Blood biomarkers of Alzheimer's disease in the community: Variation by chronic diseases and inflammatory status.

INTRODUCTION: We explored the variations of blood biomarkers of Alzheimer's disease (AD) by chronic diseases and systemic inflammation. METHODS: We explored the association of AD blood biomarkers with chronic diseases and systemic inflammation (interleukin-6 [IL-6]), in 2366 dementia-free participants of the Swedish National Study on Aging and Care-in Kungsholmen, using quantile regression models. RESULTS: A greater number of co-occurring chronic diseases was associated with higher concentrations of phosphorylated-tau 181 (p-tau181), total-tau (t-tau), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) (p < 0.01). Anemia, kidney, cerebrovascular, and heart diseases were associated with variations in the levels of AD blood biomarkers. Participants in the highest (vs. lowest) interleukin-6 (IL-6) tertile had higher NfL concentration. Systemic inflammation amplified the associations between several chronic diseases and p-tau181, t-tau, NfL, and GFAP. DISCUSSION: In the community, the concentration of AD blood biomarkers varies in relation to medical conditions and systemic inflammation. Recognizing these influences is crucial for the accurate interpretation and clinical implementation of blood biomarkers. HIGHLIGHTS: Participants with a complex clinical profile (i.e., multiple co-occurring diseases or specific disease combinations) display elevated levels of AD blood-biomarkers. Anemia, heart, cerebrovascular, and kidney diseases are associated with variations is the levels of AD blood biomarkers in cognitively intact older adults. Systemic inflammation amplifies the association between several chronic diseases and AD blood biomarkers.

Applicability of STOPP/START prescribing criteria in integrated Swedish administrative health registries and a Swedish population-based cohort.

PURPOSE: The STOPP/START criteria are frequently applied in observational studies to assess potentially inappropriate prescribing in older adults. This study aimed to assess the applicability of the three available STOPP/START versions in two distinct data sources. METHODS: To evaluate the applicability of the three versions of STOPP/START criteria, we used two observational data sources: (i) Integrated Swedish administrative health registries (ISHR) encompassing routinely collected health data and (ii) the population-based Swedish National study on Aging and Care in Kungsholmen (SNAC-K), based on health professional-led clinical assessments. The Anatomical Therapeutic Classification code (ATC) was used to categorise medications. Diseases were categorised using the international classification of diseases version 10 (ICD10). RESULTS: The first STOPP/START version demonstrated an applicability rate of 80% in ISHR and 84% in SNAC-K. The second version demonstrated an applicability of 64% in ISHR and 74% in SNAC-K. The third version showed an applicability of 66% in ISHR and 77% in SNAC-K. Challenges in applicability included broad definitions, vague terminology, and the lack of information on disease severity, symptomatic traits, and stability of certain conditions. CONCLUSION: The applicability of the STOPP/START criteria in observational studies seems to have decreased in more recent versions of the tool. Population-based studies with comprehensive clinical assessments may offer higher applicability compared to studies based on administrative data. Future versions of the STOPP/START criteria should prioritise clear and unambiguous definitions to improve their applicability in research and promote result generalisability and comparability.

Effectiveness of integrated person-centered interventions for older people's care: Review of Swedish experiences and experts' perspective.

Older adults have multiple medical and social care needs, requiring a shift toward an integrated person-centered model of care. Our objective was to describe and summarize Swedish experiences of integrated person-centered care by reviewing studies published between 2000 and 2023, and to identify the main challenges and scientific gaps through expert discussions. Seventy-three publications were identified by searching MEDLINE and contacting experts. Interventions were categorized using two World Health Organization frameworks: (1) Integrated Care for Older People (ICOPE), and (2) Integrated People-Centered Health Services (IPCHS). The included 73 publications were derived from 31 unique and heterogeneous interventions pertaining mainly to the micro- and meso-levels. Among publications measuring mortality, 15% were effective. Subjective health outcomes showed improvement in 24% of publications, morbidity outcomes in 42%, disability outcomes in 48%, and service utilization outcomes in 58%. Workshop discussions in Stockholm (Sweden), March 2023, were recorded, transcribed, and summarized. Experts emphasized: (1) lack of rigorous evaluation methods, (2) need for participatory designs, (3) scarcity of macro-level interventions, and (4) importance of transitioning from person- to people-centered integrated care. These challenges could explain the unexpected weak beneficial effects of the interventions on health outcomes, whereas service utilization outcomes were more positively impacted. Finally, we derived a list of recommendations, including the need to engage care organizations in interventions from their inception and to leverage researchers' scientific expertise. Although this review provides a comprehensive snapshot of interventions in the context of Sweden, the findings offer transferable perspectives on the real-world challenges encountered in this field.

