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Background: Prior studies have reported a link between traumatic brain injury (TBI) and risk of adverse neuropsychiatric outcomes including dementia. However it is unclear how prevalent these conditions are prior to TBI and if they are predisposing factors in addition to sequalae. Methods: We studied older (age >55 years) US veterans who were followed for care at Veterans Affairs Medical Centers across the nation from 2000 to 2019. We first identified all veterans with an incident TBI diagnoses defined as no prior TBI diagnosis, having been seen in an emergency department (ED), having a brain imaging scan (primarily CT) within one day of ED visit and with a subsequent new TBI diagnosis in the electronic medical record (EMR). We then determined 2‐year age‐adjusted prevalence rates (rate per 1000 person‐years and 95% confidence interval or CI) for dementia and mild cognitive impairment (MCI) prior to and post incident TBI. We also compared prior TBI prevalence to prevalence among 1:3 matched (on age and index date) veterans without TBI. Results: There were 13,709 primarily male veterans with incident TBI with mean age of 77.7 sd 9.1 years, 81% were non‐Hispanic White. Compared to the 41,127 veterans without TBI (mean age = 77.9, sd 9.1), veterans prior to having an incident TBI had almost a six‐fold greater pre‐TBI age‐adjusted prevalence of dementia (104.9; 95% CI 100.8‐109.0 vs 18.6; 95% CI 17.6‐19.7, p<0.001) and MCI (48.0; 95% CI 45.2‐50.7 vs 8.1; 95% CI 7.4‐8.8, p<0.001). After the incident TBI diagnosis, the age‐adjusted prevalence rates were even higher: dementia (193.5; 95% CI 187.7‐199.2) and MCI (59.3; 95% CI 56.0‐62.6). Conclusions: Among older US veterans, there is a bidirectional association with dementia/ MCI and TBI with very high prevalence prior to TBI (compared to those without TBI) and even greater prevalence after TBI. These findings highlight the importance of prevention strategies for both pre‐ and post‐TBI cognitive impairment. [ABSTRACT FROM AUTHOR]

Background: Residence in a disadvantaged neighborhood is associated with adverse health exposures and outcomes, and may increase risk for cognitive impairment and dementia. We investigated the association of the area deprivation index (ADI) with dementia in in a sample of the national Veteran population. Methods: We examined data from the Veterans Health Administration (VHA), the largest integrated health care system in the United States. We studied 1,613,337 patients who obtained VHA care from 10/1/1999 to 9/30/2021, (n = 1,395,872 White; n = 147,530 Black) aged ≥55 years (mean: 68.6, SD: 7.7), 98% male. We characterized neighborhood deprivation with the ADI, a validated measure that combines 17 specific indicators (e.g., income, education, employment and housing) into an index of disadvantage. Participant zip codes from residential addresses were geocoded and assigned an ADI national rank according to their census block group. We used these data to categorize participants into ADI rank quintiles, where higher ADI rank quintile corresponds with more deprivation. We estimated adjusted incidence rates of dementia (International Classification of Diseases, 9th and 10th Edition codes) using Cox proportional hazards regression with age as the time scale. Results: During a mean follow‐up of up to 11 (SD 4.8) years, 208,909 participants (12.8%) developed dementia. Compared to the least disadvantaged neighborhood quintile, all other groups had an increased risk of developing dementia in models adjusted for sex, race/ ethnicity, and psychiatric and medical comorbidities. The association was dose‐dependent, with the most disadvantaged quintile demonstrating the greatest risk (Quintile 2 HR: 1.09 95% CI: 1.07, 1.11; Quintile 3 HR: 1.14, 95% CI: 1.12, 1.16; Quintile 4 HR: 1.17, 95% CI: 1.16, 1.19, Quintile 5 HR: 1.24, 95% CI: 1.22, 1.26, Quintile 1 reference group). Repeating our main analysis using competing risks regression led to similar results. Conclusion: We found a dose‐dependent association between ADI and dementia The ADI may be a valuable tool for identifying high‐risk communities for dementia intervention. [ABSTRACT FROM AUTHOR]

