Sleep duration and brain MRI measures: Results from the SOL-INCA MRI study.

INTRODUCTION: Sleep duration has been associated with dementia and stroke. Few studies have evaluated sleep pattern-related outcomes of brain disease in diverse Hispanics/Latinos. METHODS: The SOL-INCA (Study of Latinos-Investigation of Neurocognitive Aging) magnetic resonance imaging (MRI) study recruited diverse Hispanics/Latinos (35-85 years) who underwent neuroimaging. The main exposure was self-reported sleep duration. Our main outcomes were total and regional brain volumes. RESULTS: The final analytic sample included n = 2334 participants. Increased sleep was associated with smaller brain volume (ßtotal_brain  = -0.05, p < 0.01) and consistently so in the 50+ subpopulation even after adjusting for mild cognitive impairment status. Sleeping >9 hours was associated with smaller gray (ßcombined_gray  = -0.17, p < 0.05) and occipital matter volumes (ßoccipital_gray  = -0.18, p < 0.05). DISCUSSION: We found that longer sleep duration was associated with lower total brain and gray matter volume among diverse Hispanics/Latinos across sex and background. These results reinforce the importance of sleep on brain aging in this understudied population. HIGHLIGHTS: Longer sleep was linked to smaller total brain and gray matter volumes. Longer sleep duration was linked to larger white matter hyperintensities (WMHs) and smaller hippocampal volume in an obstructive sleep apnea (OSA) risk group. These associations were consistent across sex and Hispanic/Latino heritage groups.

Connections between reproductive health and cognitive aging among women enrolled in the HCHS/SOL and SOL-INCA.

INTRODUCTION: Reproductive health history may contribute to cognitive aging and risk for Alzheimer's disease, but this is understudied among Hispanic/Latina women. METHODS: Participants included 2126 Hispanic/Latina postmenopausal women (44 to 75 years) from the Study of Latinos-Investigation of Neurocognitive Aging. Survey linear regressions separately modeled the associations between reproductive health measures (age at menarche, history of oral contraceptive use, number of pregnancies, number of live births, age at menopause, female hormone use at Visit 1, and reproductive span) with cognitive outcomes at Visit 2 (performance, 7-year change, and mild cognitive impairment [MCI] prevalence). RESULTS: Younger age at menarche, oral contraceptive use, lower pregnancies, lower live births, and older age at menopause were associated with better cognitive performance. Older age at menarche was protective against cognitive change. Hormone use was linked to lower MCI prevalence. DISCUSSION: Several aspects of reproductive health appear to impact cognitive aging among Hispanic/Latina women.

To donate, or not to donate, that is the question: Latino insights into brain donation.

INTRODUCTION: Latinos are underrepresented in brain autopsy research on Alzheimer's disease and related dementias (ADRD). The study's purpose is to identify Latinos' attitudes about brain donation (BD) to inform methods by which researchers can increase autopsy consent. METHODS: Forty Latinos (mean age: 59.4 years) completed a semi-structured interview and were presented with educational information about BD. Participants completed a questionnaire assessing their understanding of BD and willingness to donate their brain for research. RESULTS: Among participants, there was near unanimous support for BD to study ADRD after hearing educational information. However, prior to the information presented, participants reported a lack of knowledge about BD and demonstrated a possibility that misunderstandings about BD may affect participation. DISCUSSION: While nearly all study participants agree that donating is beneficial for research and for future generations, the lack of BD information must be addressed to help support positive attitudes and willingness for participation.

Risk factors associated with occupational noise-induced hearing loss in the Hispanic community health study/study of Latinos: A cross-sectional epidemiologic investigation.

