Characterization of African-American Super-Agers in the National Alzheimer's Coordinating Center cohort.

BACKGROUND: "Super-agers" are adults aged ≥80 with cognitive performance similar to persons two to three decades younger. Characteristics such as larger hippocampal volume, APOE-ε4 allele absence, higher educational attainment, female sex, and lifelong cognitive stimulation are associated with cognitive performance compatible with super-aging. These findings are based on predominantly white research samples. Limited data are available on African-American super-agers. To fill this gap, we explored potential factors associated with super-aging in older African-American adults. METHODS: Data from African-American participants aged ≥80 in the National Alzheimer's Coordinating Center (NACC) dataset were analyzed. Using global Clinical Dementia Rating (CDR) scores, participants were first categorized as impaired (score ≥0.5) or non-impaired/normal cognition (NC) (score = 0). From the NC group, super-agers were identified using NACC-data-driven cutoffs. Participants were considered super-agers if their memory performance was similar to persons aged 50-60 with NC, and their performance on other domains was within one standard deviation of the mean for persons aged ≥80. We examined group characteristics (NC, super-ager, impaired) using chi-square and ANOVA with pairwise comparisons. Multinomial logistic regression, adjusted for sex and education, evaluated correlates of super-ager group assignment. RESULTS: Data for 1285 African-American participants aged ≥80 were analyzed. We identified 24.7% (n = 316) NC, 4.8% (n = 61) super-agers, and 70.6% (n = 905) impaired. Super-agers were mostly female and more educated, had similar vascular comorbidities as the other groups, and had less sleep disorders, depression, and alcohol use. After adjusting for sex and education, super-ager group assignment was associated with less sleep disorders, less depression, and moderate alcohol use. CONCLUSIONS: Participants with controlled vascular risk, mental health, alcohol use, and sleep disorders tended to be in the super-ager group. These factors may be important focus areas in clinical practice to support cognitive resilience with aging in older African-American adults.

Racial Disparity in Cerebrospinal Fluid Amyloid and Tau Biomarkers and Associated Cutoffs for Mild Cognitive Impairment.

Importance: Prior evidence suggests that racial differences exist in tau biomarkers in mild cognitive impairment (MCI) and Alzheimer disease (AD). Whether this reported disparity is associated with a differential level of neurodegeneration and disease stage or with underlying mechanisms separate from amyloid or tau is unclear. Objectives: To compare cerebrospinal fluid (CSF) biomarkers in African American and white individuals with normal cognition and MCI, to estimate race-based cutoffs for these biomarkers that maximize diagnostic discrimination between normal cognition and MCI, and to study the association of demographic characteristics, cognitive performance, and common vascular risk factors with these differences. Design, Setting, and Participants: This case-control study conducted from March 1, 2016, through January 31, 2019, included participants in the Brain Stress Hypertension and Aging Research Program cohort undergoing baseline assessment. Participants were 50 years or older and recruited from the Atlanta, Georgia, area. Exposures: Self-reported race and cognitive status categorized using modified Petersen criteria and clinical consensus diagnosis. Main Outcomes and Measures: Levels of ß-amyloid 1-42 (Aß1-42), tau, and phosphorylated tau 181 (pTau181), the ratio of tau or pTau181 to Aß1-42, and hippocampal volume on magnetic resonance imaging of the brain. Results: Data from 362 study participants were analyzed (mean [SD] age, 65.6 [7.9] years), of whom 152 (42.0%) were African American, 230 (63.5%) were women, and 189 (52.2%) had MCI. After adjustment for demographic characteristics and cognitive performance, lower mean (SE) levels were observed in African American vs white individuals with MCI for tau (52.40 [5.90] vs 78.98 [5.02] pg/mL; P = .001) and pTau181 (15.42 [2.06] vs 25.24 [1.75] pg/mL; P = .001) and a lower pTau181 to Aß1-42 ratio (0.07 [0.02] vs 0.14 [0.01]; P = .003). There were no racial differences in the normal cognition group or in hippocampal volumes in the MCI group. Cutoffs for CSF biomarkers were higher for Aß1-42 in African American relative to white individuals (208 [95% CI, 126-321] vs 197 [95% CI, 183-245] pg/mL) and lower for tau (51 [95% CI, 31-59] vs 59 [95% CI, 56-92] pg/mL) and pTau181 (12 [95% CI, 12-19] vs 20 [95% CI, 12-27] pg/mL) levels. Cutoffs for the pTau181 to Aß1-42 ratio were 0.05 (95% CI, 0.03-0.12) for African American participants and 0.05 (95% CI, 0.05-0.13) for white participants. Conclusions and Relevance: This study found that African American individuals had lower levels of tau-based biomarkers that were not likely explained by the degree of disease stage or neurodegeneration reflected by hippocampal volumes. This study suggests that race is an important factor when interpreting CSF biomarkers, especially in the clinical diagnosis of prodromal AD. It appears that using the pTau181 to Aß1-42 ratio may ameliorate these differences.

Assessment of cerebrovascular reactivity during resting state breathing and its correlation with cognitive function in hypertension.

