Differences in trajectories of quality of life according to type of dementia: 6-year longitudinal findings from the IDEAL programme.

BACKGROUND: People with different types of dementia may have distinct symptoms and experiences that affect their quality of life. This study investigated whether quality of life varied across types of dementia and over time. METHODS: The participants were 1555 people with mild-to-moderate dementia and 1327 carers from the IDEAL longitudinal cohort study, recruited from clinical services. As many as possible were followed for up to 6 years. Diagnoses included were Alzheimer's disease, vascular dementia, mixed Alzheimer's and vascular dementia, Parkinson's disease dementia, dementia with Lewy bodies, and frontotemporal dementia. Self- and informant-rated versions of the Quality of Life in Alzheimer's Disease scale were used. A joint model, incorporating a mixed effects model with random effects and a survival model to account for dropout, was used to examine whether quality of life varied by dementia type at the time of diagnosis and how trajectories changed over time. RESULTS: The strongest associations between dementia type and quality of life were seen around the time of diagnosis. For both self-ratings and informant ratings, people with Parkinson's disease dementia or dementia with Lewy bodies had lower quality of life scores. Over time there was little change in self-rated scores across all dementia types (- 0.15 points per year). Informant-rated scores declined over time (- 1.63 points per year), with the greatest decline seen in ratings by informants for people with dementia with Lewy bodies (- 2.18 points per year). CONCLUSIONS: Self-rated quality of life scores were relatively stable over time whilst informant ratings showed a steeper decline. People with Parkinson's disease dementia or dementia with Lewy bodies report particularly low levels of quality of life, indicating the importance of greater attention to the needs of these groups.

Associations between multimorbidity and neuropathology in dementia: consideration of functional cognitive disorders, psychiatric illness and dementia mimics.

BACKGROUND: Multimorbidity, the presence of two or more health conditions, has been identified as a possible risk factor for clinical dementia. It is unclear whether this is due to worsening brain health and underlying neuropathology, or other factors. In some cases, conditions may reflect the same disease process as dementia (e.g. Parkinson's disease, vascular disease), in others, conditions may reflect a prodromal stage of dementia (e.g. depression, anxiety and psychosis). AIMS: To assess whether multimorbidity in later life was associated with more severe dementia-related neuropathology at autopsy. METHOD: We examined ante-mortem and autopsy data from 767 brain tissue donors from the UK, identifying physical multimorbidity in later life and specific brain-related conditions. We assessed associations between these purported risk factors and dementia-related neuropathological changes at autopsy (Alzheimer's-disease related neuropathology, Lewy body pathology, cerebrovascular disease and limbic-predominant age-related TDP-43 encephalopathy) with logistic models. RESULTS: Physical multimorbidity was not associated with greater dementia-related neuropathological changes. In the presence of physical multimorbidity, clinical dementia was less likely to be associated with Alzheimer's disease pathology. Conversely, conditions which may be clinical or prodromal manifestations of dementia-related neuropathology (Parkinson's disease, cerebrovascular disease, depression and other psychiatric conditions) were associated with dementia and neuropathological changes. CONCLUSIONS: Physical multimorbidity alone is not associated with greater dementia-related neuropathological change; inappropriate inclusion of brain-related conditions in multimorbidity measures and misdiagnosis of neurodegenerative dementia may better explain increased rates of clinical dementia in multimorbidity.

Living Alone With Mild-to-Moderate Dementia Over a Two-Year Period: Longitudinal Findings From the IDEAL Cohort.

OBJECTIVES: To compare the experiences of people with dementia living alone or with others and how these may change over two years. DESIGN: We analysed longitudinal data from three assessment waves, one year apart, in the British IDEAL cohort. SETTING: Participants with mild-to-moderate dementia were recruited through National Health Service providers, where possible with a family caregiver, and interviewed at home. PARTICIPANTS: The current analyses include 281 people with dementia living alone and 1,244 living with others at baseline; follow-up data were available for 200 and 965 respectively at time 2 and 144 and 696 respectively at time 3. For those living alone, 140 nonresident caregivers contributed at baseline, 102 at time 2 and 81 at time 3. For those living with others, 1,127 family caregivers contributed at baseline, 876 at time 2 and 670 at time 3. MEASUREMENTS: Assessments covered: cognitive and functional ability; self-reported perceptions of health, mood, social engagement, quality of life, satisfaction with life and well-being; use of in-home and community care; and transitions into residential care. RESULTS: People living alone tended to have better cognitive and functional ability and were more frequent users of in-home care. However, they experienced poorer physical, social, and psychological health and reduced quality of life, satisfaction with life, and well-being. These differences persisted over time and rates of transition into residential care were higher. CONCLUSIONS: To facilitate continuing in place for people with dementia living alone, a dual focus on supporting functional ability and addressing psychosocial needs is essential in the context of an enabling policy framework.