Background: Although the US military is increasingly diverse, the association of race/ethnicity and geographical region with incidence of dementia diagnosis among older Veterans is unknown. Method: We identified a random sample of 1,869,090 patients age ≥ 55 years [mean age: 69.4 (standard deviation 7.9), 2% female] who received care at the Veterans Health Administration (VHA), the largest integrated health care system in the United States, between October 1, 1999 and September 30, 2019. Participants self‐reported race/ethnicity: White: 88.6% (n = 1,655,376); Black, 9.5% (n = 176,795); Hispanic (1.0%, n = 20,663), Asian (0.5%, n = 9,391), or American Indian/Alaska Native [AIAN (0.4%, n = 6,895). US region was derived using residential ZIP codes and categorized based on 10 Center for Disease Control and Prevention Health Promotion regions. Incident dementia was defined using International Classification of Diseases, 9th (ICD‐9) and 10th (ICD‐10) edition codes; age‐adjusted dementia incidence was estimated using direct standardization to compare rates by race/ethnicity overall and by US region. Result: Over a mean follow‐up of 10.1 years, 243,272 (13%) participants received a diagnosis of dementia. Age‐adjusted incidence per 1,000 person‐years was 14.2 [95% confidence interval (CI), 13.3‐15.1] for AIAN participants, 12.4 (95% CI, 11.7‐13.1) for Asian participants, 19.4 (95% CI, 19.2‐19.6) for Black participants, 20.7 (95% CI, 20.1‐21.3) for Hispanic participants, and 11.5 (95% CI, 11.4‐11.6) for White participants. Across US regions, a similar pattern was observed; compared to White participants, rates were significantly higher for Black participants across all regions (15.5 to 20.7, p values <0.001), and for Hispanic participants in all regions except the Southeast (14.0 to 21.7, p values ≤ 0.03). Across most regions, AIAN (8.6 to 16.2,) and Asian participants (8.4 to 15.6,) showed a pattern of rates that was similar to or slightly higher than for White participants (9.8 to 12.0, p values >0.05). Conclusion: Among older Veterans receiving care at VHA, where access to care for enrollees is held relatively equal, differences in dementia incidence were observed based on race/ethnicity. Across US regions, rates varied, but incidence was consistently higher for Black and Hispanic Veterans. Further research is needed to elucidate drivers of these differences. [ABSTRACT FROM AUTHOR]

Background: People living with HIV (PLWH) may be at increased risk for dementia because of increased major risk factors, chronic infection (and inflammation), and long‐term use of highly active antiretroviral therapy (HAART). Our goal was to determine whether HIV‐infection is associated with incident dementia diagnosis in older U.S. veterans accounting for important potential confounders and competing risk of death. Methods: We included 1114 veterans, ages ≥ 55 years (mean age=62 years, SD 6), with HIV in the Veterans Health Administration health care system from 2004 to 2015, and a propensity‐matched comparison group (n= 1114) without HIV. HIV and dementia diagnoses were determined using International Classification of Diseases, Ninth Revision codes and Diagnostic Related Group codes in electronic medical records. We conducted Fine‐Gray proportional hazards models to determine whether HIV status was associated with greater risk of incident dementia and adjusting for demographics and co‐morbidities. Result: During follow‐up (mean=7 years, SD 4 from date of HIV diagnosis) 5% of veterans living with HIV developed dementia compared to 3% without (p=0.01). Accounting for the competing risk of death, in a model adjusted only for demographics, veterans with HIV had a 60% increased risk of dementia compared to those without HIV (adjusted hazard ratio 1.59, 95% confidence interval, CI, 1.04 ‐2.43.) In a model adjusted for age, sex, race, substance use, education and income PLWH were still 50% more likely to receive a dementia diagnosis (aHR 1.50, 95% CI 0.96‐2.35). Conclusion: In a cohort of older US veterans, we found that HIV infection increases risk of developing dementia. As the population of PLWH in the US ages, understanding general and unique dementia risk factors for this group is key to developing appropriate prevention and mitigation strategies. [ABSTRACT FROM AUTHOR]

Background: Although the U.S. military is increasingly diverse, the impact of sex and race on incidence of dementia diagnosis among older Veterans is unknown. Method: We compared incidence of dementia diagnosis among self‐reported race groups (Non‐Hispanic White, Non‐Hispanic Black, Hispanic, and Asian) and by sex among a random sample of all Veterans > 65 years in the Veterans Health Administration between 10/1/2003 and 9/30/2015. We included Veterans without baseline prevalent dementia (over a 2‐year baseline) with >1 visit during the follow‐up period (< 12 years). Dementia was defined as inpatient/ outpatient diagnoses using International Classification of Disease 9th Edition (ICD‐9) codes recommended by the VA Dementia Steering Committee, dementia medication prescription, or both. We calculated crude incidence by age, sex, and race; and conducted Cox models adjusted for age and sex/race. We further adjusted models for education, income, cardiac/metabolic, and military (post‐traumatic stress disorder, traumatic brain injury) risk factors. Result: The analytic cohort included 497,127 Veterans (mean age 75.4) after excluding 18,314 with baseline dementia and 11,058 without follow‐up. About eight percent (n=40,352) were diagnosed with dementia during follow‐up. Overall incidence increased by age (50/1000 people, ages 65‐74; 112/1000 for 75‐84, and 116/1000 among 85+; p<0.001). Across all ages, males' incidence (81/1000) was similar to females' (77/1000; p=0.10); adjusted Hazard ratio (HR) for females vs. males: 0.96, 95% Confidence Interval (CI) 0.89‐1.03. Hispanic Veterans had highest incidence (154/1000), while Asian veterans had lowest (71/1000); incidence for white Veterans was 79/1000, and 101/1000 for Black Veterans. Compared to white Veterans, Asian Veterans had borderline lower risk of dementia diagnosis (HR: 0.87, 95% CI 0.76‐1.01), and Black (HR: 1.61, 95% CI 1.55‐1.66) and Hispanic Veterans (HR: 1.80, 1.68‐1.93) had increased risk. The pattern of results was similar after full adjustment (Hispanic HR 1.59, 95% CI 1.48‐ 1.71; Black HR 1.49, 95% CI 1.44‐1.54; Asian HR 0.89, 95% CI 0.77‐1.04). Conclusion: Among older U.S. Veterans, there were differences in incidence of dementia diagnosis by race: Black and Hispanic Veterans had almost two‐fold greater risk compared to white Veterans. Asian Veterans had lower risk. Females and males had similar incidence. These results highlight health disparities requiring further study. [ABSTRACT FROM AUTHOR]

