Mild Behavioral Impairment as a Marker of Cognitive Decline in Cognitively Normal Older Adults.

OBJECTIVE: Mild behavioral impairment (MBI) is a neurobehavioral syndrome characterized by later life emergent neuropsychiatric symptoms (NPS) that represent an at-risk state for incident cognitive decline and dementia in people with mild cognitive impairment (MCI). We undertook a study to determine whether MBI was associated with progressive changes in neuropsychological performance in people without significant cognitive impairment. METHODS: A total of 9,931 older adults enrolled in the PROTECT study who did not have MCI or dementia undertook a comprehensive neuropsychological battery measuring attention, reasoning, executive function, and working memory at baseline and 1 year. MBI was ascertained using self-administration of the Mild Behavioral Impairment Checklist at 1 year, and participants were grouped according to MBI status: No Symptoms, Intermediate NPS and MBI. All assessments were completed online, and data analyzed using mixed-effects model repeated measures analysis of covariance. RESULTS: A total of 949 (10%) people had MBI. These individuals had significantly worse cognitive performance at baseline and significantly greater decline over 1 year in the four composite cognitive scores measuring attentional intensity (F [2,8578] = 3.97; p = 0.019), sustained attention (F [2,8578] = 18.63; p <0.0001), attentional fluctuation (F [2,8578] = 10.13; p <0.0001) and working memory (F [2,9895] = 13.1; p <0.0001). CONCLUSION: Our novel findings show that MBI is associated with faster decline in attention and working memory in this cognitively normal sample. MBI may be an earlier marker of neurodegenerative disease than MCI, captured at the stage of subjective cognitive decline or before, raising the possibility that MBI represents a novel target for dementia clinical trials or prevention strategies.

An online investigation of the relationship between the frequency of word puzzle use and cognitive function in a large sample of older adults.

OBJECTIVE: The identification of modifiable lifestyle factors to preserve cognitive function in older individuals becomes increasingly of importance. This study examines whether word puzzle use is related to cognitive function in older adults. METHODS: Cognitive data from 19 078 cognitively healthy individuals aged 50 to 93 years enrolled into the online PROTECT study were evaluated for self-reported frequency of performing word puzzles on a six-point scale, ranging from "more than once per day" to "never". Nine cognitive tests covered a range of domains including focussed and sustained attention, information processing, executive function, working memory, and episodic memory. Analyses of covariance were used to determine any differences between the six response groups. RESULTS: Each of the 14 cognitive measures analysed showed highly statistically significant main effects of the frequency of performing word puzzles. For each measure, the group who never performed word puzzles performed most poorly, with the group who reported occasional puzzle use also performing more poorly than virtually every other group. Measures of speed provided the greatest discriminations, with a grammatical reasoning score differentiating the two highest frequency groups, performing word puzzles daily or more than once daily. CONCLUSIONS: The frequency of word puzzle use is directly related to cognitive function in adults aged 50 and over. Future work needs to determine whether engaging in such puzzles can favourably influence cognitive trajectory with age.

The relationship between the frequency of number-puzzle use and baseline cognitive function in a large online sample of adults aged 50 and over.

OBJECTIVE: Establishing affordable lifestyle interventions that might preserve cognitive function in the aging population and subsequent generations is a growing area of research focus. Data from the PROTECT study has been utilised to examine whether number-puzzle use is related to cognitive function in older adults. METHODS: Data from 19 078 healthy volunteers aged 50 to 93 years old enrolled on the online PROTECT study were evaluated for self-reported frequency of performing number puzzles. Two cognitive-test batteries were employed to assess core aspects of cognitive function including reasoning, focussed and sustained attention, information processing, executive function, working memory, and episodic memory. Analysis of covariance was used to establish the differences between the six frequency groups. RESULTS: Highly statistically significant main effects of the frequency of performing number puzzles were seen on all 14 cognitive measures, with P values of less than 0.0004. Interestingly, participants who reported engaging in number puzzles more than once a day had superior cognitive performance on 10 core measures compared with all other frequency groups, although not all were statistically significant. CONCLUSIONS: This study has identified a close relationship between frequency of number-puzzle use and the quality of cognitive function in adults aged 50 to 93 years old. In order to determine the value of these findings as a potential intervention, further research should explore the type and difficulty of the number puzzles. These findings further contribute to the growing evidence that engaging in mentally stimulating activities could benefit the brain function of the ageing population.