The purpose of this study was to estimate the prevalence of occupational noise exposure and risk factors of occupational noise-induced hearing loss (NIHL) in Hispanic/Latino adults included in the baseline wave of the Hispanic Community Health Study/Study of Latinos collected from 2008 to 2011. Sequential multiple linear regression modeled the relationship between occupational NIHL (defined as a 3-, 4-, 6-kHz pure-tone average [PTA]) and occupation type, self-reported noise exposure, cardiovascular disease (CVD) risk score, and hearing protective device (HPD) use. The final model controlled for sex, age, and recreational noise exposure. Among 12,851 included participants, approximately 40% (n = 5036) reported occupational noise exposure "Sometimes" (up to 50% of the time) or "Frequently" (75-100% of the time). In the final fitted model, longest-held occupation and CVD risk were associated with poorer hearing. Specifically, those in non-skilled, service, skilled, and military/police/other job categories had between 2.07- and 3.29-dB worse PTA than professional/office workers. Additionally, a shift in the CVD risk score category from low to medium was associated with a 2.25- and 8.20-dB worse PTA for medium and high CVD risk, respectively. Age and sex were also significantly associated with poorer hearing, such that men presented with 6.08 dB worse PTA than women, and for every one-year increase in age, PTA increased by 0.62 dB (ps < .001). No interactions were seen between noise*sometimes or frequent exposure to other ototoxic agents and PTA (ps = .33 & .92, respectively). The prevalence of occupational noise exposure was high in this cross-sectional investigation of adults from Hispanic/Latino backgrounds. Findings contribute to the extant literature by demonstrating that risk factors for occupational NIHL in adults from varying Hispanic/Latino backgrounds are consistent with those of other previously studied groups.

Cardiovascular risk factors and APOE-ε4 status affect memory functioning in aging via changes to temporal stem diffusion.

Prior research investigating associations between hypertension, obesity, and apolipoprotein (APOE) genotype status with memory performance among older adults has yielded inconsistent results. This may reflect, in part, a lack of first accounting for the effects these variables have on structural brain changes, that in turn contribute to age-related memory impairment. The current study sought to clarify the relationships between these factors via path modeling. We hypothesized that higher body mass index (BMI), hypertension, and being an APOE-ε4 allele carrier would predict poorer memory scores, with much of these effects accounted for by indirect effects operating via differences in the integrity of temporal stem white matter. Participants included 125 healthy older adults who underwent neuropsychological assessment and diffusion-weighted MRI scanning. Direct effects were found for hypertension and demographic variables including age, sex, and education. Importantly, indirect effects were found for BMI, hypertension, APOE-ε4 status, age, and sex, where these factors predicted memory scores via their impact on temporal stem diffusion measures. There was also a dual effect of sex, with a direct effect indicating that females had better memory performance overall, and an indirect effect indicating that females with greater temporal stem diffusion had poorer memory performance. Results suggest that changes to the integrity of temporal white matter in aging may underpin reduced memory performance. These results highlight that accounting for variables that not only directly impact cognition, but also for those that indirectly impact cognition via structural brain changes, is crucial for understanding the impact of risk factors on cognition.

APOE alleles' association with cognitive function differs across Hispanic/Latino groups and genetic ancestry in the study of Latinos-investigation of neurocognitive aging (HCHS/SOL).

INTRODUCTION: Apolipoprotein E (APOE) alleles are associated with cognitive decline, mild cognitive impairment (MCI), and Alzheimer's disease in Whites, but have weaker and inconsistent effects reported in Latinos. We hypothesized that this heterogeneity is due to ancestry-specific genetic effects. METHODS: We investigated the associations of the APOE alleles with significant cognitive decline and MCI in 4183 Latinos, stratified by six Latino backgrounds, and explored whether the proportion of continental genetic ancestry (European, African, and Amerindian) modifies these associations. RESULTS: APOE ε4 was associated with an increased risk of significant cognitive decline (odds ratio [OR] = 1.15, P-value = 0.03), with the strongest association in Cubans (OR = 1.46, P-value = 0.007). APOE-ε2 was associated with decreased risk of MCI (OR = 0.37, P-value = 0.04) in Puerto Ricans. Amerindian genetic ancestry was found to protect from the risk conferred by APOE ε4 on significant cognitive decline. DISCUSSION: Results suggest that APOE alleles' effects on cognitive outcomes differ across six Latino backgrounds and are modified by continental genetic ancestry.

The impact of cardiovascular risk factors on cognition in Hispanics and non-Hispanic whites.