Cardiometabolic disease, cognitive decline, and brain structure in middle and older age.

INTRODUCTION: The presence of multiple cardiometabolic diseases (CMDs) has been linked to increased dementia risk, but the combined influence of CMDs on cognition and brain structure across the life course is unclear. METHODS: In the UK Biobank, 46,562 dementia-free participants completed a cognitive test battery at baseline and a follow-up visit 9 years later, at which point 39,306 also underwent brain magnetic resonance imaging. CMDs (diabetes, heart disease, and stroke) were ascertained from medical records. Data were analyzed using age-stratified (middle age [< 60] versus older [≥ 60]) mixed-effects models and linear regression. RESULTS: A higher number of CMDs was associated with significantly steeper global cognitive decline in older (ß = -0.008; 95% confidence interval: -0.012, -0.005) but not middle age. Additionally, the presence of multiple CMDs was related to smaller total brain volume, gray matter volume, white matter volume, and hippocampal volume and larger white matter hyperintensity volume, even in middle age. DISCUSSION: CMDs are associated with cognitive decline in older age and poorer brain structural health beginning already in middle age. Highlights: We explored the association of CMDs with cognitive decline and brain MRI measures.CMDs accelerated cognitive decline in older (≥60y) but not middle (<60) age.CMDs were associated with poorer brain MRI parameters in both middle and older age.Results highlight the connection between CMDs and cognitive/brain aging.

Enhancing routine immunization efforts for older adults and frail individuals: Good practices during the SARS-CoV-2 pandemic in Italy.

Infectious diseases pose a significant burden on the general population, particularly older adults who are more susceptible to severe complications. Immunization plays a crucial role in preventing infections and securing a healthier aging, but actual vaccination rates among older adults and frail individuals (OAFs) remains far from recommended targets. This study aims to collect and share good practices implemented in several Italian local health districts during the SARS-CoV-2 pandemic to ease routine immunization for OAFs. A 28-items questionnaire has been developed to collect information on organization aspect of immunization services and local good practices implemented before and during the SARS-CoV-2 pandemic. Twelve Public Health managers representative of 9 Italian Regions were further interviewed between January and March 2021. Despite literature suggests several effective interventions to increase vaccine demand, improve vaccine access, and enhance healthcare providers' performance, our survey highlighted substantial heterogeneity in their implementation at local level. Seven good local practices have been identified and described: mass vaccination centers; vaccination mobile units; drive-through vaccination; co-administration; tailored pathways; cooperation among providers involved in vaccination; digitization. Our survey pointed out valuable strategies for enhancing routine immunization for OAFs. Providers should combine effective interventions adequate to their specific context and share good practices.

How to support general practitioners to better detect sarcopenia among older adults: a nested case-control analysis.

PURPOSE: This study explores correlations of sarcopenia and its proxies, such as history of falls, asthenia, and ambulation issues, with frailty levels among older adults in primary care. METHODS: In a cohort of 546,590 patients aged 60 years or older, "definite" sarcopenia cases were operationally defined through the use of non-specific diagnostic codes coupled with inspection of free-texts. Proxies of sarcopenia, such as falls history, asthenia, and ambulation issues were considered as well. Frailty was calculated using an Index intended to primary care. RESULTS: Overall, 171 definite sarcopenia cases were found, rising to 51,520 cases when including proxies (9.4% prevalence). There was a significant association between severe frailty and increased odds of sarcopenia, consistently observed across different event definitions. CONCLUSIONS: Sarcopenia was strongly associated with severe frailty in primary care. The history of falls, asthenia, and ambulation issues were reliable proxies to raise the suspect of sarcopenia. Improved strategies for sarcopenia detection, focusing on specific indicators within severely frail individuals, are warranted.