The effects of the selective muscarinic M3 receptor antagonist darifenacin, and of hyoscine (scopolamine), on motion sickness, skin conductance & cognitive function.

AIMS: The aim of this study was to compare the effects of the selective M3 muscarinic acetylcholine receptor antagonist darifenacin, oral hyoscine hydrobromide and placebo on motion sickness induced by cross-coupled stimulation. METHODS: The effects of darifenacin 10 mg or 20 mg, hyoscine hydrobromide 0.6 mg and placebo were assessed in a randomized, double-blind, four-way cross over trial of 16 healthy subjects. Motion sickness, skin conductance (a measure of sweating) and psychomotor cognitive function tests were investigated. RESULTS: Hyoscine hydrobromide produced significantly increased tolerance to motion versus placebo (P < 0.05 to P < 0.01). The motion protection effect of darifenacin (10 or 20 mg) was approximately one third that of hyoscine hydrobromide but was not significant versus placebo. Darifenacin and hyoscine hydrobromide both significantly reduced skin conductance versus placebo. Darifenacin produced either no effect or an enhanced effect on cognitive function in contrast to hyoscine hydrobromide, where there was significant impairment of psychomotor performance. CONCLUSION: The results suggest that selective antagonism of the M3 receptor may not be important in the prevention of motion sickness. However, selective M3 antagonism does not impair cognitive function. These observations may be important given that long-term treatment with non-selective anti-muscarinic agents such as oxybutynin may lead to an increased incidence of dementia.

Longitudinal changes in global and domain specific cognitive function in the very-old: findings from the Newcastle 85+ Study.

OBJECTIVE: Ageing is associated with changes in cognition in some, but not all domains. In young-old adults, defined as persons aged 65-84 years, baseline cognitive function has been shown to impact on cognitive trajectories. Whether similar patterns occur in the very-old, defined as persons aged 85 years and over, is not known. METHODS: Longitudinal changes (5 years' follow-up) in global and domain specific cognitive function including memory, attention and speed were investigated in participants from the Newcastle 85+ Study (n = 845). At baseline, participants were grouped using Mini-Mental State Examination cut-off scores and dementia status into the following: not impaired, mildly impaired or severely impaired/dementia groups. RESULTS: Only a limited number of cognitive measures showed significant decline in performance over time. Where observed, change generally occurred only in the severely impaired group. In the severely impaired group, small differences in baseline age were associated with poorer performance over time on most measures. Education was not protective against cognitive decline in any group. CONCLUSIONS: There are individuals who maintain a high level of cognitive function or only show mild impairments even into their ninth decade of life. This group of successful cognitive agers may provide insight for identifying predictors of cognitive integrity in later life. In individuals with severe impairment, cognitive performance shows significant decline over time, especially in measures of attention and speed. Further work to identify those individuals at highest risk of cognitive decline is necessary to implement early support and intervention strategies in this rapidly expanding age group. © 2017 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons Ltd.

Utility, reliability, sensitivity and validity of an online test system designed to monitor changes in cognitive function in clinical trials.

OBJECTIVE: The advent of long-term remotely conducted clinical trials requires assessments which can be administered online. This paper considers the utility, reliability, sensitivity and validity of an internet-based system for measuring changes in cognitive function which is being used in one such trial. METHODS: The Platform for Research Online to investigate Genetics and Cognition in Ageing is a 10-year longitudinal and entirely remote study launched in November 2015. The CogTrackTM System is being used to monitor changes in important aspects of cognitive function using tests of attention, information processing and episodic memory. On study entry, the participants performed CogTrackTM up to three times over seven days, and these data are evaluated in this paper. RESULTS: During the first six months of the study, 14 531 individuals aged 50 to 94 years enrolled and performed the CogTrackTM System, 8627 of whom completed three test sessions. On the first administration, 99.4% of the study tasks were successfully completed. Repeated testing showed training/familiarisation effects on four of the ten measures which had largely stabilised by the third test session. The factor structure of the various measures was found to be robust. Evaluation of the influence of age identified clinically relevant declines over the age range of the population on one or more measures from all tasks. CONCLUSIONS: The results of these analyses identify CogTrackTM to be a practical and valid method to reliably, sensitively, remotely and repeatedly collect cognitive data from large samples of individuals aged 50 and over. Copyright © 2017 John Wiley & Sons, Ltd.