Among non-Hispanic whites, cardiovascular risk factors are associated with increased mortality and poorer cognition. Prevalence of cardiovascular risk factors among aging Hispanics is also high and Hispanics generally have poorer access to healthcare, yet they tend to have advantageous cardiovascular disease rates and outcomes and live longer than non-Hispanic whites, an epidemiological phenomenon commonly referred to as the Hispanic or Latino health paradox. Although robust data support these ethnic benefits on physical health and mortality, it is unknown if it extends to include cognition resilience advantages in older adulthood. The present study compared relationships between cardiovascular risk and cognition (executive functions and episodic memory) in late middle age and older Hispanics (n = 87) and non-Hispanic whites (n = 81). Participants were selected from the National Alzheimer's Coordinating Center and Alzheimer's Disease Neuroimaging Initiative databases. Hispanics and non-Hispanic white groups were matched on age (50-94 yr, mean age = 72 yr), education, gender, cognitive status (i.e., cognitively healthy versus mildly cognitively impaired), and apolipoprotein E4 status. History of hypertension and higher body mass index were both associated with poorer executive functions among Hispanics but not non-Hispanic whites. Our findings suggest greater vulnerability to impairments in executive functions among Hispanics with hypertension and obesity, contrary to the notion of a Hispanic health paradox for cognitive aging.

Glycemic Control, Cognitive Aging, and Impairment Among Diverse Hispanic/Latino Individuals: Study of Latinos- Investigation of Neurocognitive Aging (Hispanic Community Health Study/Study of Latinos).

OBJECTIVE: Hispanic/Latino individuals in the U.S. have the highest prevalence of undiagnosed and untreated diabetes and are at increased risk for cognitive impairment. In this study, we examine glycemic control in relation to cognitive aging and impairment in a large prospective cohort of middle-aged and older Hispanic/Latino individuals of diverse heritages. RESEARCH DESIGN AND METHODS: Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) is a Hispanic Community Health Study/Study of Latinos (HCHS/SOL) ancillary study. HCHS/SOL is a multisite (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA), probability sampled prospective cohort study. SOL-INCA enrolled 6,377 diverse Hispanic/Latino individuals aged 50 years and older (2016-2018). The primary outcomes were cognitive function, 7-year cognitive decline, and mild cognitive impairment (MCI). The primary glycemia exposure variables were measured from fasting blood samples collected at HCHS/SOL visit 1 (2008-2011). RESULTS: Visit 1 mean age was 56.5 years ± 8.2 SD, and the average glycosylated hemoglobin A1C (HbA1c) was 6.12% (43.5 ± 14.6 mmol/mol). After covariate adjustment, higher HbA1c was associated with accelerated 7-year global (b = -0.045; 95% CI -0.070; -0.021; in z score units) and executive cognitive decline and a higher prevalence of MCI (odds ratio 1.20; 95% CI 1.11; 1.29). CONCLUSIONS: Elevated HbA1c levels were associated with 7-year executive cognitive decline and increased MCI risk among diverse middle-aged and older Hispanic/Latino individuals. Our findings indicate that poor glycemic control in midlife may pose significant risks for cognitive decline and MCI later in life among Hispanic/Latino individuals of diverse heritages.

Hypertension, Cognitive Decline, and Mild Cognitive Impairment Among Diverse Hispanics/Latinos: Study of Latinos-Investigation of Neurocognitive Aging Results (SOL-INCA).

BACKGROUND: Hypertension can have deleterious effects on cognitive function; however, few studies have examined its effects on cognition among Hispanics/Latinos. OBJECTIVE: To assess associations between hypertension status with 1) change in cognitive performance, and 2) having mild cognitive impairment (MCI) among diverse Hispanics/Latinos. METHODS: This population-based, prospective cohort, multisite study included Hispanic/Latino adults aged 45 to 72 years in enrolled in the Hispanic Community Health Study/Study of Latinos at Visit 1 (2008-2011; mean age of 63.40±8.24 years), and the Study of Latinos-Investigation of Neurocognitive Aging at Visit 2 (2016-2018), with a mean follow-up duration of 7 years (n = 6,173). Hypertension status was assessed at both visits: normotension (no hypertension), incident hypertension (only at Visit 2), and persistent hypertension (at both visits). We examined change in cognitive performance and having MCI (only assessed at Visit 2) relative to hypertension status and adjusted for demographics and cardiovascular disease risk factors. RESULTS: Compared to normotension, persistent hypertension was associated with significantly increased decline in verbal fluency (ß= -0.08; CI = [-0.16;-0.01]; p < 0.05), and processing speed (ß= -0.11; CI = [-0.20;-0.02]; p < 0.05). Incident hypertension was not associated with significant change in cognitive performance. Both incident (OR = 1.70; CI = [1.16;2.50]; p < 0.01) and persistent hypertension (OR = 2.13; CI = [1.57;2.88]; p < 0.001) were associated with significantly higher odds ratios of having MCI. CONCLUSIONS: These findings indicate that persistent hypertension is associated with clinical impairment and domain-specific cognitive decline in middle-aged and older Hispanics/Latinos. It underscores the importance of monitoring blood pressure in routine healthcare visits beginning at midlife in this population to reduce the burden of cognitive decline.

