AbstractIntroductionEarly detection of cognitive decline in older adults is a public health priority. Advancing Reliable Measurement in Alzheimer's Disease and Cognitive Aging (ARMADA), a multisite study, is validating cognition, emotion, motor, and sensory modules of the National Institutes of Health Toolbox for Assessment of Neurological and Behavioral Function (NIHTB) in the aging spectrum from cognitively normal to dementia of the Alzheimer's type (DAT).MethodsParticipants 65 to 85 years old, in demographic groups racially proportional to the general US population, are recruited in one of three groups to validate the NIHTB: cognitively normal, amnestic mild cognitive impairment (aMCI), or mild DAT. Additional special emphasis cohorts include (1) Blacks in the three clinical groups; (2) Spanish‐speakers in the three clinical groups; (3) cognitively normal, population‐proportional, over age 85.DiscussionLongitudinal study will determine whether NIHTB can predict cognitive decline and is associated with Alzheimer's disease biomarkers. Here, we detail the methods for the ARMADA study.
Association Between Blood Pressure and Later-Life Cognition Among Black and White Individuals
Importance Black individuals are more likely than white individuals to develop dementia. Whether higher blood pressure (BP) levels in black individuals explain differences between black and white individuals in dementia risk is uncertain. Objective To determine whether cumulative BP levels explain racial differences in cognitive decline. Design, Setting, and Participants Individual participant data from 5 cohorts (January 1971 to December 2017) were pooled from the Atherosclerosis Risk in Communities Study, Coronary Artery Risk Development in Young Adults Study, Cardiovascular Health Study, Framingham Offspring Study, and Northern Manhattan Study. Outcomes were standardized as t scores (mean [SD], 50 [10]); a 1-point difference represented a 0.1-SD difference in cognition. The median (interquartile range) follow-up was 12.4 (5.9-21.0) years. Analysis began September 2018. Main Outcomes and Measures The primary outcome was change in global cognition, and secondary outcomes were change in memory and executive function. Exposures Race (black vs white). Results Among 34 349 participants, 19 378 individuals who were free of stroke and dementia and had longitudinal BP, cognitive, and covariate data were included in the analysis. The mean (SD) age at first cognitive assessment was 59.8 (10.4) years and ranged from 5 to 95 years. Of 19 378 individuals, 10 724 (55.3%) were female and 15 526 (80.1%) were white. Compared with white individuals, black individuals had significantly faster declines in global cognition (−0.03 points per year faster [95% CI, −0.05 to −0.01]; P = .004) and memory (−0.08 points per year faster [95% CI, −0.11 to −0.06]; P < .001) but significantly slower declines in executive function (0.09 points per year slower [95% CI, 0.08-0.10]; P < .001). Time-dependent cumulative mean systolic BP level was associated with significantly faster declines in global cognition (−0.018 points per year faster per each 10–mm Hg increase [95% CI, −0.023 to −0.014]; P < .001), memory (−0.028 points per year faster per each 10–mm Hg increase [95% CI, −0.035 to −0.021]; P < .001), and executive function (−0.01 points per year faster per each 10–mm Hg increase [95% CI, −0.014 to −0.007]; P < .001). After adjusting for cumulative mean systolic BP, differences between black and white individuals in cognitive slopes were attenuated for global cognition (−0.01 points per year [95% CI, −0.03 to 0.01]; P = .56) and memory (−0.06 points per year [95% CI, −0.08 to −0.03]; P < .001) but not executive function (0.10 points per year [95% CI, 0.09-0.11]; P < .001). Conclusions and Relevance These results suggest that black individuals’ higher cumulative BP levels may contribute to racial differences in later-life cognitive decline.