Somatic disease burden and depression risk in late life: a community-based study.

AIMS: Co-occurring somatic diseases exhibit complex clinical profiles, which can differentially impact the development of late-life depression. Within a community-based cohort, we aimed to explore the association between somatic disease burden, both in terms of the number of diseases and their patterns, and the incidence of depression in older people. METHODS: We analysed longitudinal data of depression- and dementia-free individuals aged 60+ years from the population-based Swedish National Study on Aging and Care in Kungsholmen. Depression diagnoses were clinically ascertained following the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision over a 15-year follow-up. Somatic disease burden was assessed at baseline through a comprehensive list of chronic diseases obtained by combining information from clinical examinations, medication reviews and national registers and operationalized as (i) disease count and (ii) patterns of co-occurring diseases from latent class analysis. The association of somatic disease burden with depression incidence was investigated using Cox models, accounting for sociodemographic, lifestyle and clinical factors. RESULTS: The analytical sample comprised 2904 people (mean age, 73.2 [standard deviation (SD), 10.5]; female, 63.1%). Over the follow-up (mean length, 9.6 years [SD, 4 years]), 225 depression cases were detected. Each additional disease was associated with the occurrence of any depression in a dose-response manner (hazard ratio [HR], 1.16; 95% confidence interval [CI]: 1.08, 1.24). As for disease patterns, individuals presenting with sensory/anaemia (HR, 1.91; 95% CI: 1.03, 3.53), thyroid/musculoskeletal (HR, 1.90; 95% CI: 1.06, 3.39) and cardiometabolic (HR, 2.77; 95% CI: 1.40, 5.46) patterns exhibited with higher depression hazards, compared to those without 2+ diseases (multimorbidity). In the subsample of multimorbid individuals (85%), only the cardiometabolic pattern remained associated with a higher depression hazard compared to the unspecific pattern (HR, 1.71; 95% CI: 1.02, 2.84). CONCLUSIONS: Both number and patterns of co-occurring somatic diseases are associated with an increased risk of late-life depression. Mental health should be closely monitored among older adults with high somatic burden, especially if affected by cardiometabolic multimorbidity.

Association of mild and complex multimorbidity with structural brain changes in older adults: A population-based study.

INTRODUCTION: We quantified the association of mild (ie, involving one or two body systems) and complex (ie, involving ≥3 systems) multimorbidity with structural brain changes in older adults. METHODS: We included 390 dementia-free participants aged 60+ from the Swedish National Study on Aging and Care in Kungsholmen who underwent brain magnetic resonance imaging at baseline and after 3 and/or 6 years. Using linear mixed models, we estimated the association between multimorbidity and changes in total brain tissue, ventricular, hippocampal, and white matter hyperintensities volumes. RESULTS: Compared to non-multimorbid participants, those with complex multimorbidity showed the steepest reduction in total brain (ß*time -0.03, 95% CI -0.05, -0.01) and hippocampal (ß*time -0.05, 95% CI -0.08, -0.03) volumes, the greatest ventricular enlargement (ß*time 0.03, 95% CI 0.01, 0.05), and the fastest white matter hyperintensities accumulation (ß*time 0.04, 95% CI 0.01, 0.07). DISCUSSION: Multimorbidity, particularly when involving multiple body systems, is associated with accelerated structural brain changes, involving both neurodegeneration and vascular pathology. HIGHLIGHTS: Multimorbidity accelerates structural brain changes in cognitively intact older adults These brain changes encompass both neurodegeneration and cerebrovascular pathology The complexity of multimorbidity is associated with the rate of brain changes' progression.