Background: A growing body of evidence suggests that social support is associated with cognitive outcomes including dementia in late‐life. Yet few studies have examined the association between social support and cognition in mid‐life, a critical time of transition to aging. Furthermore, little is known about the effects of other aspects of social function such as emotional support, social strain and loneliness on cognition. Our goal was to investigate the association between several social support factors and cognitive performance in mid‐life. Method: We studied 2,732 Black and White adults from the Coronary Artery Risk Development in Young Adults (CARDIA) Study who completed a social support questionnaire at baseline (CARDIA Year 20, mean age 45.2 years, 57% female, 45% Black) which assessed aspects of emotional support, social strain, and loneliness. At the 10‐year follow‐up, cognitive performance was evaluated with a battery of five tests: Digit Symbol Substitution Test (DSST), Rey Auditory Verbal Learning Test (RAVLT), Stroop Test, Verbal Fluency (category and letter fluency), and the Montreal Cognitive Assessment (MOCA) and standardized to z‐scores. We used linear regression to determine the association between emotional support, social strain, and loneliness, categorized as tertiles (comparing high to low), with mid‐life cognition. Result: In unadjusted models, all three social support factors were associated with cognition 10 years later. After adjusting for age, sex, race, education, marital status, income, and depression, participants reporting higher levels of emotional support performed better on all cognitive tests (DSST High vs. Low (z‐score)=0.13 [95%CI 0.03, 0.23]; RAVLT=0.17 [95%CI 0.07, 0.27]; reverse Stroop=0.15 [95%CI 0.05, 0.26]; Verbal Fluency=0.12 [95%CI 0.01, 0.23]; MOCA=0.19 [95%CI 0.09, 0.28]). Less social strain was associated with higher scores on most tests (DSST Low vs. High=0.16 [95%CI 0.06, 0.26]; RAVLT=0.11 [95%CI 0.01, 0.21]; and MOCA=0.13 [95%CI 0.04, 0.23]). Loneliness was not associated with mid‐life cognition. Conclusion: Greater level of social support, particularly emotional support, was associated with better mid‐life cognitive outcomes 10 years later. To better inform risk and prevention efforts, more research should be conducted to investigate the associations between various dimensions of social support and cognitive outcomes across the life course. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular risk factors are associated with worse cognition, yet less is known about the impact of cardiac structure and function and their adverse effects on the brain possibly from decreased perfusion. The few studies included older patients with cardiovascular disease and relied on single echocardiographic assessment. Method: We included 2256 subjects from the CARDIA (Coronary Artery Risk Development in Young Adults) study (60% women, 44% black). Echocardiograms were repeated at Years 5, 25, 30 (mean age 30, 50, 55 years, respectively) to assess cardiac structure: left ventricular mass (LVMi), left atrial volume (LAVi) and systolic function: left ventricular ejection fraction (LVEF). Diastolic function was assessed at Year 25 as the ratio of early peak mitral velocity (E)/early peak mitral annular velocity (e'). Five cognitive domains were assessed at Year 30: verbal memory [Rey Auditory Verbal Learning Test (RAVLT)], category and letter fluency, processing speed [Digit Symbol Substitution Test (DSST)], executive function [Stroop] and global cognition [Montreal Cognitive Assessment MoCA]. We investigated the association of (1) 25‐year change and (2) Year 25 cardiac structure and function on midlife cognition using linear regressions. Result: Over 25 years, LVMi and LAVi increased with mean change (SD) of 5.7 g/m² (21.7) and 9.6 mL/m² (7.4) while LVEF decreased by mean (SD) change of 1.5% (9.0). After adjustment for demographics and education, abnormal cardiac structure assessed by greater 25‐year increase (≥ 1‐SD) in LVMi was associated with lower cognition on most tests: RAVLT (6.2 vs. 6.8, p<0.001), DSST (59.7 vs. 61.7, p=0.02), Stroop (29.0 vs. 27.2, p=0.01) and MoCA (19.1 vs 19.7, p=0.001). Similarly, greater 25‐year increase in LAVi was associated with lower MoCA (19.8 vs. 20.3, p=0.04). Further adjustment for hypertension, diabetes and smoking reported similar findings. 25‐year decrease in LVEF was not associated with cognition. In addition, higher Year 25 LVMi, LAVi and E/e' ratio were significantly associated with worse cognition on most cognitive tests. Conclusion: Midlife cardiac structure and its change from early to middle adulthood are associated with lower midlife cognition. Moreover, midlife diastolic but not systolic function is linked to cognition. Our results provide novel information linking cardiac structure and function to cognition. [ABSTRACT FROM AUTHOR]