Medicine and Health Sciences Commons^™

Cognitive And Neuroscientific Perspectives Of Healthy Ageing, Jon B. Prince, Helen L. Davis, Jane Tan, Katrina Muller-Townsend, Shaun Markovic, David M. G. Lewis, Brianne Hastie, Matthew B. Thompson, Peter D. Drummond, Hakuei Fujiyama, Hamid R. Sohrabi

Research outputs 2022 to 2026

With dementia incidence projected to escalate significantly within the next 25 years, the United Nations declared 2021–2030 the Decade of Healthy Ageing, emphasising cognition as a crucial element. As a leading discipline in cognition and ageing research, psychology is well-equipped to offer insights for translational research, clinical practice, and policy-making. In this comprehensive review, we discuss the current state of knowledge on age-related changes in cognition and psychological health. We discuss cognitive changes during ageing, including (a) heterogeneity in the rate, trajectory, and characteristics of decline experienced by older adults, (b) the role of cognitive reserve in age-related cognitive decline, …

Suboptimal Self-Reported Sleep Efficiency And Duration Are Associated With Faster Accumulation Of Brain Amyloid Beta In Cognitively Unimpaired Older Adults, Louise N. Pivac, Belinda M. Brown, Kelsey R. Sewell, James D. Doecke, Victor L. Villemagne, Vincent Doré, Michael Weinborn, Hamid R. Sohrabi, Samantha L. Gardener, Romola S. Bucks, Simon M. Laws, Kevin Taddei, Paul Maruff, Colin L. Masters, Christopher Rowe, Ralph N. Martins, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

INTRODUCTION: This study investigated whether self-reported sleep quality is associated with brain amyloid beta (AB) accumulation. METHODS: Linear mixed effect model analyses were conducted for 189 cognitively unimpaired (CU) older adults (mean ± standard deviation 74.0 ± 6.2; 53.2% female), with baseline self-reported sleep data, and positron emission tomography-determined brain AB measured over a minimum of three time points (range 33.3–72.7 months). Analyses included random slopes and intercepts, interaction for apolipoprotein E (APOE) 4 allele status, and time, adjusting for sex and baseline age. RESULTS: Sleep duration < 6 hours, in APOE 4 carriers, and sleep efficiency < 65%, in the whole sample and APOE 4 non-carriers, is associated with faster accumulation of brain AB. DISCUSSION: These findings suggest a role for self-reported suboptimal sleep efficiency and duration in the accumulation of Alzheimer's disease (AD) neuropathology in CU individuals. Additionally, poor sleep efficiency represents a potential route via which individuals at lower genetic risk may progress to preclinical AD. Highlights: In cognitively unimpaired older adults self-report sleep is associated with brain amyloid beta (AB) accumulation. Across sleep characteristics, this relationship differs by apolipoprotein E (APOE) genotype. Sleep duration < 6 hours is associated with faster brain AB accumulation in APOE 4 carriers. Sleep efficiency < 65% is associated with faster brain AB accumulation in APOE 4 non-carriers. Personalized sleep interventions should be studied for potential to slow AB accumulation.

The Australian Multidomain Approach To Reduce Dementia Risk By Protecting Brain Health With Lifestyle Intervention Study (Au-Arrow): A Study Protocol For A Single-Blind, Multi-Site, Randomized Controlled Trial, Samantha L. Gardener, Stephanie J. Fuller, Sharon L. Naismith, Laura Baker, Miia Kivipelto, Victor L. Villemagne, Stuart M. Grieve, Paul Yates, Stephanie R. Rainey-Smith, Juliana Chen, Belinda Thompson, Nicola J. Armstrong, Malika G. Fernando, Carolina B. Castro, Silochna Meghwar, Rema Raman, Andrew Gleason, Catriona Ireland, Roger Clarnette, Kaarin J. Anstey, Kevin Taddei, Manohar Garg, Hamid R. Sohrabi, Ralph N. Martins

Research outputs 2022 to 2026

INTRODUCTION: The Finnish Geriatric Intervention Study (FINGER) led to the global dementia risk reduction initiative: World-Wide FINGERS (WW-FINGERS). As part of WW-FINGERS, the Australian AU-ARROW study mirrors aspects of FINGER, as well as US-POINTER. METHOD: AU-ARROW is a randomized, single-blind, multisite, 2-year clinical trial (n = 600; aged 55–79). The multimodal lifestyle intervention group will engage in aerobic exercise, resistance training and stretching, dietary advice to encourage MIND diet adherence, BrainHQ cognitive training, and medical monitoring and health education. The Health Education and Coaching group will receive occasional health education sessions. The primary outcome measure is the change in a …

Investigating The Genetic Makeup Of The Major Histocompatibility Complex (Mhc) In The United Arab Emirates Population Through Next-Generation Sequencing, Nour A. D. Marzouka, Halima Alnaqbi, Amira Al-Aamri, Guan Tay, Habiba Alsafar