Associations Between Self-Reported Visual and Hearing Functioning and Cognitive Function Among Hispanics/Latino: Hispanic Community Health Study.

Background and Objectives: To investigate the associations between self-reported visual functioning (VF) and hearing functioning with cognition in the Hispanic/Latino population. Research Design and Methods: We utilized data from the Miami Ocular Study of Latinos ancillary study to Hispanic Community Health Study/Study of Latinos with 1,056 participants aged 45 and older. The outcomes were cognitive performances assessed by the Digit Symbol Substitution Test (DSST), Word Fluency, Brief-Spanish English Verbal Learning Test-recall (B-SEVLT recall), words recalled over 3 trials, and the Six-Item Screener. VF was measured by National Eye Institute Visual Function Questionnaire (NEI-VFQ), and hearing function was measured by Hearing Handicap Inventory Screening Questionnaire for Adults and Elderly (HHIA/E-S). Multiple regressions were performed for each cognitive outcome while controlling for covariates and complex sampling design. Results: NEI-VFQ was associated with 3 of the 5 cognitive outcomes. A 4-point NEI-VFQ score difference was associated with a 0.56-point difference in DSST (standard error [SE] = 0.27, p < .001), 0.17 in Word fluency (SE = 0.16, p < .01), and 0.08 in B-SEVLT-recall (SE = 0.07, p < .01). HHIA/E-S was not associated with any of the cognitive measures examined. Discussion and Implications: These data suggest that impaired VF is associated with worse cognition in the Hispanic/Latino population. Although previous work in this cohort indicated hearing loss assessed by pure tone audiometry was associated with worse cognition, we found self-perceived hearing function was not associated with cognition, suggesting the potential limitation of self-reported hearing function as a proxy for hearing loss in epidemiological research in Hispanic/Latino populations. Results also imply impaired VF and hearing function may be linked to cognition differently in the Hispanic population, and more research is needed to better understand the underlying linking mechanisms. Visual and hearing impairments are common and treatable and represent important modifiable risk factors that can be treated to preserve cognitive function in Hispanics/Latinos.

Hearing Loss and Associated 7-Year Cognitive Outcomes Among Hispanic and Latino Adults.

Importance: Hearing loss appears to have adverse effects on cognition and increases risk for cognitive impairment. These associations have not been thoroughly investigated in the Hispanic and Latino population, which faces hearing health disparities. Objective: To examine associations between hearing loss with 7-year cognitive change and mild cognitive impairment (MCI) prevalence among a diverse cohort of Hispanic/Latino adults. Design, Setting, and Participants: This cohort study used data from a large community health survey of Hispanic Latino adults in 4 major US cities. Eligible participants were aged 50 years or older at their second visit to study field centers. Cognitive data were collected at visit 1 and visit 2, an average of 7 years later. Data were last analyzed between September 2023 and January 2024. Exposure: Hearing loss at visit 1 was defined as a pure-tone average (500, 1000, 2000, and 4000 Hz) greater than 25 dB hearing loss in the better ear. Main outcomes and measures: Cognitive data were collected at visit 1 and visit 2, an average of 7 years later and included measures of episodic learning and memory (the Brief-Spanish English Verbal Learning Test Sum of Trials and Delayed Recall), verbal fluency (word fluency-phonemic fluency), executive functioning (Trails Making Test-Trail B), and processing speed (Digit-Symbol Substitution, Trails Making Test-Trail A). MCI at visit 2 was defined using the National Institute on Aging-Alzheimer Association criteria. Results: A total of 6113 Hispanic Latino adults were included (mean [SD] age, 56.4 [8.1] years; 3919 women [64.1%]). Hearing loss at visit 1 was associated with worse cognitive performance at 7-year follow-up (global cognition: ß = -0.11 [95% CI, -0.18 to -0.05]), equivalent to 4.6 years of aging and greater adverse change (slowing) in processing speed (ß = -0.12 [95% CI, -0.23 to -0.003]) equivalent to 5.4 years of cognitive change due to aging. There were no associations with MCI. Conclusions and relevance: The findings of this cohort study suggest that hearing loss decreases cognitive performance and increases rate of adverse change in processing speed. These findings underscore the need to prevent, assess, and treat hearing loss in the Hispanic and Latino community.