Relationships Among Cognitive Function and Cerebral Blood Flow, Oxidative Stress, and Inflammation in Older Heart Failure Patients.

BACKGROUND: The mechanisms for cognitive impairment in heart failure (HF) are unclear. We investigated the relative contributions of cerebral blood flow velocity (BFV), oxidative stress, and inflammation to HF-associated cognitive impairment. METHODS AND RESULTS: Thirty-six HF patients (≥60 years) and 40 healthy controls (68 ± 7 vs 67 ± 5 years, P > .05; 69% vs 50% male, P > .05) completed the Cognitive Drug Research computerized assessment battery and Stroop tasks. Common carotid (CCA) and middle cerebral arterial BFV were obtained by transcranial Doppler. Blood samples were collected for oxidant (diacron-reactive oxygen metabolites; F2-isoprostanes), antioxidant (coenzyme Q10; CoQ10), and inflammatory markers (high-sensitivity C-reactive protein). Compared with controls, patients exhibited impaired attention (Cognitive Drug Research's Power of Attention domain, congruent Stroop) and executive function (incongruent Stroop). Multiple regression modeling showed that CCA-BFV and CoQ10 but not group predicted performance on attention and executive function. Additionally, in HF patients, CCA-BFV and CoQ10 (ß = -0.34 vs ß = -0.35) were significant predictors of attention, and CCA-BFV (ß = -0.34) was a predictor of executive function. CONCLUSIONS: Power of Attention and executive function is impaired in older HF patients, and reduced CCA-BFV and CoQ10 are associated with worse cognition. Interventions addressing these mechanisms may improve cognition in older HF patients.

Cognitive effects of adjunctive perampanel for partial-onset seizures: A randomized trial.

OBJECTIVE: Assess cognitive effects of adjunctive perampanel in adolescents. METHODS: In this double-blind study (ClinicalTrials.gov identifier: NCT01161524), patients aged 12 to <18 years with partial-onset seizures despite receiving 1-3 antiepileptic drugs were randomized (2:1) to perampanel or placebo. Perampanel was increased weekly in 2-mg increments to 8-12 mg/day (6-week titration; 13-week maintenance). Changes in neuropsychological outcomes were assessed at end of maintenance: Cognitive Drug Research (CDR) System Global Cognition Score (primary end point), five CDR System domain T-scores (secondary end points), letter fluency, category fluency, and Lafayette Grooved Pegboard Test (LGPT). RESULTS: One hundred thirty-three patients were randomized. In the full analysis set, there were no differences of perampanel (n = 79) vs. placebo (n = 44) in CDR System Global Cognition Score (least squares mean change, -0.6 vs. 1.6; p = 0.145), Quality of Working Memory (1.1 vs. 2.0; p = 0.579), or Power of Attention (-6.9 vs. -2.7; p = 0.219). There were small differences with perampanel vs. placebo in other CDR System domains: improvements in Quality of Episodic Memory (3.0 vs. -1.2; p = 0.012), and worsening in Continuity of Attention (-3.3 vs. 1.6; p = 0.013) and Speed of Memory (0.3 vs. 7.0; p = 0.032). Letter fluency, category fluency, and LGPT were not significantly different between groups. The most frequent adverse events with perampanel were dizziness (30.6%) and somnolence (15.3%). SIGNIFICANCE: Perampanel did not differ from placebo in the global cognitive score, two of five subdomains, and four other cognitive measures. Perampanel was worse on two and better on one subdomain.

Single-Dose Interaction Study of the Arginine Vasopressin Type 1B Receptor Antagonist ABT-436 and Alcohol in Moderate Alcohol Drinkers.