BACKGROUND: Hypertension is associated with cognitive deficits, particularly executive function, and decreased cerebral microvascular responsiveness to CO2 (CO2 vasoreactivity). The relation between CO2 vasoreactivity and executive function is not known. Protocols to assess CO2 vasoreactivity are cumbersome and require inhaling a CO2-enriched gas. We explored the ability to measure CO2 vasoreactivity using end-tidal CO2 fluctuations during normal breathing and the association of this measure with cognitive function in hypertension. METHODS: Executive function (Trail-Making Test parts A/B), memory, attention and blood flow velocity (BFV) in the middle cerebral artery using transcranial Doppler were measured in hypertensive subjects who were tapered off their treatment for 3 weeks. BFV was measured while sitting and normally breathing for 5 min, followed by breathing 5% CO2 gas and hyperventilation for 2 min each. We calculated CO2 vasoreactivity as the rate of BFV change from hypoventilation to hyperventilation, and as a model-derived measure using the normal breathing data. The latter was derived using nonlinear principal dynamic modes (PDM), which modelled the dynamic effect of fluctuations in end-tidal CO2 and blood pressure upon BFV during normal room-air respiration. Multiple regression analyses were used to correlate cerebral hemodynamics with cognitive measures. RESULTS: Data were collected from 41 individuals with hypertension (mean age 71 years, 24% African Americans, 61% women, off antihypertensive therapy). Lower CO2 vasoreactivity was associated with a worse executive function test score using both calculation methods: p value using the hyper/hypoventilation data was 0.04 and from the PDM analysis was 0.009. PDM calculations showed a stronger correlation with executive function (0.41 vs. 0.21 using the hyper/hypoventilation data). There were no associations with memory or attention measures. There was a weak but statistically significant correlation between the two calculation methods of CO2 vasoreactivity (R(2) = 14%, p = 0.02). CONCLUSION: This study suggests that the decrease in CO2 vasoreactivity in hypertension is associated with lower executive function. This may offer new insight into the vascular underpinning of cognitive decline in hypertension. We demonstrate that calculating CO2 vasoreactivity is possible during normal breathing. If replicated in future studies, this may offer a more convenient clinical way to assess CO2 vasoreactivity in hypertension and cognitive disorders.

In situ monitoring of health in older adults: technologies and issues.

With the upcoming reform of the healthcare system and the greater emphasis on care in the home and other living environments, geriatric providers will need alternate ways of monitoring disease, activity, response to therapy, and patient safety. Current understanding of the dynamic nature of chronic illnesses, their effects on health over time, and the ability to manage them in the community are limited to measuring a set of variables at discrete points in time, which does not account for the dynamic interactions between physiological systems and the environments of daily life. Recent developments of sensors, data recorders, and communication networks allow the unprecedented measurements of physiological and sociological data for use in geriatrics care. This article identifies and discusses the important issues regarding the use of monitoring technologies in elderly patients. The goals are fourfold. First, some emerging technology that may improve the lives of older adults and improve care are highlighted. Second, the possible applications of technology in geriatrics settings are discussed, with a focus on acute falls, dementia, and cardiac conditions. Third, real and perceived concerns in using monitoring technology are identified and addressed, including technology adoption by elderly people; stigma; and the reduction in social contact; ethical concerns of privacy, autonomy, and consent; concerns of clinicians, including information overload, licensure, and liability; current reimbursement schemes for using technology; and the reliability and infrastructure needed for monitoring technology. Fourth, future approaches to make monitoring technology useful and available in geriatrics are recommended.

Hypertension: trends in prevalence, incidence, and control.

Hypertension is the leading cause of cardiovascular disease worldwide. Prior to 1990, population data suggest that hypertension prevalence was decreasing; however, recent data suggest that it is again on the rise. In 1999-2002, 28.6% of the U.S. population had hypertension. Hypertension prevalence has also been increasing in other countries, and an estimated 972 million people in the world are suffering from this problem. Incidence rates of hypertension range between 3% and 18%, depending on the age, gender, ethnicity, and body size of the population studied. Despite advances in hypertension treatment, control rates continue to be suboptimal. Only about one third of all hypertensives are controlled in the United States. Programs that improve hypertension control rates and prevent hypertension are urgently needed.

Improving patient outcomes with ambulatory blood pressure monitoring in elderly with hypertension.

PURPOSE: The purpose of this article is to review the current knowledge regarding ambulatory blood pressure monitoring (ABPM) use in clinical practice and to provide example cases for its use in a hypertension (HTN) specialty clinic. DATA SOURCES: Published research trials, medical literature, and cases from the Center for Senior Hypertension. CONCLUSIONS: The knowledge of ABPM benefits to using ABPM are substantial and improves the care and management of many conditions, including white coat HTN, white coat normotension, resistant, borderline, episodic, paroxysmal HTN, and finally orthostatic hypotension. Third-party payers only cover ABPM for "white coat" HTN. IMPLICATIONS FOR PRACTICE: This article reviews previous studies and explains the benefit to changing our current practice to match the knowledge we have gained through research through case studies.