Normative data for the Digit Symbol Substitution for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA).

INTRODUCTION: Executive functioning and processing speed are crucial elements of neuropsychological assessment. To meet the needs of the Hispanic/Latino population, we aimed to provide normative data for the Digit Symbol Substitution (DSS) test. METHODS: The target population for the Study of Latinos-Investigation of Neurocognitive Aging included six heritage backgrounds (n = 6177). Average age was 63.4 ± 8.3 years, 54.5% were female, and mean education was 11.0 ± 4.7 years. Participants were administered the DSS as part of a larger battery. Heritage-adjusted DSS scores, and percentile cut-points were created using survey-adjusted regression and quantile regression models. RESULTS: Age, education, sex, heritage, and language preference were associated with DSS scores. DISCUSSION: Significant correlates of DSS performance should be considered when evaluating cognitive performance. Representative DSS norms for Hispanics/Latinos will advance assessment and accuracy of neurocognitive disorder diagnosis in clinical practice. To facilitate interpretation, we provide norms to reduce test biases and developed an online dashboard. Highlights: Normative data for the Digit Symbol Substitution (DSS) for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) This study is the first to develop norms for the DSS test across four regions of the United States.Factors such as age, education, sex, and Hispanic/Latino heritage and language preference are associated with differences in executive functioning and information processing speed.We created norms and an online dashboard (https://solincalab.shinyapps.io/dsst_shiny/) providing an easily accessible tool to evaluate processing speed and executive functioning in Hispanic/Latino adults.

Association Between Hypertensive Disorders of Pregnancy and Interval Neurocognitive Decline: An Analysis of the Hispanic Community Health Study/Study of Latinos.

OBJECTIVE: To evaluate whether hypertensive disorders of pregnancy, including gestational hypertension, preeclampsia, and eclampsia, are associated with cognitive decline later in life among U.S. Hispanic/Latina individuals. METHODS: The HCHS/SOL (Hispanic Community Health Study/Study of Latinos) is a prospective population-based study of Hispanic/Latino individuals aged 18-74 years from four U.S. communities. This analysis included parous individuals aged 45 years or older who participated in the HCHS/SOL clinic study visit 1 (2008-2011) neurocognitive assessment and subsequently completed a repeat neurocognitive assessment as part of the Study of Latinos-Investigation of Neurocognitive Aging ancillary study visit 2 (2015-2018). Hypertensive disorders of pregnancy were assessed retrospectively by self-report of any gestational hypertension, preeclampsia, or eclampsia. Cognitive functioning was measured at both study visits with the Brief Spanish-English Verbal Learning Test, Digit Symbol Substitution, and Word Fluency. A regression-based approach was used to define cognitive decline at visit 2 as a function of cognition at visit 1 after adjustment for age, education, and follow-up time. Linear regression models were used to determine whether hypertensive disorders of pregnancy or their component diagnoses were associated with standardized cognitive decline after adjustment for sociodemographic characteristics, clinical and behavioral risk factors, and follow-up time. RESULTS: Among 3,554 individuals included in analysis, the mean age was 56.2 years, and 467 of individuals (13.4%) reported at least one hypertensive disorder of pregnancy. Individuals with hypertensive disorders of pregnancy compared with those without were more likely to have higher mean systolic blood pressure, fasting glucose, and body mass index. After an average of 7 years of follow-up, in fully adjusted models, gestational hypertension was associated with a 0.17-SD relative decline in Digit Symbol Substitution scores (95% CI, -0.31 to -0.04) but not other cognitive domains (Brief Spanish-English Verbal Learning Test or Word Fluency). Neither preeclampsia nor eclampsia was associated with neurocognitive differences. CONCLUSION: The presence of preeclampsia or eclampsia was not associated with interval neurocognitive decline. In this cohort of U.S. Hispanic/Latina individuals, gestational hypertension alone was associated with decreased processing speed and executive functioning later in life.