BACKGROUND: ABT-436, a potent and selective arginine vasopressin (AVP) type 1B receptor (V1B ) antagonist, has previously demonstrated basal hypothalamic-pituitary-adrenal (HPA) axis attenuation in man. A V1B antagonist is hypothesized as an alcohol-dependent treatment based on the role of the V1B receptor in stress regulation and the finding that stress is a trigger for relapse in alcoholics. A V1B antagonist has shown favorable effects in rat models of alcohol dependence. A single-dose clinical study was conducted to assess the potential for pharmacokinetic or pharmacodynamic interaction between ABT-436 and alcohol. METHODS: Twenty moderate alcohol drinkers each received the 4 possible combinations of a single 1,000 mg ABT-436 dose (or matching placebo) and a single 0.5 g/kg alcohol dose (or placebo for alcohol) in a double-blind, randomized, 4-period crossover study. Plasma ABT-436 and blood alcohol levels were measured to assess pharmacokinetic interactions. A computerized cognitive test battery (CDR System), Bond-Lader Visual Analog Scales scales, and a postural stability test were used to measure the effects of alcohol and the potential interaction with ABT-436. The pharmacologic effect of ABT-436 was assessed by measuring serum cortisol. RESULTS: Neither ABT-436 nor alcohol affected the blood levels of the other. Alcohol reduced performance on 2 of 5 CDR System composite variables (power of attention, p = 0.002; quality of secondary episodic memory, p < 0.001), and decreased postural stability (p = 0.043). ABT-436 did not exacerbate those deleterious effects. ABT-436 reduced serum cortisol (p < 0.001), and alcohol did not significantly diminish this expected effect on the HPA axis. CONCLUSIONS: No pharmacokinetic or pharmacodynamic interaction between ABT-436 and alcohol was observed.

Differences in memory function between 5-HT1A receptor genotypes in patients with major depressive disorder.

BACKGROUND: While extensive literature on the role of the serotonin receptor 1A (5-HT1A-R) in cognition exists, the findings are largely from animal studies. There has been little research conducted into 5-HT1A-R genotypes and cognitive function in humans. This article evaluates the role of 5-HT1A-R genotypes on the profile of cognitive function in patients with major depressive disorder (MDD). METHODS: The study sample was 455 MDD patients aged between 18 and 55 years. They had enrolled into a clinical trial and were tested prior to dosing on the baseline study day using the CDR System, an integrated set of 3 attention tests, 2 working memory tests, and 4 episodic memory tests. 5-HT1A-R genotyping for (SNP ID rs6295) had been conducted during the study screening period. RESULTS: Validated factor scores were derived from the 9 tests. It was found that patients with the C/C genotype for the C(1019)G polymorphism of the 5-HT1A-R were significantly superior in retaining and retrieving information, in both working and episodic memory, than those with either the C/G or the G/G genotypes. No differences were found in measures of attention or in the speed of retrieval of information from memory. CONCLUSIONS: This is, to our knowledge, the first relationship found between objective tests of cognitive function and 5-HT1A-R genotypes in MDD.

Memantine improves attention and episodic memory in Parkinson's disease dementia and dementia with Lewy bodies.

OBJECTIVE: In both dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), attentional dysfunction is a core clinical feature together with disrupted episodic memory. This study evaluated the cognitive effects of memantine in DLB and PDD using automated tests of attention and episodic memory. METHODS: A randomised double-blind, placebo-controlled, 24-week three centre trial of memantine (20 mg/day) was conducted in which tests of attention (simple and choice reaction time) and word recognition (immediate and delayed) from the CDR System were administered prior to dosing and again at 12 and 24 weeks. Although other results from this study have been published, the data from the CDR System tests were not included and are presented here for the first time. RESULTS: Data were available for 51 patients (21 DLB and 30 PDD). In both populations, memantine produced statistically significant medium to large effect sized improvements to choice reaction time, immediate and delayed word recognition. CONCLUSIONS: These are the first substantial improvements on cognitive tests of attention and episodic recognition memory identified with memantine in either DLB or PDD.

An evaluation of the cognitive and mood effects of an energy shot over a 6h period in volunteers: a randomized, double-blind, placebo controlled, cross-over study.

