Alzheimer's disease biomarkers in Black and non-Hispanic White cohorts: A contextualized review of the evidence.

Black Americans are disproportionately affected by dementia. To expand our understanding of mechanisms of this disparity, we look to Alzheimer's disease (AD) biomarkers. In this review, we summarize current data, comparing the few studies presenting these findings. Further, we contextualize the data using two influential frameworks: the National Institute on Aging-Alzheimer's Association (NIA-AA) Research Framework and NIA's Health Disparities Research Framework. The NIA-AA Research Framework provides a biological definition of AD that can be measured in vivo. However, current cut-points for determining pathological versus non-pathological status were developed using predominantly White cohorts-a serious limitation. The NIA's Health Disparities Research Framework is used to contextualize findings from studies identifying racial differences in biomarker levels, because studying biomakers in isolation cannot explain or reduce inequities. We offer recommendations to expand study beyond initial reports of racial differences. Specifically, life course experiences associated with racialization and commonly used study enrollment practices may better account for observations than exclusively biological explanations.

Cardiometabolic outcomes in Kronos Early Estrogen Prevention Study continuation: 14-year follow-up of a hormone therapy trial.

OBJECTIVE: This study aimed to determine long-term cardiometabolic effects of hormone therapies initiated within 3 years of onset of menopause after a 14-year follow-up study of participants of the Kronos Early Estrogen Prevention Study (KEEPS). METHODS: KEEPS was a multisite clinical trial that recruited recently menopausal women with good cardiovascular health for randomization to oral conjugated equine estrogens (Premarin, 0.45 mg/d) or transdermal 17ß-estradiol (Climara, 50 µg/d) both with micronized progesterone (Prometrium, 200 mg/d) for 12 d/mo, or placebo pills and patch for 4 years. KEEPS continuation recontacted KEEPS participants 14 years after randomization and 10 years after the completion of the 4-year clinical trial to attend in-person clinic visits. RESULTS: Participants of KEEPS continuation (n = 299 of the 727 KEEPS participants; 41%) had an average age of 67 years (range, 58-73 y). Measurements of systolic and diastolic blood pressures, waist-to-hip ratio, fasting levels of glucose, insulin, lipid profiles, and homeostasis model assessment of insulin resistance were not different among the treatment groups at either KEEPS baseline or at KEEPS continuation visits, or for change between these two visits. The frequency of self-reported diabetes ( P = 0.007) and use of diabetes medications was higher in the placebo than the oral conjugated equine estrogens ( P = 0.045) or transdermal 17ß-estradiol ( P = 0.02) groups, but these differences were not supported by the laboratory measurements of glycemia or insulin resistance. CONCLUSIONS: There was no evidence of cardiovascular and/or metabolic benefits or adverse effects associated with 4 years use of oral or transdermal forms of hormone therapy by recently menopausal women with good cardiovascular health after 10 years.

Wisconsin Healthcare Utilization Cost Among American Indians/Alaska Natives with and without Alzheimer's Disease and Related Dementias.

Individuals with Alzheimer's disease and related dementias (ADRD) accrue higher healthcare utilization costs than peers without ADRD, but incremental costs of ADRD among American Indians/Alaska Natives (AI/AN) is unknown. State-wide paid electronic health record data were retrospectively analyzed using percentile-based bootstrapped 95% confidence intervals of the weighted mean difference of total 5-year billed costs to compare total accrued for non-Tribal and Indian Health Service utilization costs among Medicaid and state program eligible AI/AN, ≥40 years, based on the presence/absence of ADRD (matching by demographic and medical factors). AI/AN individuals with ADRD accrued double the costs compared to those without ADRD, costing an additional $880.45 million to $1.91 billion/year.

Effect of Metabolic Syndrome Risk Factors on Processing Speed and Executive Function in Three Racialized Groups.