Sleep Apnea and Hypertension Control among Hispanic/Latino Adults in the United States: Results from the Hispanic Community Health Study / Study of Latinos (HCHS/SOL).

Objectives: Hispanic/Latino adults have a high prevalence of uncontrolled hypertension predisposing them to CVD. We hypothesize that sleep apnea severity is associated with uncontrolled blood pressure (BP) and resistant hypertension in Hispanic/Latino adults. Methods: This was a cross-sectional study of 2,849 Hispanic Community Health Study/Study of Latinos participants with hypertension (i.e., systolic BP ≥130 mm Hg, or diastolic BP ≥80 mm Hg or self-reported antihypertensive medication use) who were taking at least one class of antihypertensive medication. Participants were categorized as having controlled (BP < 130/80 mmHg among those on hypertension treatment) , uncontrolled (BP ≥ 130/80 mmHg using one or two classes of antihypertensive medications), or resistant hypertension (BP ≥ 130/80 mmHg while on ≥ 3 classes of antihypertensive medications or the use of ≥ 4 classes of antihypertensive medications regardless of BP control). Sleep apnea was classified based on the respiratory event index (REI; events/h) as mild (REI ≥ 5 and < 15), moderate-to-severe (REI ≥ 15), or no sleep apnea (REI < 5). Results: In multinomial logistic regression, moderate-to-severe sleep apnea (vs. no sleep apnea) was associated with higher odds of resistant hypertension (Odds Ratio [OR], 2.15; 95% CI, 1.36-3.39 at 4% desaturation and OR 1.68; 95% CI, 1.05-2.67 at 3% desaturation). Neither mild nor moderate-to-severe sleep apnea was associated with uncontrolled hypertension. Conclusion: Among diverse Hispanic/Latino persons, moderate-to-severe but not mild sleep apnea was associated with resistant hypertension. Identification and management of sleep apnea in this population may improve BP control and subsequently prevent adverse cardiovascular outcomes.

Associations of Allostatic Load with Level of and Change in Cognitive Function Among Middle-Aged and Older Hispanic/Latino Adults: The Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA).

Background: Higher allostatic load (AL), a multi-system measure of physiological dysregulation considered a proxy for chronic stress exposure, is associated with poorer global cognition (GC) in older non-Hispanic white adults. However, evidence of these associations in middle-aged and older US-based Hispanic/Latino adults is limited. Objective: To examine associations of AL with level of cognition, performance in cognition 7 years later, and change in cognition over 7 years among middle-aged and older US-based Hispanic/Latino adults. Methods: We used data (n = 5,799, 45-74 years at baseline) from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) and SOL-Investigation of Neurocognitive Aging (SOL-INCA). The AL score comprised 16 biomarkers representing cardiometabolic, glucose, cardiopulmonary, parasympathetic, and inflammatory systems (higher scores = greater dysregulation). Cognitive outcomes included GC and individual tests of verbal learning and memory, world fluency (WF), Digit Symbol Substitution (DSS), and Trail Making (Parts A & B). Survey-linear regressions assessed associations of AL with performance in cognition at baseline, 7 years later, and via 7-year cognitive change scores adjusting for sociodemographic characteristics, lifestyle factors, and depressive symptoms. Results: Higher AL was associated with lower baseline performance in GC and WF; and lower 7-year follow-up performance in these same measures plus DSS and Trail Making Parts A & B. Higher AL was associated with more pronounced 7-year change (reduction) in GC and on WF and DSS tests. Conclusions: Findings extend previous evidence in predominantly older non-Hispanic white cohorts to show that AL is related to level of and change in GC (as well as WF and DSS) among middle-aged and older US-based Hispanic/Latino adults.

Cardiovascular disease risk exacerbates brain aging among Hispanic/Latino adults in the SOL-INCA-MRI Study.