Research outputs 2022 to 2026

The Human leukocyte antigen (HLA) molecules are central to immune response and have associations with the phenotypes of various diseases and induced drug toxicity. Further, the role of HLA molecules in presenting antigens significantly affects the transplantation outcome. The objective of this study was to examine the extent of the diversity of HLA alleles in the population of the United Arab Emirates (UAE) using Next-Generation Sequencing methodologies and encompassing a larger cohort of individuals. A cohort of 570 unrelated healthy citizens of the UAE volunteered to provide samples for Whole Genome Sequencing and Whole Exome Sequencing. The definition of the …

The Role Of Diet And Gut Microbiota In Alzheimer’S Disease, D. M.Sithara Dissanayaka, Vijay Jayasena, Stephanie R. Rainey-Smith, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Alzheimer’s disease (AD), the most prevalent form of dementia, is characterized by the accumulation of amyloid-beta (A ) plaques and hyperphosphorylated tau tangles. Currently, Alzheimer’s disease (AD) impacts 50 million individuals, with projections anticipating an increase to 152 million by the year 2050. Despite the increasing global prevalence of AD, its underlying pathology remains poorly understood, posing challenges for early diagnosis and treatment. Recent research suggests a link between gut dysbiosis and the aggregation of A , the development of tau proteins, and the occurrence of neuroinflammation and oxidative stress are associated with AD. However, investigations into the gut–brain axis …

Changes In Sleep Effort Mediate Insomnia Severity In Older Adults Following Online Cognitive Behavioural Therapy, Yvonne Kutzer, Lisa Whitehead, Eimear Quigley, Mandy Stanley

Research outputs 2022 to 2026

Background

To examine treatment mechanisms of digitally delivered cognitive behavioural therapy for insomnia (CBT-I), this study assessed the mediating effects of dysfunctional beliefs, hyperarousal, locus of control, self-efficacy, sleep effort, and safety behaviours on self-reported insomnia severity in older adults before and following the completion of a self-guided, online CBT-I program.

Methods

The baseline and follow-up measurements were completed by 62 older adults (55 female, 89%). This was a two-condition within-participant design. Mediation analysis using a parallel mediation model was conducted using the MEMORE macro for repeated measure designs.

Results

Out of all the included mediator variables, only a reduction …

Editorial: Neurotoxins In Alzheimer's Disease And Other Dementias, Alexandre Henriques, Philippe L. L. Poindron, Binosha Fernando, Kevin N. Hascup

Research outputs 2022 to 2026

Alzheimer's disease (AD) and other dementias are neurodegenerative disorders characterized by a progressive decline in cognition and independence from activities of daily living. Dementia is multifactorial with numerous risk factors including age, genes, molecules, lifestyle, and environmental contributions to disease onset and progression. In recent years, an emerging focus on neurotoxins has added a new layer of complexity to our understanding of dementia. This editorial aims to discuss recent updates regarding the role of neurotoxins in the pathogenesis of dementia.

Fluid Biomarkers In Cerebral Amyloid Angiopathy, Seyed M. Savar, Bin Ma, Eugene Hone, Farzana Jahan, Shaun Markovic, Steve Pedrini, Soudabeh Shemehsavar, Vandhana Easwaran, Kevin Taddei, Samantha Gardener, Jasmeer P. Chhatwal, Ellis S. Van Etten, Matthias J. P. Van Osch, Daniel Clarke, Anastazija Gnjec, Mark A. Van Buchem, Marieke J. H. Wermer, Graeme J. Hankey, Steven M. Greenberg, Ralph N. Martins, Hamid R. Sohrabi

Research outputs 2022 to 2026

Cerebral amyloid angiopathy (CAA) is a type of cerebrovascular disorder characterised by the accumulation of amyloid within the leptomeninges and small/medium-sized cerebral blood vessels. Typically, cerebral haemorrhages are one of the first clinical manifestations of CAA, posing a considerable challenge to the timely diagnosis of CAA as the bleedings only occur during the later disease stages. Fluid biomarkers may change prior to imaging biomarkers, and therefore, they could be the future of CAA diagnosis. Additionally, they can be used as primary outcome markers in prospective clinical trials. Among fluid biomarkers, blood-based biomarkers offer a distinct advantage over cerebrospinal fluid biomarkers …

Excitatory Drive To Spinal Motoneurones Is Necessary For Serotonin To Modulate Motoneurone Excitability Via 5-Ht2 Receptors In Humans, Tyler T. Henderson, Janet L. Taylor, Jacob R. Thorstensen, Justin J. Kavanagh

Research outputs 2022 to 2026

Serotonin modulates corticospinal excitability, motoneurone firing rates and contractile strength via 5-HT2 receptors. However, the effects of these receptors on cortical and motoneurone excitability during voluntary contractions have not been explored in humans. Therefore, the purpose of this study was to investigate how 5-HT2 antagonism affects corticospinal and motoneuronal excitability with and without descending drive to motoneurones. Twelve individuals (aged 24 ± 4 years) participated in a double-blind, placebo-controlled, crossover study, whereby the 5-HT2 antagonist cyproheptadine was administered. Transcranial magnetic stimulation (TMS) was delivered to the motor cortex to produce motor evoked potentials (MEPs), and electrical stimulation at the cervicomedullary …