Energy drinks are widely available mostly containing glucose, and several have been demonstrated to improve alertness and cognitive function; these effects generally being identified 30-60min after administration. The present study assessed whether an energy shot without carbohydrates would affect major aspects of cognitive function and also mood in volunteers over a 6h time period. This randomized, double-blind, placebo-controlled,crossover study compared the acute effects of the energy shot with a matching placebo in 94 healthy volunteers. Cognitive function was assessed with a widely used set of automated tests of attention and memory. Mood was assessed with the Bond-Lader, Beck Anxiety Index, Beck Depression Index, Chalder Fatigue Scales (CFS), and the POMS. The volunteers were requested to limit their sleep to between 3 and 6h the night before each testing day. Compared to the placebo, the energy shot significantly improved 6 validated composite cognitive function measures from the CDR System as well as self-rated alertness; the benefits on 4 of the cognitive measures still remaining at 6h. The overall effect sizes of the performance improvements were in the small to medium range and thus notable in this field. In conclusion, an energy shot can significantly improve important aspects of cognitive function for up to 6h compared to placebo in partially sleep-deprived healthy volunteers.

The cognitive profile of type 1 Gaucher disease patients.

BACKGROUND: The absence of neurological symptoms and signs is traditionally considered mandatory for a diagnosis of type 1 Gaucher disease (GD1), but in recent years many reports have emerged on neurological manifestations in GD1 patients. Nevertheless, it has been unclear whether cognitive deficits are part of the disease as well. METHODS: Cognitive function was assessed in a large cohort of GD1 patients with the use of the CDR system, a set of computerised cognitive tests. Testing was performed at baseline and every 6 months thereafter during a two-year study period. RESULTS: Our patient cohort (84 patients, median age 40 years, median time from diagnosis 15 years) showed mild deficits relative to healthy age-matched subjects on the composite scores: power of attention (Z-score (mean ± SD) -0.9 ± 1.37) and speed of memory (Z-score (mean ± SD) -1.39 ± 1.49). No decline in cognitive function was seen during the two-year period. Age correlated with the composite scores variability of attention and quality of working memory. Moreover, severely affected patients (Zimran severity score (SSI) ≥ 15) scored more poorly compared to mildly affected patients (SSI ≤ 5) on the composite measure power of attention, reflecting the ability to concentrate. CONCLUSIONS: GD1 patients exhibit mild deficits in power of attention and speed of memory, reflecting a decreased ability to focus attention and process information, together with a slowing in the speed of retrieval of items from memory. The clinical relevance of these findings is uncertain.

Breakfast is associated with enhanced cognitive function in schoolchildren. An internet based study.

In this study, 1386 children aged between 6 and 16years, from schools throughout the UK, logged on to a web site before lunch during Farmhouse Breakfast Week 2004. They answered a number of questions concerning their food and drink consumption that day and performed cognitive tests of attention and episodic memory. Children who had had breakfast showed superior performance on tests of attention and memory, confirming a previous laboratory based study using the same cognitive tests. This study adds weight to the growing body of literature indicating that breakfast plays a positive role in maintaining cognitive function during the morning.

The effect of high lactose-isomaltulose on cognitive performance of young children. A double blind cross-over design study.

Changes in blood glucose are hypothesized to influence cognitive performance and these changes can be affected by certain nutrients. This double-blind 4-period cross-over study evaluated the effects of a slow-release modified sucrose (isomaltulose) in combination with a high concentration of lactose on cognitive performance of 5-6 year old children. Thirty children received a standard growing upmilk (Std GUM), reformulated growing up milk (Reform GUM), standard growing up milk with lactose-isomaltulose (Iso GUM), and a standard glucose drink (Glucose). The CDR System, a computerised cognitive assessment system, was used to assess various measures of attention and memory of the children at baseline (T=0), 60 (T=1), 120 (T=2), and 180 (T=3) minutes following the intake of test products. Overall, there was a decline in performance over the morning on almost every cognitive task. Children showed better attention following consumption of Iso GUM compared to Std GUM but attention was not significantly different than Reform GUM and glucose. Also, Iso GUM conferred a beneficial effect over both Reform GUM and glucose on sensitivity index of numeric working memory with no difference observed between Iso GUM and Std GUM. Surprisingly, glucose group showed lowest decline in the sensitivity index of spatial working memory and highest speed in picture recognition, although the latter was significantly better than Reform GUM only. For speed of spatial working memory, Reform GUM had the lowest decline but was significantly different only with Std GUM. There was, however, no significant difference among conditions for continuity of attention, speed of numeric working memory and picture recognition sensitivity. Despite the small sample size, the findings are intriguing as carbohydrate composition seems to influence some aspects of cognitive performance such as attention and memory. However, further studies are needed to confirm these findings.