Background: Cardiovascular disease (CVD) risk factors are highly prevalent among Hispanic/Latino adults, while the prevalence of MRI infarcts is not well-documented. We, therefore, sought to examine the relationships between CVD risk factors and infarcts with brain structure among Hispanic/Latino individuals. Methods: Participants included 1,886 Hispanic/Latino adults (50-85 years) who underwent magnetic resonance imaging (MRI) as part of the Study of Latinos-Investigation of Neurocognitive Aging-MRI (SOL-INCA-MRI) study. CVD risk was measured approximately 10.5 years before MRI using the Framingham cardiovascular risk score, a measure of 10-year CVD risk (low (<10%), medium (10- < 20%), and high (≥20%)). MR infarcts were determined as present or absent. Outcomes included total brain, cerebral and lobar cortical gray matter, hippocampal, lateral ventricle, and total white matter hyperintensity (WMH) volumes. Linear regression models tested associations between CVD risk and infarct with MRI outcomes and for modifications by age and sex. Results: Sixty percent of participants were at medium or high CVD risk. Medium and high CVD risk were associated with lower total brain and frontal gray matter and higher WMH volumes compared to those with low CVD risk. High CVD risk was additionally associated with lower total cortical gray matter and parietal volumes and larger lateral ventricle volumes. Men tended to have greater CVDRF-related differences in total brain volumes than women. The association of CVD risk factors on total brain volumes increased with age, equal to an approximate 7-year increase in total brain aging among the high-CVD-risk group compared to the low-risk group. The presence of infarct(s) was associated with lower total brain volumes, which was equal to an approximate 5-year increase in brain aging compared to individuals without infarcts. Infarcts were also associated with smaller total cortical gray matter, frontal and parietal volumes, and larger lateral ventricle and WMH volumes. Conclusion: The high prevalence of CVD risk among Hispanic/Latino adults may be associated with accelerated brain aging.

Tooth Loss, Periodontal Disease, and Mild Cognitive Impairment Among Hispanic/Latino Immigrants: The Moderating Effects of Age at Immigration.

BACKGROUND: The objectives were to assess (a) the association between poor oral health and mild cognitive impairment (MCI) in Hispanic/Latino immigrants and (b) potential modification effects on this association by age at immigration. METHODS: Data were from the Hispanic Community Health Study/Study of Latinos and its ancillary study-the Study of Latinos-Investigation of Neurocognitive Aging. MCI, a binary outcome variable, defined by the National Institute on Aging-Alzheimer's Association criteria. The main exposure was significant tooth loss (STL), defined as a loss of 8 or more teeth, and periodontitis, classified using the Centers for Disease Control and Prevention and American Academy of Periodontology case classification. Multiple logistic regression was used to assess the association between STL/periodontitis and MCI and test moderation effects of age at immigration. The analytical sample comprised 5 709 Hispanic/Latino adult immigrants. RESULTS: Hispanic/Latino immigrants with STL (adjusted odds ratio [AOR] = 1.36, 95% confidence interval [CI]: 1.01-1.85) were more likely to have MCI than those with greater tooth retention. Overall, migration to the United States after age 18 was associated with greater odds of MCI than migration at a younger age. A significant interaction effect between STL and age at immigration revealed that the effect of STL on MCI is even higher in those who immigrated to the United States at ages 35-49 years. CONCLUSIONS: STL is a significant risk factor for MCI and age at immigration had a modification effect on the association between STL and MCI. Better access to dental care, health education on risk factors of MCI, and promotion of good oral health may mitigate the burden of cognitive impairment in Hispanics/Latinos.

The Mediating Roles of Neurobiomarkers in the Relationship Between Education and Late-Life Cognition.