Abstract TMP110: Design of the BP-COG Study of Blood Pressure Over the Life Course and Later-Life Cognition in Blacks, Hispanics, and Whites: A Pooled Cohort Analysis of ARIC, CARDIA, CHS, FOS, MESA, and NOMAS
Background: High blood pressure (BP), particularly in mid-life, increases the risk for late-life cognitive impairment and dementia (CID). The extent to which Blacks’ and Hispanics’ worse BP control starting in young adulthood contributes to their greater risk of CID compared to Whites is uncertain. Objective: To describe a pooled, multi-ethnic cohort created to determine the associations between BP levels over the life course and CID risk in Blacks, Hispanics, and Whites. Methods: We pooled individual-level data from 35,473 adults (22.6% Blacks, 8.1% Hispanics, 67.3% Whites, 2% Other) with baseline age ≥18 and cognitive assessments across 6 longitudinal cohorts in the United States from 1971 to 2016: Atherosclerosis Risk in Communities Study (ARIC), Coronary Artery Risk Development in Young Adults Study (CARDIA), Cardiovascular Health Study (CHS), Framingham Offspring Study (FOS), Multi-Ethnic Study of Atherosclerosis (MESA), and Northern Manhattan Study (NOMAS). We harmonized cognitive tests across studies into 3 factors representing global cognitive performance, executive function, and memory using statistically appropriate confirmatory factor analysis. Mean (SD) follow up was 17.1 (10.9) years. Results: The mean (SD) baseline age was 54.3 (16.4) years and 19554 (55.1%) participants were female (Table). There were 3193 (9.0%) first incident strokes (2651 ischemic, 348 hemorrhagic, and 117 other or undetermined type) and 15147 (42.7%) deaths. The Table presents mean BPs at the first and last visits by cohort and the pooled sample. From the initial to the last assessment, mean global cognition decreased over time (p<0.001), as did mean executive function (p<0.001) and mean memory scores (p<0.001) in the pooled sample. Conclusion: This will be the first comprehensive, large investigation of the association of BP levels from young adulthood to late-life and CID risk in Blacks, Hispanics, and Whites.
Effect of Nitrous Oxide Use on Long-term Neurologic and Neuropsychological Outcome in Patients Who Received Temporary Proximal Artery Occlusion during Cerebral Aneurysm Clipping Surgery
Background The authors explored the relationship between nitrous oxide use and neurologic and neuropsychological outcome in a population of patients likely to experience intraoperative cerebral ischemia: those who had temporary cerebral arterial occlusion during aneurysm clipping surgery. Methods A post hoc analysis of a subset of the data from the Intraoperative Hypothermia for Aneurysm Surgery Trial was conducted. Only subjects who had temporary arterial occlusion during surgery were included in the analysis. Metrics of short-term and long-term (i.e., 3 months after surgery) outcome were evaluated via both univariate and multivariate logistic regression analysis. An odds ratio (OR) greater than 1.0 denotes a worse outcome in patients receiving nitrous oxide. Results The authors evaluated 441 patients, of which 199 received nitrous oxide. Patients receiving nitrous oxide had a greater risk of delayed ischemic neurologic deficits (i.e., the clinical manifestation of vasospasm) (OR, 1.78, 95% confidence interval [CI], 1.08-2.95; P = 0.025). However, at 3 months after surgery, there was no difference in any metric of gross neurologic outcome: Glasgow Outcome Score (OR, 0.67; CI, 0.44-1.03; P = 0.065), Rankin Score (OR, 0.74; CI, 0.47-1.16; P = 0.192), National Institutes of Health Stroke Scale (OR, 1.02; CI, 0.66-1.56; P = 0.937), or Barthel Index (OR, 0.69; CI, 0.38-1.25; P = 0.22). The risk of impairment on at least one test of neuropsychological function was reduced in those who received nitrous oxide (OR, 0.56; CI, 0.36-0.89; P = 0.013). Conclusion In this patient population, use of nitrous oxide was associated with an increased risk for the development of delayed ischemic neurologic deficits; however, there was no evidence of detriment to long-term gross neurologic or neuropsychological outcome.