The Neurocognitive Effects of Bacopa monnieri and Cognitive Training on Markers of Brain Microstructure in Healthy Older Adults.

Bacopa monnieri (BM) is a herbal supplement that increases signaling molecules implicated in synaptogenesis. Combined with cognitive stimulation, it may be a viable supplement to enhance long-term potentiation (LTP) and improve cognitive health in older adults. This randomized, double-blind, placebo-controlled trial asked 28 healthy adults aged over 55 years to complete cognitive training (CT) 3 hours weekly for 12 weeks. Fifteen consumed a standardized extract of BM and 13 consumed a placebo daily. Cognitive tasks, life-satisfaction, memory complaints and mood were assessed, and bloods analyzed for serum brain-derived neurotrophic factor (BDNF) before and after 12-weeks of the intervention. Diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) in gray (GM) and white matter (WM) were also analyzed. Results demonstrated slower reaction time in an image discrimination task in the BM group and faster reaction time in a spatial working memory task (SWM-O RT) in the placebo group. Mean accuracy was higher in the BM group for these tasks, suggesting a change in the speed accuracy trade-off. Exploratory neuroimaging analysis showed increased WM mean diffusivity (MD) and GM dispersion of neurites (orientation dispersion index, ODI) and decreased WM fractional anisotropy (FA) and GM neurite density (ND) in the BM group. No other outcomes reached statistical significance. An increase in ODI with a decrease in MD and ND in the BM group may indicate an increase in network complexity (through higher dendritic branching) accompanied by dendritic pruning to enhance network efficiency. These neuroimaging outcomes conflict with the behavioral results, which showed poorer reaction time in the BM group. Given the exploratory outcomes and inconsistent findings between the behavioral and neuroimaging data, a larger study is needed to confirm the synaptogenic mechanisms of BM.

Differential effects of the aromas of Salvia species on memory and mood.

This study investigated the potential for the aromas of the essential oils of Salvia species to affect cognition and mood in healthy adults. Research has demonstrated that orally administered Salvia officinalis and Salvia lavandulaefolia are capable of modulating cognition and mood. The active compounds in the herbal products might also be present in the aromas and so produce similar effects. In an independent groups design, three conditions, S. officinalis aroma, S. lavandulaefolia aroma and no aroma were employed. One hundred and thirty-five healthy volunteers acted as participants, with 45 in each condition. Cognitive performance was assessed via the Cognitive Drug Research (CDR) System. Bond-Lader mood scales measured the participants' mood on three dimensions before and after the cognitive tasks. Data analysis revealed that the S. officinalis aroma group performed significantly better than the control group on the quality of memory and secondary memory primary outcome factors from the test battery. The Alert mood measure displayed significant differences between both aromas and the control condition. These findings suggest that the aromas of essential oils of Salvia species reproduce some but not all of the effects found following oral herb administration, and that interesting dissociations occur between subjective and objective responses.

Does a neuropsychological index of hemispheric lateralization predict onset of upper respiratory tract infectious symptoms?

OBJECTIVES: Past studies demonstrate relationships between hemispheric lateralization (HL) and immunity. However, the relevance of HL-immune relationships to health and illness has rarely been investigated. This study tested whether a neuropsychological index of right-hemispheric lateralization (right-HL) predicts development of upper respiratory tract infectious (URTI) symptoms. DESIGN: We used a prospective, matched, case-control design. METHODS: Initially, 80 URTI symptom free adults underwent neuropsychological assessment including right-HL (picture vs. word recognition), and were then followed-up during 10 weeks for development of URTI symptoms and objective signs of URTI. Participants reporting URTI symptoms (Ill; N=21) were matched on age, gender, and IQ with 21 participants remaining well. RESULTS: At baseline, the right-HL index was significantly higher in participants who later became ill (9.9%) compared to well participants (3.9%, p<.05). Health behaviour also predicted URTI symptoms. In a logistic regression, right-HL significantly predicted self-reported URTI, independent of health behaviour and neuroticism. CONCLUSIONS: Greater right-HL predicted URTI symptom development during follow-up, independent of important confounders. These findings expand previous HL-immune relationships to a common immune-related illness.