BACKGROUND: Metabolic syndrome (MetS) has been associated with increased risk for Alzheimer's disease and related dementias (ADRD). Understanding the association of MetS risk factors to processing speed and executive function in the pre-clinical stages of ADRD in under-represented groups would offer insight on potential mechanisms through which MetS associates with ADRD risk. OBJECTIVE: Examine association of MetS features and processing speed and executive function across three racial groups. METHODS: Cognitively unimpaired adults from the Wisconsin Alzheimer's Disease Research Center and the Wisconsin Registry for Alzheimer's Disease Prevention completed blood-draws and neuropsychological testing. Six cognitive outcomes were assessed in association to MetS risk factors: Trailmaking Tests A and B, Animal Fluency, Digit Symbol, and composite scores for Processing Speed and Executive Function. Linear mixed effect models were used to assess the relationship between MetS risk factor count and longitudinal cognitive performance across three racialized groups. RESULTS: Participant sample sizes varied by outcome analyzed (N = 714-1,088). African American and Native American groups exhibited higher rates of MetS than non-Hispanic Whites. MetS was associated with processing speed and executive function across all racialized groups. Three-way interaction by racialized group was limited to one cognitive outcome: Trailmaking Test A. CONCLUSION: Metabolic dysfunction incrementally affects cognitive trajectory, with generally similar associations across racial groups. Since racialized groups exhibit higher levels of both MetS and ADRD, MetS may represent a driving factor for increased ADRD risk experience by racialized group and an important and modifiable target through which to reduce risk of ADRD.

Associations between pituitary-ovarian hormones and cognition in recently menopausal women independent of type of hormone therapy.

OBJECTIVES: To examine associations of pituitary-ovarian hormone levels with cognition before and after different formulations of hormone therapy (HT) or placebo independent of treatment group. METHODS: Recently menopausal, healthy women were randomized to 0.45 mg/day oral conjugated equine estrogens (o-CEE, n = 109), 50 µg/day transdermal 17ß (tE2, n = 107) or placebo pills and patches (n = 146); women on active treatment received oral 200 mg/day micronized progesterone for 12 days per month. Levels of estrone, 17ß-estradiol, follicle stimulating hormone, luteinizing hormone, androstenedione, and testosterone were determined prior to and after 48 months of study participation. Neuropsychological testing was administered at baseline, and months 18, 36 and 48. Latent growth curve models controlling for education level, age, APOE allele status, waist circumference, and treatment examined the trajectories of each cognitive domain after accounting for the effect of hormone levels at baseline and months 18, 36 and 48. A linear multivariate mixed model examined the effect of changes in hormone levels on changes in trajectories of complex attention tasks with varying degrees of difficulty. RESULTS: All women were adherent to treatment at month 48. Higher baseline estrone levels were associated with poorer global cognition, auditory attention and working memory, visual attention, and executive function, but not working memory. Higher levels of baseline 17ß-E2 were associated with poorer cognitive performance, with marginal significance at baseline in speeded language and mental flexibility (p = 0.013). Other hormone levels were not associated with cognition. Controlling for all treatments, hormone levels at baseline and at month 48 did not have any significant correlation with cognitive trajectories over time. SUMMARY: In healthy, recently menopausal women, baseline estrone levels were inversely associated with selected cognitive factors independent of two types of HT or placebo during 4 years of follow-up. Baseline levels of the other pituitary-ovarian hormones studied were not associated with baseline cognition, nor were changes in any hormones associated with changes in cognition during the study. The marginal association between estradiol levels and cognitive factors warrants further investigation. GOV NUMBERS: NCT00154180, NCT00623311.

Histone H3 phosphorylation (Ser10, Ser28) and phosphoacetylation (K9S10) are differentially associated with gene expression in liver of rats treated in vivo with acute ethanol.

