.