BACKGROUND: The progression of FLAIR white matter hyperintensities (WMHs) on MRI heralds vascular-mediated cognitive decline. Even before FLAIR WMH progression, adjacent normal appearing white matter (NAWM) already demonstrates microstructural deterioration on diffusion tensor imaging (DTI). We hypothesized that elevated DTI free water (FW) would precede FLAIR WMH progression, implicating interstitial fluid accumulation as a key pathological step in the progression of cerebral small vessel disease. METHODS: Participants at least 3 months after an ischemic stroke or TIA with WMH on MRI underwent serial brain MRIs every 3 months over the subsequent year. For each participant, the WMHs were automatically segmented, serial MRIs were aligned, and a region of WMH penumbra tissue at risk was defined by dilating lesions at any time point and subtracting baseline lesions. Penumbra voxels were classified as either stable or progressing to WMH if they were segmented as new lesions and demonstrated increasing FLAIR intensity over time. Aligned DTI images included FW and FW-corrected fractional anisotropy (FATissue) and mean diffusivity (MDTissue). Logistic regression and area under the receiver-operator characteristic curve (AUC) were used to test whether baseline DTI predicted voxel-wise classification of stable penumbra or progression to WMH while covarying for clinical risk factors. RESULTS: In the included participants (n = 26, mean age 71 ± 9 years, 31% female), we detected a median annual voxel-wise WMH growth of 2.9 ± 2.6 ml. Each baseline DTI metric was associated with lesion progression in the penumbra, but FW had the greatest AUC of 0.732 (0.730 - 0.733) for predicting voxel-wise WMH progression pooled across participants. DISCUSSION: Baseline increased interstitial fluid, estimated as FW on DTI, predicted the progression of NAWM to WMH over the following year. These results implicate the presence of FW in the pathogenesis of cerebral small vessel disease progression.

BACKGROUND AND OBJECTIVES: Studies on the association between proton pump inhibitor (PPI) use and dementia report mixed results and do not examine the impact of cumulative PPI use. We evaluated the associations between current and cumulative PPI use and risk of incident dementia in the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: These analyses used participants from a community-based cohort (ARIC) from the time of enrollment (1987-1989) through 2017. PPI use was assessed through visual medication inventory at clinic visits 1 (1987-1989) to 5 (2011-2013) and reported annually in study phone calls (2006-2011). This study uses ARIC visit 5 as baseline because this was the first visit in which PPI use was common. PPI use was examined 2 ways: current use at visit 5 and duration of use before visit 5 (from visit 1 to 2011, exposure categories: 0 day, 1 day-2.8 years, 2.8-4.4 years, >4.4 years). The outcome was incident dementia after visit 5. Cox proportional hazard models were used, adjusted for demographics, comorbid conditions, and other medication use. RESULTS: A total of 5,712 dementia-free participants at visit 5 (mean age 75.4 ± 5.1 years; 22% Black race; 58% female) were included in our analysis. The median follow-up was 5.5 years. The minimum cumulative PPI use was 112 days, and the maximum use was 20.3 years. There were 585 cases of incident dementia identified during follow-up. Participants using PPIs at visit 5 were not at a significantly higher risk of developing dementia during subsequent follow-up than those not using PPIs (hazard ratio (HR): 1.1 [95% confidence interval (CI) 0.9-1.3]). Those who used PPIs for >4.4 cumulative years before visit 5 were at 33% higher risk of developing dementia during follow-up (HR: 1.3 [95% CI 1.0-1.8]) than those reporting no use. Associations were not significant for lesser durations of PPI use. DISCUSSION: Future studies are needed to understand possible pathways between cumulative PPI use and the development of dementia. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that the use of prescribed PPIs for >4.4 years by individuals aged 45 years and older is associated with a higher incidence of newly diagnosed dementia.

Objective

Examine whether cognitive reserve moderates the association of 1) vascular risk factors and 2) white matter hyperintensity burden with risk of clinical progression and longitudinal cognitive decline.