Associations of Orthostatic Hypotension and Frailty With Dementia and Mortality in Older Adults: A Population-Based Cohort Study.

BACKGROUND: This study aimed to assess the associations of orthostatic hypotension (OH), in the presence or absence of frailty, with dementia and mortality in older adults. METHODS: We conducted a 15-year population-based cohort study including 2 703 baseline dementia-free individuals from the Swedish National Study on Aging and Care in Kungsholmen. At baseline, OH was defined as a decline in systolic/diastolic blood pressure ≥20/10 mm Hg 1 minute after standing up from a supine position. Frailty status was defined following Fried's frailty phenotype. Dementia was diagnosed following the Diagnostic and Statistical Manual of Mental Disorders-fourth edition criteria. Multistate flexible parametric survival models were used to estimate associations of OH and frailty with dementia and mortality. RESULTS: Robust people with OH (adjusted hazard ratio [HR] = 2.28; 95% confidence interval [CI] = 1.47-3.54) and frail people without OH (HR = 1.98; 95% CI = 1.40-2.82) or with OH (HR = 2.73; 95% CI = 1.82-4.10) had a higher dementia risk than OH-free and robust people. Moreover, frail people, independently of the presence of OH, had higher mortality rate than OH-free and robust people. In individuals who developed dementia during the follow-up period, neither OH nor frailty was significantly associated with mortality. CONCLUSIONS: Older adults with OH, whether robust or frail, may have a higher dementia risk than those without OH. Older adults with OH, when having frailty, may have a higher mortality rate than those without OH. The concurrent assessments of OH and frailty may provide prognostic values in terms of dementia and mortality risk in older adults.

Living Longer But Frailer? Temporal Trends in Life Expectancy and Frailty in Older Swedish Adults.

BACKGROUND: This study aims to examine temporal trends in frailty state transitions, and years spent frail, in older Swedish adults. METHODS: We followed the Swedish National Study on Aging and Care in Kungsholmen participants from baseline (2001-2004) for 15 (median: 9.6) years. A 40-deficit frailty index (FI) was constructed to identify 3 frailty states: robust (FI ≤ 0.125), mild frailty (0.125 < FI ≤ 0.25), and moderate and severe frailty (FI  > 0.25). Multistate survival analyses were implemented to obtain hazard ratios (HRs) for frailty state transitions, with birth year and sex as predictors. To examine temporal trends, frailty state-specific life expectancies at age 60 were forecasted for robust persons born in different years (1900, 1910, 1920, 1930, and 1940), also by sex. RESULTS: At baseline, the 2 941 participants' mean age was 75 years and 65% were women. Predicted life expectancy and time spent frail from age 60 followed an increasing trend by birth year. Hazards of transitioning from mild frailty to death (HR: 0.89; 95% confidence interval [CI]: 0.83-0.97) and moderate and severe frailty to death (HR: 0.98; 95% CI: 0.97-1.00) were lower for those born later. Women were less likely to transition from robust to mild frailty (HR: 0.81; 95% CI: 0.70-0.93), mild frailty to moderate and severe frailty (HR: 0.80; 95% CI: 0.68-0.93), and moderate and severe frailty to death (HR: 0.68; 95% CI: 0.59-0.78), but spent more time frail. CONCLUSIONS: Our results point to an expansion of time spent frail among older Swedish adults over time.

Multimorbidity, cognitive phenotypes, and Alzheimer's disease plasma biomarkers in older adults: A population-based study.