Living well with dementia: An exploratory matched analysis of minority ethnic and white people with dementia and carers participating in the IDEAL programme.

OBJECTIVES: The increasing heterogeneity of the population of older people is reflected in an increasing number of people with dementia and carers drawn from minority ethnic groups. Data from the IDEAL study are used to compare indices of 'living well' among people with dementia and carers from ethnic minority groups with matched white peers. METHODS: We used an exploratory cross-sectional case-control design to compare 'living well' for people with dementia and carers from minority ethnic and white groups. Measures for both groups were quality of life, life satisfaction, wellbeing, loneliness, and social isolation and, for carers, stress, relationship quality, role captivity and caring competence. RESULTS: The sample of people with dementia consisted of 20 minority ethnic and 60 white participants and for carers 15 and 45 respectively. People with dementia from minority ethnic groups had poorer quality of life (-4.74, 95% CI: -7.98 to -1.50) and higher loneliness (1.72, 95% CI: 0.78-2.66) whilst minority ethnic carers had higher stress (8.17, 95% CI: 1.72-14.63) and role captivity (2.00, 95% CI: 0.43-3.57) and lower relationship quality (-9.86, 95% CI: -14.24 to -5.48) than their white peers. CONCLUSION: Our exploratory study suggests that people with dementia from minority ethnic groups experience lower quality of life and carers experience higher stress and role captivity and lower relationship quality than their white peers. Confirmatory research with larger samples is required to facilitate analysis of the experiences of specific minority ethnic groups and examine the factors contributing to these disadvantages.

Health conditions in spousal caregivers of people with dementia and their relationships with stress, caregiving experiences, and social networks: longitudinal findings from the IDEAL programme.

OBJECTIVES: Longitudinal evidence documenting health conditions in spousal caregivers of people with dementia and whether these influence caregivers' outcomes is scarce. This study explores type and number of health conditions over two years in caregivers of people with dementia and subgroups based on age, sex, education, hours of care, informant-rated functional ability, neuropsychiatric symptoms, cognition of the person with dementia, and length of diagnosis in the person with dementia. It also explores whether over time the number of health conditions is associated with caregivers' stress, positive experiences of caregiving, and social networks METHODS: Longitudinal data from the IDEAL (Improving the experience of Dementia and Enhancing Active Life) cohort were used. Participants comprised spousal caregivers (n = 977) of people with dementia. Self-reported health conditions using the Charlson Comorbidity Index, stress, positive experiences of caregiving, and social network were assessed over two years. Mixed effect models were used RESULTS: On average participants had 1.5 health conditions at baseline; increasing to 2.1 conditions over two years. More health conditions were reported by caregivers who were older, had no formal education, provided 10 + hours of care per day, and/or cared for a person with more neuropsychiatric symptoms at baseline. More baseline health conditions were associated with greater stress at baseline but not with stress over time. Over two years, when caregivers' health conditions increased, their stress increased whereas their social network diminished DISCUSSION: Findings highlight that most caregivers have their own health problems which require management to avoid increased stress and shrinking of social networks.

Comorbid health conditions and their impact on social isolation, loneliness, quality of life, and well-being in people with dementia: longitudinal findings from the IDEAL programme.