BACKGROUND: The mediating roles of neuropathologies and neurovascular damage in the relationship between early-life education and later-life cognitive function are unknown. OBJECTIVE: To examine whether Alzheimer's and neurovascular biomarkers mediate the relationships between education and cognitive functions. METHODS: Data were from 537 adults aged 55-94 in the Alzheimer's Disease Neuroimaging Initiative 3. We tested whether the relationships between education (continuous, years) and cognitive function (memory, executive functioning, and language composites) were mediated by neuroimaging biomarkers (hippocampal volumes, cortical gray matter volumes, meta-temporal tau PET standard uptake value ratio, and white matter hyperintensity volumes). Models were adjusted for age, race, sex/gender, cardiovascular history, body mass index, depression, and Apolipoprotein E-ɛ4 status. RESULTS: Hippocampal volumes and white matter hyperintensities partially mediated the relationships between education and cognitive function across all domains (6.43% to 15.72% mediated). The direct effects of education on each cognitive domain were strong and statistically significant. CONCLUSIONS: Commonly measured neurobiomarkers only partially mediate the relationships between education and multi-domain cognitive function.

The Effect of Self-Reported Visual Impairment and Sleep on Cognitive Decline: Results of the Hispanic Community Health Study/Study of Latinos.

BACKGROUND: Visual impairment could worsen sleep/wake disorders and cognitive decline. OBJECTIVE: To examine interrelations among self-reported visual impairment, sleep, and cognitive decline in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Miami-site. METHOD: HCHS/SOL Miami-site participants ages 45-74 years (n = 665) at Visit-1, who returned for cognitive test 7-years later (SOL-INCA). Participants completed the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ), validated sleep questionnaires and test for obstructive sleep apnea (OSA) at Visit-1. We obtained verbal episodic learning and memory, verbal fluency, processing speed, and executive functioning at Visit-1 and at SOL-INCA. Processing speed/executive functioning were added to SOL-INCA. We examined global cognition and change using a regression-based reliable change index, adjusting for the time lapse between Visit-1 and SOL-INCA. We used regression models to test whether 1) persons with OSA, self-reported sleep duration, insomnia, and sleepiness have an increased risk for visual impairment, 2a) visual impairment is associated with worse cognitive function and/or decline, and 2b) sleep disorders attenuate these associations. RESULT: Sleepiness (ß= 0.04; p < 0.01) and insomnia (ß= 0.04; p < 0.001) were cross-sectionally associated with visual impairment, adjusting for sociodemographic characteristics, behavioral factors, acculturation, and health conditions. Visual impairment was associated with lower global cognitive function at Visit-1 (ß= -0.16; p < 0.001) and on average 7-years later (ß= -0.18; p < 0.001). Visual impairment was also associated with a change in verbal fluency (ß= -0.17; p < 0.01). OSA, self-reported sleep duration, insomnia, and sleepiness did not attenuate any of the associations. CONCLUSION: Self-reported visual impairment was independently associated with worse cognitive function and decline.

Associations Between Parity and Cognition: Race/Ethnic Differences.

BACKGROUND: Race/ethnicity is associated with differences in reproductive history and cognition individually, yet it remains an understudied factor in the relationship between parity and later-life cognition. OBJECTIVE: To evaluate if the association between parity and cognition differs between racial/ethnic groups. METHODS: Participants included 778 older, postmenopausal women from the Health and Nutrition Examination Survey (Latina: n = 178, Non-Latino Black [NLB]: n = 169, Non-Latino White [NLW]: n = 431) who self-reported at least one birth. Cognitive outcomes included working memory, learning memory, and verbal fluency. Covariates included age, education, cardiovascular and other reproductive health factors, adult socioeconomic status (SES) and depressive symptoms. We fit a series of linear models to examine a) whether parity was associated with cognitive functioning, b) if this association varied by race/ethnicity through parity by race/ethnicity interactions, and c) individual parity with cognition associations stratified by race/ethnicity. RESULTS: In the full sample, parity was significantly negatively associated with Digit Symbol Substitution Test (DSST) performance (b = -0.70, p = 0.024) but not Animal Fluency or word-list learning and memory. Tests of race/ethnicity-by-parity interactions were not statistically significant (ps > 0.05). However, stratified analyses by race/ethnicity showed a differential effect of parity on DSST performance, such that parity was significantly negatively associated with DSST performance (b = -1.66, p = 0.007) among Latinas but not in NLWs (b = -0.16, p = 0.74) or NLBs (b = -0.81, p = 0.191). CONCLUSION: Among Latina, but not NLB or NLW women, greater parity was associated with worse processing speed/executive functioning later in life. Further research is needed to understand the mechanisms driving racial/ethnic differences.