Methods

BIOCARD Study participants were cognitively normal and primarily middle-aged (M = 57 years) at baseline and have been followed with annual cognitive and clinical assessments (M = 13 years). Baseline cognitive reserve was indexed with a composite score combining education with reading and vocabulary scores. Baseline vascular risk (N = 229) was assessed with a composite risk score reflecting five vascular risk factors. Baseline white matter hyperintensity load (N = 271) was measured with FLAIR magnetic resonance imaging. Cox regression models assessed risk of progression from normal cognition to onset of clinical symptoms of Mild Cognitive Impairment. Longitudinal mixed effects models measured the relationship of these variables to cognitive decline, using a global composite score, and executive function and episodic memory sub-scores.

Results

Both vascular risk and white matter hyperintensities were associated with cognitive decline, particularly in executive function. Higher vascular risk, but not white matter hyperintensity burden, was associated with an increased risk of progression to Mild Cognitive Impairment. Higher cognitive reserve was associated with a reduced risk of symptom onset and higher levels of baseline cognition but did not modify the associations between the vascular risk score and white matter hyperintensities with clinical progression or cognitive decline.

Interpretation

Although cognitive reserve has protective effects on clinical and cognitive outcomes, it does not mitigate the negative impact of vascular risk and small vessel cerebrovascular disease on these same outcomes.

Objective

We aimed to assess the association between migraine headache and incident dementia.

Background

Migraine is a risk factor for white matter hyperintensities and ischemic stroke, which are both associated with increased risk of dementia. However, it is unknown whether migraine is independently associated with dementia.

Methods

History of migraine was ascertained via questionnaire. Adjudicated cases of dementia were identified using cognitive tests, neuropsychological exams, and clinician review of suspected cases. Incident dementia was identified using adjudicated cases, follow-up calls, and surveillance of hospital and death codes. We assessed hazards of incident dementia by migraine status. Sex differences were also examined and stratified results were presented.

Results

Analysis included 12,495 White and African American participants ages 51-70 with a median follow-up time of 21 years. Prevalence of dementia was 18.5% (1821/9955) among those with no migraine history, 15.8% (196/1243) among those with severe non-migraine heading, and 16.7% (233/1397) among migraineurs. There was no association between migraine and incident dementia [hazard ratio: 1.04 (0.91, 1.20)]. There was also no statistically significant interaction between sex and migraine status on risk of dementia.

Conclusion

Despite evidence of brain abnormalities in migraineurs, there was no association between migraine and incident dementia in this prospective cohort.

Background

Depression is a common neuropsychiatric consequence of stroke, but there is little empiric evidence regarding clinical diagnosis and management of poststroke depression.

Methods

Retrospective cohort study among 831 471 privately insured patients with first stroke in the USA from 2003 to 2020. We identified diagnoses of poststroke depression using codes from the International Classification of Diseases. We identified treatment based on prescriptions for antidepressants. We used Cox proportional hazards regression analysis to examine rates of poststroke depression diagnosis by gender, age and race/ethnicity. Among individuals who received a diagnosis of poststroke depression, we estimated treatment rates by gender, race/ethnicity and age using negative binomial regression analysis.

Results

Annual diagnosis and treatment rates for poststroke depression increased from 2003 to 2020 (both p for trend<0.001). Diagnosis rates were higher in women than men (HR 1.53, 95% CI 1.51 to 1.55), lower among members of racial/ethnic minorities (vs white patients: Asian HR 0.63, 95% CI 0.60 to 0.66; Black HR 0.76, 95% CI 0.74 to 0.78; Hispanic HR 0.88, 95% CI 0.86 to 0.90) and varied by age. Among individuals diagnosed with poststroke depression, 69.8% were prescribed an antidepressant. Rates of treatment were higher in women vs men (rate ratio, RR=1.19, 95% CI: 1.17 to 1.21), lower among members of racial/ethnic minorities (vs white patients: Asian RR 0.85, 95% CI 0.80 to 0.90; Black RR 0.92, 95% CI 0.89 to 0.94; Hispanic RR 0.96, 95% CI 0.93 to 0.99) and higher among older patients.

Conclusions

In this insured population, we identify potential inequities in clinical management of poststroke depression by gender, race/ethnicity and age that may reflect barriers other than access to healthcare.