INTRODUCTION: To examine the burden and clusters of multimorbidity in association with mild cognitive impairment (MCI), dementia, and Alzheimer's disease (AD)-related plasma biomarkers among older adults. METHODS: This population-based study included 5432 participants (age ≥60 years); of these, plasma amyloid beta (Aß), total tau, and neurofilament light chain (NfL) were measured in a subsample (n = 1412). We used hierarchical clustering to generate five multimorbidity clusters from 23 chronic diseases. We diagnosed dementia and MCI following international criteria. Data were analyzed using logistic and linear regression models. RESULTS: The number of chronic diseases was associated with dementia (multivariable-adjusted odds ratio = 1.22; 95% confidence interval [CI] = 1.11 to 1.33), AD (1.13; 1.01 to 1.26), vascular dementia (VaD) (1.44; 1.25 to 1.64), and non-amnestic MCI (1.25; 1.13 to 1.37). Metabolic cluster was associated with VaD and non-amnestic MCI, whereas degenerative ocular cluster was associated with AD (p < 0.05). The number of chronic diseases was associated with increased plasma Aß and NfL (p < 0.05). DISCUSSION: Multimorbidity burden and clusters are differentially associated with subtypes of dementia and MCI and AD-related plasma biomarkers in older adults. HIGHLIGHTS: We used hierarchical clustering to generate five clusters of multimorbidity. The presence and load of multimorbidity were associated with dementia and mild cognitive impairment. Multimorbidity clusters were differentially associated with subtypes of dementia and Alzheimer's disease plasma biomarkers.

Risk factors for multimorbidity in adulthood: A systematic review.

BACKGROUND: Multimorbidity, the coexistence of multiple chronic diseases in an individual, is highly prevalent and challenging for healthcare systems. However, its risk factors remain poorly understood. OBJECTIVE: To systematically review studies reporting multimorbidity risk factors. METHODS: A PRISMA-compliant systematic review was conducted, searching electronic databases (MEDLINE, EMBASE, Web of Science, Scopus). Inclusion criteria were studies addressing multimorbidity transitions, trajectories, continuous disease counts, and specific patterns. Non-human studies and participants under 18 were excluded. Associations between risk factors and multimorbidity onset were reported. RESULTS: Of 20,806 identified studies, 68 were included, with participants aged 18-105 from 23 countries. Nine risk factor categories were identified, including demographic, socioeconomic, and behavioral factors. Older age, low education, obesity, hypertension, depression, low pysical function were generally positively associated with multimorbidity. Results for factors like smoking, alcohol consumption, and dietary patterns were inconsistent. Study quality was moderate, with 16.2% having low risk of bias. CONCLUSIONS: Several risk factors seem to be consistently associated with an increased risk of accumulating chronic diseases over time. However, heterogeneity in settings, exposure and outcome, and baseline health of participants hampers robust conclusions.

Cognitive Change Among Nursing Home Residents: CogRisk-NH Scale Development to Predict Decline.

OBJECTIVES: Examine cognitive changes over time among nursing home residents and develop a risk model for identifying predictors of cognitive decline. DESIGN: Using secondary analysis design with Minimum Data Set data, cognitive status was based on the Cognitive Performance Scale (CPS). SETTING AND PARTICIPANTS: Baseline and 7 quarterly follow-up analyses of US and Canadian interRAI data (N = 1,257,832) were completed. METHODS: Logistic regression analyses identified predictors of decline to form the CogRisk-NH scale. RESULTS: At baseline, about 15% of residents were cognitively intact (CPS = 0), and 11.2% borderline intact (CPS = 1). The remaining more intact, with mild impairment (CPS = 2), included 15.0%. Approximately 59% residents fell into CPS categories 3 to 6 (moderate to severe impairment). Over time, increasing proportions of residents declined: 17.1% at 6 months, 21.6% at 9 months, and 34.0% at 21 months. Baseline CPS score was a strong predictor of decline. Categories 0 to 2 had 3-month decline rates in midteens, and categories 3 to 5 had an average decline rate about 9%. Consequently, a 2-submodel construction was employed-one for CPS categories 0 to 2 and the other for categories 3 to 5. Both models were integrated into a 6-category risk scale (CogRisk-NH). CogRisk-NH scale score distribution had 15.9% in category 1, 26.84% in category 2, and 36.7% in category 3. Three higher-risk categories (ie, 4-6) represented 20.6% of residents. Mean decline rates at the 3-month assessment ranged from 4.4% to 28.3%. Over time, differentiation among risk categories continued: 6.9% to 38.4.% at 6 months, 11.0% to 51.0% at 1 year, and 16.2% to 61.4% at 21 months, providing internal validation of the prediction model. CONCLUSIONS AND IMPLICATIONS: Cognitive decline rates were higher among residents in less-impaired CPS categories. CogRisk-NH scale differentiates those with low likelihood of decline from those with moderate likelihood and, finally, much higher likelihood of decline. Knowledge of resident risk for cognitive decline enables allocation of resources targeting amenable factors and potential interventions to mitigate continuing decline.