Cognitive profiles in obstructive sleep apnea: a cluster analysis in sleep clinic and community samples.

STUDY OBJECTIVES: Although cognitive dysfunction is a recognized consequence of untreated obstructive sleep apnea (OSA), the deficit pattern is heterogeneous. Understanding this heterogeneity may identify those at risk of cognitive deficits and guide intervention strategies. To facilitate understanding, we examined whether distinct profiles of neuropsychological performance were present in OSA and, if so, how they are related to other OSA features. METHODS: We studied sleep clinic (n = 121) and community (n = 398) samples with moderate-severe OSA (apnea-hypopnea index ≥ 15 events/h). Attention and memory were assessed using the Cognitive Drug Research system. Sleep was assessed using polysomnography in the clinic sample and dual channel (flow, oximetry) portable monitoring in the community sample. Latent profile analysis was used to determine structure of cognitive clusters. Discriminant function analysis was used to examine associations between nocturnal and diurnal features of OSA and profile membership. RESULTS: Both samples were best characterized by a 3-profile solution: (1) strong thinkers (performed well across most domains and showed greater cognitive reserve); (2) inattentive fast thinkers (strong processing speed but poor ability to maintain attention); and (3) accurate slow thinkers (strengths in maintaining attention but poor processing speed). Profile membership was associated with mean overnight oxygen saturation and cognitive reserve in the clinic sample and the presence of cardiovascular disease and/or diabetes in the community sample. CONCLUSIONS: These findings help explain the diversity of outcomes in previous studies of cognitive dysfunction in OSA by demonstrating that individual differences in cognitive reserve, nocturnal oxygen saturation, and comorbidities affect how cognition is impacted by OSA.

Effects of Purified Anthocyanins in People at Risk for Dementia: Study Protocol for a Phase II Randomized Controlled Trial.

Background: The number of people with dementia is increasing, with huge challenges for society and health-care systems. There are no disease-modifying therapies available. There is, therefore, an urgent need to identify strategies to reduce the risk of developing dementia. Anthocyanins are a class of compounds found in dark berries and fruits with some effects that might reduce the risk for cognitive decline and the development of dementia in older people. Aim: This phase II three-center, randomized, 24-week, placebo-controlled study, ongoing in Norway, aims to evaluate the safety, and efficacy of anthocyanins in modifying key dementia-related mechanisms and maintain cognitive functioning in older people at risk for dementia. Methods: Participants (220 individuals aged 60-80 years) who meet the inclusion criteria (either mild cognitive impairment or two or more cardiometabolic disorders) are being enrolled in this study at three different centers in Norway. Participants are block randomized to identically appearing capsules containing 80 mg of naturally purified anthocyanins or placebo 1:1. Dosage is 2 + 2 capsules per day for 24 weeks. The primary outcome will be the quality of episodic memory score, a composite measure from the extensively validated online cognitive test battery CogTrack®, which is administered at baseline and monthly for the next 6 months. Secondary outcomes include other major scores from CogTrack, as well as a range of neuroimaging and other biomarkers. Anthocyanin metabolites will be measured in blood and cerebrospinal fluid. The change from baseline scores will be subject to a mixed model for repeated measures analysis of covariance. The primary comparison will be the contrast (difference in the least-square means) between active and placebo at the end of the study (week 24). The primary study population will be a modified intention-to-treat population (ClinicalTrials.gov, NCT03419039). Discussion: This study aims to demonstrate whether there are beneficial effects of purified anthocyanins on cognition and relevant biological functions in people at increased risk for dementia. Forthcoming results may contribute to further improvement of intervention strategies to prevent or delay the onset of dementia, including a potential decision to take anthocyanins toward phase III trials.