Predicting Neurodegeneration From Sleep Related Biofluid Changes, Yue Yang, Woojin S. Kim, Johannes C. Michaelian, Simon J. G. Lewis, Craig L. Phillips, Angela L. D'Rozario, Pratishtha Chatterjee, Ralph N. Martins, Ron Grunstein, Glenda M. Halliday, Sharon L. Naismith

Research outputs 2022 to 2026

Sleep-wake disturbances are common in neurodegenerative diseases and may occur years before the clinical diagnosis, potentially either representing an early stage of the disease itself or acting as a pathophysiological driver. Therefore, discovering biomarkers that identify individuals with sleep-wake disturbances who are at risk of developing neurodegenerative diseases will allow early diagnosis and intervention. Given the association between sleep and neurodegeneration, the most frequently analyzed fluid biomarkers in people with sleep-wake disturbances to date include those directly associated with neurodegeneration itself, such as neurofilament light chain, phosphorylated tau, amyloid-beta and alpha-synuclein. Abnormalities in these biomarkers in patients with sleep-wake disturbances …

Unveiling The Link Between Systemic Inflammation Markers And Cognitive Performance Among Older Adults In The Us: A Population-Based Study Using Nhanes 2011–2014 Data, Zheng Guo, Yulu Zheng, Jian Geng, Zhiyuan Wu, Tao Wei, Guangle Shan, Yahong Zhu, Yuanyuan Zheng, Xingang Li

Research outputs 2022 to 2026

Purpose: This study aimed to evaluate the association between systemic inflammation markers and cognitive performance among older US adults. Methods: This cross-sectional study assessed 3,632 older participants from the 2011–2014 National Health and Nutrition Examination Survey (NHANES). The main analysis included participants aged over 60 years. Systemic inflammation markers were quantified by calculating the composite inflammation indicators from the blood routine count, and cognitive performance was assessed using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, Animal Fluency test (AFT), and Digit Symbol Substitution test (DSST). Results: There were 2,743 individuals enrolled in the current analysis. The overall …

Neuropsychiatric Symptoms Of Dementia In Those With And Without A Recorded History Of Psychological Trauma: A Comparative Study From An Australian Dementia Support Service, Monica Cations, Mustafa Atee, Thomas Morris, Daniel Whiting

Research outputs 2022 to 2026

Objective: To compare the number and severity of neuropsychiatric symptoms (NPS) and associated caregiver distress between those with and without a noted history of psychological trauma among those referred to a specialised national dementia NPS support service. Methods: This was a 5-year retrospective observational study of records from the Dementia Support Australia NPS support service. NPS were reported by formal or informal caregivers at service entry using the Neuropsychiatric Inventory Nursing Home version or Questionnaire version. A history of psychological trauma was recorded in the person's social or medical history and/or endorsed as a contributor to NPS by a trained …

The Association Between Plasma Igg N-Glycosylation And Neonatal Hypoxic–Ischemic Encephalopathy: A Case-Control Study, Liangao Wang, Xinxia Lu, Meng Wang, Xuezhen Zhao, Peirui Li, Haitao Zhang, Qingtang Meng, Yujing Zhang, Yingjie Wang, Wei Wang, Long Ji, Haifeng Hou, Dong Li

Research outputs 2022 to 2026

Introduction: Hypoxic-ischemic encephalopathy (HIE) is one of severe neonatal brain injuries, resulting from inflammation and the immune response after perinatal hypoxia and ischemia. IgG N-glycosylation plays a crucial role in various inflammatory diseases through mediating the balance between anti-inflammatory and pro-inflammatory responses. This study aimed to explore the effect of IgG N-glycosylation on the development of HIE. Methods: This case-control study included 53 HIE patients and 57 control neonates. An ultrahigh-performance liquid chromatography (UPLC) method was used to determine the features of the plasma IgG N-glycans, by which 24 initial glycan peaks (GPs) were quantified. Multivariate logistic regression was used …

A Systematic Review Of Dementia Research Priorities, Manonita Ghosh, Pelden Chejor, Melanie Baker, Davina Porock

Research outputs 2022 to 2026

Introduction: Patient involvement is a critical component of dementia research priority-setting exercises to ensure that research benefits are relevant and acceptable to those who need the most. This systematic review synthesises research priorities and preferences identified by people living with dementia and their caregivers. Methods: Guided by Joanna Briggs Institute methodology, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework, we conducted a systematic search in five electronic databases: CINAHL, Medline, PsycINFO, Web of Science and Scopus. The reference lists of the included studies were also manually searched. We combined quantitative and qualitative data for synthesis and descriptive thematic …