BACKGROUND: Most people with dementia have multiple health conditions. This study explores (1) number and type of health condition(s) in people with dementia overall and in relation to age, sex, dementia type, and cognition; (2) change in number of health conditions over two years; and (3) whether over time the number of health conditions at baseline is related to social isolation, loneliness, quality of life, and/or well-being. METHODS: Longitudinal data from the IDEAL (Improving the experience of Dementia and Enhancing Active Life) cohort were used. Participants comprised people with dementia (n = 1490) living in the community (at baseline) in Great Britain. Health conditions using the Charlson Comorbidity Index, cognition, social isolation, loneliness, quality of life, and well-being were assessed over two years. Mixed effects modelling was used. RESULTS: On average participants had 1.8 health conditions at baseline, excluding dementia; increasing to 2.5 conditions over two years. Those with vascular dementia or mixed (Alzheimer's and vascular) dementia had more health conditions than those with Alzheimer's disease. People aged ≥ 80 had more health conditions than those aged < 65 years. At baseline having more health conditions was associated with increased loneliness, poorer quality of life, and poorer well-being, but was either minimally or not associated with cognition, sex, and social isolation. Number of health conditions had either minimal or no influence on these variables over time. CONCLUSIONS: People with dementia in IDEAL generally had multiple health conditions and those with more health conditions were lonelier, had poorer quality of life, and poorer well-being.

Identifying predictors of transition to a care home for people with dementia: findings from the IDEAL programme.

OBJECTIVES: This study investigates factors associated with the person with dementia and the caregiver to identify those associated with an increased risk of transition to a care home. METHOD: IDEAL data were collected at baseline and at 12- and 24-month follow-up for 1545 people with dementia and 1305 caregivers. Modified Poisson regressions with an offset for 'person years at risk' were used. Person with dementia factors explored were personal characteristics, cognition, health, self- and informant-rated functional ability, and neuropsychiatric symptoms. Caregiver factors explored were personal characteristics, stress, health, and quality of the dyadic relationship. RESULTS: A 5% people moved into care. Risk of moving into a care home was higher among people with dementia who were ≥80 years, among people with Parkinson's disease dementia or dementia with Lewy bodies, and among those without a spousal caregiver. Poorer cognition and more self-rated or informant-rated functional difficulties increased the risk of moving into care. CONCLUSION: Factors related to increased dementia severity and greater disability are the primary influences that place people with dementia at greater risk of moving into a care home. Strategies that help to maintain everyday functional ability for people with dementia could help delay people with dementia moving into care.

The Microglial Transcriptome of Age-Associated Deep Subcortical White Matter Lesions Suggests a Neuroprotective Response to Blood-Brain Barrier Dysfunction.

Age-associated deep-subcortical white matter lesions (DSCLs) are an independent risk factor for dementia, displaying high levels of CD68+ microglia. This study aimed to characterize the transcriptomic profile of microglia in DSCLs and surrounding radiologically normal-appearing white matter (NAWM) compared to non-lesional control white matter. CD68+ microglia were isolated from white matter groups (n = 4 cases per group) from the Cognitive Function and Ageing Study neuropathology cohort using immuno-laser capture microdissection. Microarray gene expression profiling, but not RNA-sequencing, was found to be compatible with immuno-LCM-ed post-mortem material in the CFAS cohort and identified significantly differentially expressed genes (DEGs). Functional grouping and pathway analysis were assessed using the Database for Annotation Visualization and Integrated Discovery (DAVID) software, and immunohistochemistry was performed to validate gene expression changes at the protein level. Transcriptomic profiling of microglia in DSCLs compared to non-lesional control white matter identified 181 significant DEGs (93 upregulated and 88 downregulated). Functional clustering analysis in DAVID revealed dysregulation of haptoglobin-haemoglobin binding (Enrichment score 2.5, p = 0.017), confirmed using CD163 immunostaining, suggesting a neuroprotective microglial response to blood-brain barrier dysfunction in DSCLs. In NAWM versus control white matter, microglia exhibited 347 DEGs (209 upregulated, 138 downregulated), with significant dysregulation of protein de-ubiquitination (Enrichment score 5.14, p < 0.001), implying an inability to maintain protein homeostasis in NAWM that may contribute to lesion spread. These findings enhance understanding of microglial transcriptomic changes in ageing white matter pathology, highlighting a neuroprotective adaptation in DSCLs microglia and a potentially lesion-promoting phenotype in NAWM microglia.

Relationships of brain cholesterol and cholesterol biosynthetic enzymes to Alzheimer's pathology and dementia in the CFAS population-derived neuropathology cohort.