The epigenetic histone modification by ethanol is emerging as one of the mechanisms for its deleterious effects in the liver. In this context, we have investigated the role of histone H3 phosphorylation at Ser10 (P-H3-Ser10), and Ser28 (P-H3-Ser28) in liver after acute ethanol treatment in vivo. Ethanol was administered intraperitoneally in male Sprague-Dawley rats. Ethanol dose-response (1-5 g/kg body weight) and time-course (1-4 h) experiments were conducted, and various parameters were monitored. Steatosis and necrosis (serum alanine aminotransferase) of the liver increased in 4 h, suggesting liver injury. There were differences between P-H3-Ser10 and P-H3-Ser28 at 1 h, with the latter being more sensitive to lower ethanol doses. It was noteworthy that phosphorylation of both serines disappeared at the highest dose used (5 g/kg). We also examined phosphoacetylation of histone H3 at K9S10 and observed a dramatic increase. The changes in histone H3 phosphorylation and phosphoacetylation were also accompanied with expression of early response genes (c-fos, c-jun, mitogen-activated protein kinase phosphatase-1). Chromatin immunoprecipitation assays in samples from 1.5 and 4 h of ethanol administration indicated that increased histone H3 phosphorylation at Ser28 was associated with the promoters of c-jun and plasminogen activator inhibitor-1. In conclusion, this study demonstrates for the first time that in vivo exposure of liver to acute ethanol induced phosphorylation and phosphoacetylation of histone H3, and these modifications are differentially involved in the mRNA expression of genes.

Cardiometabolic measures and cognition in early menopause - Analysis of baseline data from a randomized controlled trial.

OBJECTIVE: The relationships between cardiometabolic indices and cognition were examined in recently menopausal women. METHODS: Cross-sectional analysis of baseline data from the KEEPS (Kronos Early Estrogen Prevention Study)-Cognitive ancillary study (n = 621). Cognitive performance was assessed by the Modified Mini Mental Status (3MS) score (primary outcome). Physical cardiometabolic indices included body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and blood pressure (BP). Biochemical cardiometabolic indices included serum levels of high sensitivity C-reactive protein (hs-CRP), total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), non-HDL (non-HDL-C), triglycerides (TG), fasting serum glucose (FSG), and insulin resistance (HOMA-IR). Socio-demographic variables included age, race/ethnicity, education, and lifestyle (physical activity, smoking). Central adiposity was defined as WC > 88 cm (>35 in) and WHR > 0.8. Separate stepwise multivariable analyses (GLM, ordinal logistic regression and logistic regression) assessed relationships between 3MS scores (as continuous, in tertiles and dichotomized at 90 respectively) with the measures of central adiposity (predictor variables); socio-demographic variables (age, time since menopause, race, educational status and lifestyle) and cardiometabolic variables (BP, lipids, FSG, HOMA-IR and hs-CRP) were examined as covariates. The final multivariable models included time since menopause, race, ethnicity, educational status, strenuous exercise, BMI ≥30 kg/m2, non-HDL-C and hs-CRP as covariates. Due to the high collinearity between the two indices of central adiposity, within each analytic strategy, separate models examined the respective associations of WC > 88 cm and WHR > 0.8 with 3MS score. RESULTS: On adjusted analyses, indices of central adiposity were independent predictors of significantly lower 3MS scores (p < 0.05). Consistency in this relationship was observed across the three different multivariable regression analytic approaches (GLM, ordinal and logistic regression). CONCLUSIONS: Among recently menopausal women, WC > 88 cm and WHR > 0.8 were associated with significantly lower cognitive function, as reflected by lower 3MS scores. The mechanisms that might explain the observed negative implications of central adiposity for cognitive function warrant further study.

Racial Differences in Associations of Cognitive Health Status With Happiness, Helplessness, and Hopelessness Among Older Adults: An Exploratory Study.

Background: The relationship between healthy and positive aging and dementia and cognitive impairment has received limited attention in the field of aging. Affect impacts cognitive changes and processes, and cognitive impairment is associated with affective comorbidities. The purpose of the study was to examine (a) whether happiness, helplessness, and hopelessness are linked to cognitive health status, and (b) whether these associations differ by race. Methods: Participants were enrollees in the Wisconsin Alzheimer's Disease Research Center's Clinical Core (ADRC). Average age at baseline was 60.85 (SD = 8.65), 73.70 (SD = 8.02), and 73.80 (SD = 9.59) years for cognitively normal individuals, individuals with MCI, and individuals with dementia, respectively. Results: In the full sample, chi-square test results revealed associations between Cognitive Health Status (CHS) and (a) happiness, χ2(2) = 6.06, p < 0.05, (b) helplessness, χ2(2) = 6.44, p < 0.05, and (c) hopelessness, χ2(2) = 14.11, p < 0.01. Conclusion: This study provides support for the association of both positive and negative affect with cognitive health status in middle- to older-aged adults.