Objective

Recent studies suggest that white matter hyperintensities (WMH) on MRI, which primarily reflect small vessel cerebrovascular disease, may play a role in the evolution of Alzheimer disease (AD). In a longitudinal study, we investigated whether WMH promote the progression of AD pathology, or alter the association between AD pathology and risk of progression from normal cognition to mild cognitive impairment (MCI).

Methods

Two sets of analyses were conducted. The relationship between whole brain WMH load, based on fluid-attenuated inversion recovery MRI, obtained in initially cognitively normal participants (n = 274) and time to onset of symptoms of MCI (n = 60) was examined using Cox regression models. In a subset of the participants with both MRI and CSF data (n = 204), the interaction of WMH load and CSF AD biomarkers was also evaluated.

Results

Baseline WMH load interacted with CSF total tau (t-tau) with respect to symptom onset, but not with CSF β-amyloid 1-42 or phosphorylated tau (p-tau) 181. WMH volume was associated with time to symptom onset of MCI among individuals with low t-tau (hazard ratio [HR] 1.35, confidence interval [CI] 1.06-1.73, p = 0.013), but not those with high t-tau (HR 0.86, CI 0.56-1.32, p = 0.47). The rate of change in the CSF biomarkers over time was not associated with the rate of change in WMH volumes.

Conclusion

These results suggest that WMH primarily affect the risk of progression when CSF measures of neurodegeneration or neuronal injury (as reflected by t-tau) are low. However, CSF biomarkers of amyloid and p-tau and WMH appear to have largely independent and nonsynergistic effects on the risk of progression to MCI.

Background Increased carotid intima-media thickness, interadventitial diameter, presence of carotid plaque, and lower distensibility are predictors for cardiovascular disease. These indices likely relate to cerebrovascular disease, and thus may constitute a form of vascular contributions to dementia and Alzheimer disease-related dementia. Therefore, we assessed the relationship of carotid measurements and arterial stiffness with incident dementia in the ARIC (Atherosclerosis Risk in Communities) study. Methods and Results A total of 12 459 ARIC participants with carotid arterial ultrasounds in 1990 to 1992 were followed through 2017 for dementia. Dementia cases were identified using in-person and phone cognitive status assessments, hospitalization discharge codes, and death certificate codes. Cox proportional hazards models were used to estimate the hazard ratios (HRs) for incident dementia. Participants were aged 57±6 at baseline, 57% were women, and 23% were Black individuals. Over a median follow-up time of 24 years, 2224 dementia events were ascertained. After multivariable adjustments, the highest quintile of carotid intima-media thickness and interadventitial diameter in midlife was associated with increased risk of dementia (HR [95% CIs], 1.25 [1.08-1.45]; and 1.22 [1.04-1.43], respectively) compared with its respective lowest quintile. Presence of carotid plaque did not have a significant association with dementia (HR [95% CI], 1.06 [0.97-1.15]). Higher distensibility was associated with lower risk of dementia (HR [95% CI] highest versus lowest quintile, 0.76 [0.63-0.91]). Conclusions Greater carotid intima-media thickness, interadventitial diameter, and lower carotid distensibility are associated with an increased risk of incident dementia. These findings suggest that both atherosclerosis and carotid stiffness may be implicated in dementia risk.

Presence of coronary artery calcium (CAC), carotid plaque, and increased carotid intima-media thickness (IMT) may indicate elevated cardiovascular disease (CVD) risk; however, no large studies have compared them directly. This study compares predictive uses of CAC presence, carotid artery plaque presence, and high IMT for incident CVD events. Participants were from the Multi-Ethnic Study of Atherosclerosis (MESA). Predictive values of carotid plaque, IMT, and CAC presence were compared using Cox proportional hazards models, c-statistics, and net reclassification indices. The 6779 participants were mean (SD) 62.2 (10.2) years old; 49.9% had CAC, and 46.7% had carotid plaque. The mean left and right IMT were 0.754 (0.210) mm and 0.751 (0.187) mm, respectively. After 9.5 years (mean), 538 CVD events, 388 coronary heart disease (CHD) events, and 196 stroke/transient ischemic attacks were observed. CAC presence was a stronger predictor of incident CVD and CHD than carotid ultrasound measures. Mean IMT≥75th percentile (for age, sex, and race) alone did not predict events. Compared with traditional risk factors, c-statistics for CVD (c=0.756) and CHD (c=0.752) increased the most by the addition of CAC presence (CVD, 0.776; CHD, 0.784; P<0.001) followed by carotid plaque presence (CVD, c=0.760; CHD, c=0.757; P<0.05). Compared with risk factors (c=0.782), carotid plaque presence (c=0.787; P=0.045) but not CAC (c=0.785; P=0.438) improved prediction of stroke/transient ischemic attacks. In adults without CVD, CAC presence improves prediction of CVD and CHD more than carotid plaque presence or high IMT. CAC and carotid ultrasound parameters performed similarly for stroke/transient ischemic attack event prediction.