Altered cholesterol metabolism is implicated in brain ageing and Alzheimer's disease. We examined whether key genes regulating cholesterol metabolism and levels of brain cholesterol are altered in dementia and Alzheimer's disease neuropathological change (ADNC). Temporal cortex (n = 99) was obtained from the Cognitive Function and Ageing Study. Expression of the cholesterol biosynthesis rate-limiting enzyme HMG-CoA reductase (HMGCR) and its regulator, SREBP2, were detected using immunohistochemistry. Expression of HMGCR, SREBP2, CYP46A1 and ABCA1 were quantified by qPCR in samples enriched for astrocyte and neuronal RNA following laser-capture microdissection. Total cortical cholesterol was measured using the Amplex Red assay. HMGCR and SREBP2 proteins were predominantly expressed in pyramidal neurones, and in glia. Neuronal HMGCR did not vary with ADNC, oxidative stress, neuroinflammation or dementia status. Expression of HMGCR neuronal mRNA decreased with ADNC (p = 0.022) and increased with neuronal DNA damage (p = 0.049), whilst SREBP2 increased with ADNC (p = 0.005). High or moderate tertiles for cholesterol levels were associated with increased dementia risk (OR 1.44, 1.58). APOE ε4 allele was not associated with cortical cholesterol levels. ADNC is associated with gene expression changes that may impair cholesterol biosynthesis in neurones but not astrocytes, whilst levels of cortical cholesterol show a weak relationship to dementia status.

Changes in prevalence and incidence of dementia and risk factors for dementia: an analysis from cohort studies.

BACKGROUND: Some cohort studies have reported a decline in dementia prevalence and incidence over time, although these findings have not been consistent across studies. We reviewed evidence on changes in dementia prevalence and incidence over time using published population-based cohort studies that had used consistent methods with each wave and aimed to quantify associated changes in risk factors over time using population attributable fractions (PAFs). METHODS: We searched for systematic reviews of cohort studies examining changes in dementia prevalence or incidence over time. We searched PubMed for publications from database inception up to Jan 12, 2023, using the search terms "systematic review" AND "dementia" AND ("prevalence" OR "incidence"), with no language restrictions. We repeated this search on March 28, 2024. From eligible systematic reviews, we searched the references and selected peer-reviewed publications about cohort studies where dementia prevalence or incidence was measured in the same geographical location, at a minimum of two timepoints, and that reported age-standardised prevalence or incidence of dementia. Additionally, data had to be from population-based samples, in which participants' cognitive status was assessed and where validated criteria were used to diagnose dementia. We extracted summary-level data from each paper about dementia risk factors, contacting authors when such data were not available in the published paper, and calculated PAFs for each risk factor at all available timepoints. Where possible, we linked changes in dementia prevalence or incidence with changes in the prevalence of risk factors. FINDINGS: We identified 1925 records in our initial search, of which five eligible systematic reviews were identified. Within these systematic reviews, we identified 71 potentially eligible primary papers, of which 27 were included in our analysis. 13 (48%) of 27 primary papers reported change in prevalence of dementia, ten (37%) reported change in incidence of dementia, and four (15%) reported change in both incidence and prevalence of dementia. Studies reporting change in dementia incidence over time in Europe (n=5) and the USA (n=5) consistently reported a declining incidence in dementia. One study from Japan reported an increase in dementia prevalence and incidence and a stable incidence was reported in one study from Nigeria. Overall, across studies, the PAFs for less education or smoking, or both, generally declined over time, whereas PAFs for obesity, hypertension, and diabetes generally increased. The decrease in PAFs for less education and smoking was associated with a decline in the incidence of dementia in the Framingham study (Framingham, MA, USA, 1997-2013), the only study with sufficient data to allow analysis. INTERPRETATION: Our findings suggest that lifestyle interventions such as compulsory education and reducing rates of smoking through country-level policy changes could be associated with an observed reduction, and therefore future reduction, in the incidence of dementia. More studies are needed in low-income and middle-income countries, where the burden of dementia is highest, and continues to increase. FUNDING: National Institute for Health and Care Research Three Schools' Dementia Research Programme.