Sleep quality and cortical amyloid-ß deposition in postmenopausal women of the Kronos early estrogen prevention study.

Hormone therapy improves sleep in menopausal women and recent data suggest that transdermal 17ß-estradiol may reduce the accumulation of cortical amyloid-ß. However, how menopausal hormone therapies modify the associations of amyloid-ß accumulation with sleep quality is not known. In this study, associations of sleep quality with cortical amyloid-ß deposition and cognitive function were assessed in a subset of women who had participated in the Kronos early estrogen prevention study. It was a randomized, placebo-controlled trial in which recently menopausal women (age, 42-58; 5-36 months past menopause) were randomized to (1) oral conjugated equine estrogen (n = 19); (2) transdermal 17ß-estradiol (tE2, n = 21); (3) placebo pills and patch (n = 32) for 4 years. Global sleep quality score was calculated using Pittsburgh sleep quality index, cortical amyloid-ß deposition was measured with Pittsburgh compound-B positron emission tomography standard uptake value ratio and cognitive function was assessed in four cognitive domains 3 years after completion of trial treatments. Lower global sleep quality score (i.e., better sleep quality) correlated with lower cortical Pittsburgh compound-B standard uptake value ratio only in the tE2 group (r = 0.45, P = 0.047). Better global sleep quality also correlated with higher visual attention and executive function scores in the tE2 group (r = -0.54, P = 0.02) and in the oral conjugated equine estrogen group (r = -0.65, P = 0.005). Menopausal hormone therapies may influence the effects of sleep on cognitive function, specifically, visual attention and executive function. There also appears to be a complex relationship between sleep, menopausal hormone therapies, cortical amyloid-ß accumulation and cognitive function, and tE2 formulation may modify the relationship between sleep and amyloid-ß accumulation.

Differential changes in MAP kinases, histone modifications, and liver injury in rats acutely treated with ethanol.

BACKGROUND: Acute ethanol is known to affect cells and organs but the underlying molecular mechanisms are poorly explored. Recent developments highlight the potential importance of mitogen-activated protein kinases, MAPKs (i.e., ERK1/2, p38, and JNK1/2) signaling, and histone modifications (i.e., acetylation, methylation, and phosphorylation) in the actions of ethanol in hepatocytes. We have therefore investigated significance of these molecular steps in vivo using a model in which rats were acutely administered ethanol intraperitoneally (IP). METHODS: Ethanol was administered IP (3.5 gm/kg body weight) to 12-week-old male Sprague-Dawley rats. Liver was subsequently removed at 1 and 4 hours. Serum was used for alcohol and ALT assays. At the time of the removal of liver, small portions of each liver were formalin-fixed and stained with hematoxylin and eosin (H&E) and used for light microscopy. Western blot analysis was carried out with specific primary antibodies for various parameters. RESULTS: There were clear differences at 1 and 4 hours in blood ethanol, ALT, steatosis, and cleaved caspase 3. Apoptosis at 1 hour was followed by necrosis at 4 hours. Acute alcohol elicited a marked increase in the phosphorylation of ERK1/2 and moderate increases in the phosphorylation of p38 MAPK and JNK. Temporally different phosphorylation of histone H3 at ser-10 and ser-28 occurred and acetylation of histone H3 at lys 9 increased progressively. CONCLUSIONS: There were distinct differences in the behavior of the activation of the 3 MAP kinases and histone modifications after acute short exposure of liver to ethanol in vivo. Although all 3 MAPKs were rapidly activated at 1 hour, the necrosis, occurring at 4 hours, correlated to sustained activation of ERK1/2. Transient activation of p38 is associated with rapid phosphorylation of histone H3, whereas prolonged activation of ERK1/2 is correlated to persistent histone H3 acetylation.