Strategies to prevent or delay Alzheimers disease and related dementias (AD/ADRD) are urgently needed, and blood pressure (BP) management is a promising strategy. Yet the effects of different BP control strategies across the life course on AD/ADRD are unknown. Randomized trials may be infeasible due to prolonged follow-up and large sample sizes. Simulation analysis is a practical approach to estimating these effects using the best available existing data. However, existing simulation frameworks cannot estimate the effects of BP control on both dementia and cardiovascular disease. This manuscript describes the design principles, implementation details, and population-level validation of a novel population-health microsimulation framework, the MIchigan ChROnic Disease SIMulation (MICROSIM), for The Effect of Lower Blood Pressure over the Life Course on Late-life Cognition in Blacks, Hispanics, and Whites (BP-COG) study of the effect of BP levels over the life course on dementia and cardiovascular disease. MICROSIM is an agent-based Monte Carlo simulation designed using computer programming best practices. MICROSIM estimates annual vascular risk factor levels and transition probabilities in all-cause dementia, stroke, myocardial infarction, and mortality in a nationally representative sample of US adults 18+ using the National Health and Nutrition Examination Survey (NHANES). MICROSIM models changes in risk factors over time, cognition and dementia using changes from a pooled dataset of individual participant data from 6 US prospective cardiovascular cohort studies. Cardiovascular risks were estimated using a widely used risk model and BP treatment effects were derived from meta-analyses of randomized trials. MICROSIM is an extensible, open-source framework designed to estimate the population-level impact of different BP management strategies and reproduces US population-level estimates of BP and other vascular risk factors levels, their change over time, and incident all-cause dementia, stroke, myocardial infarction, and mortality.

Background

Coronary artery calcium (CAC) predicts atherosclerotic cardiovascular disease (ASCVD) events, inclusive of coronary heart disease (CHD) and stroke, and is a decision-making aid for primary prevention. The predictive value of CAC categories for CHD and stroke separately and across sex and race groups of an asymptomatic population is unclear.

Methods

White, Black, and Hispanic participants of MESA (Multi-Ethnic Study of Atherosclerosis) and DHS (Dallas Heart Study) underwent CAC measurement at enrollment and were followed for incident ASCVD events. Ten-year CHD-to-stroke incidence ratios across CAC score categories 0, 1 to 99, and ≥100 were assessed. Associations of CAC with incident CHD and stroke events were evaluated using multivariable-adjusted Cox models and multiplicative interactions of CAC with sex/race were tested.

Results

Among 7042 participants (mean age, 57 years, 54% women, 36% Black, 23% Hispanic, 49% CAC=0, 19% CAC ≥100), 574 incident ASCVD events (333 CHD and 241 stroke) were observed over 12.3-year follow-up. Ten-year CHD-to-stroke incidence ratio increased significantly across CAC categories in men, women, Whites, Blacks, and Hispanics (all P<0.001). High CAC burden (score ≥100) was independently associated with ASCVD and CHD risk in all groups and with stroke risk in the overall cohort and Blacks. No sex- or race-based CAC interactions for ASCVD, CHD, and stroke events were observed. Adding CAC to a traditional risk factor model improved risk discrimination and reclassification for CHD but not for stroke events.

Conclusions

In 2 population-based cohorts of asymptomatic individuals, 10-year CHD-to-stroke incidence ratio was higher with increasing CAC score categories across sex and race groups, and CAC was consistently a better predictor of CHD than stroke. High CAC burden comparably associated with ASCVD risk across sex and race groups.