Relationship between People's Interest in Medication Adherence, Health Literacy, and Self-Care: An Infodemiological Analysis in the Pre- and Post-COVID-19 Era.

The prevalence of non-communicable diseases has risen sharply in recent years, particularly among older individuals who require complex drug regimens. Patients are increasingly required to manage their health through medication adherence and self-care, but about 50% of patients struggle to adhere to prescribed treatments. This study explored the relationship between interest in medication adherence, health literacy, and self-care and how it changed during the COVID-19 pandemic. We used Google Trends to measure relative search volumes (RSVs) for these three topics from 2012 to 2022. We found that interest in self-care increased the most over time, followed by health literacy and medication adherence. Direct correlations emerged between RSVs for medication adherence and health literacy (r = 0.674, p < 0.0001), medication adherence and self-care (r = 0.466, p < 0.0001), and health literacy and self-care (r = 0.545, p < 0.0001). After the COVID-19 pandemic outbreak, interest in self-care significantly increased, and Latin countries showed a greater interest in self-care than other geographical areas. This study suggests that people are increasingly interested in managing their health, especially in the context of the recent pandemic, and that infodemiology may provide interesting information about the attitudes of the population toward chronic disease management.

Ventricular Electrocardiographic Signatures Associated with Dementia and Plasma Alzheimer's Disease Biomarkers in Older Adults: A Population-Based Study.

BACKGROUND: Evidence has emerged that altered ventricular electrocardiogram profiles are associated with dementia, but the neuropathological mechanisms underlying their associations are poorly understood. OBJECTIVE: To investigate the interrelationships of ventricular electrocardiogram profiles with dementia and plasma Alzheimer's disease (AD) biomarkers among older adults. METHODS: This population-based cross-sectional study included 5,153 participants (age ≥65 years; 57.3% women) living in rural communities in China; of these, 1,281 had data on plasma amyloid-ß (Aß)40, Aß42, total-tau, and neurofilament light chain (NfL) protein. The QT, QTc, JT, JTc, QRS intervals, and QRS axis were derived from the 10-second electrocardiogram recording. The DSM-IV criteria were followed for clinical diagnosis of dementia, the NIA-AA criteria for AD, and the NINDS-AIREN criteria for vascular dementia (VaD). Data were analyzed using general linear models, multinomial logistic models, and restricted cubic splines. RESULTS: Of the 5,153 participants, 299 (5.8%) were diagnosed with dementia, including 194 with AD and 94 with VaD. Prolonged QT, QTc, JT, and JTc intervals were significantly associated with all-cause dementia, AD, and VaD (p < 0.05). Left QRS axis deviation was significantly associated with all-cause dementia and VaD (p < 0.01). In the subsample of plasma biomarkers (n = 1,281), prolonged QT, JT, and JTc intervals were significantly associated with a lower Aß42/Aß40 ratio and higher plasma NfL concentrations (p < 0.05). CONCLUSION: Alterations in ventricular repolarization and depolarization are independently associated with all-cause dementia, AD, VaD, and AD plasma biomarkers in older adults (age ≥65 years). Ventricular electrocardiogram parameters may be valuable clinical markers for dementia and the underlying AD pathologies and neurodegeneration.

Association of Long-term Exposure to Air Pollution and Dementia Risk: The Role of Homocysteine, Methionine, and Cardiovascular Burden.

BACKGROUND AND OBJECTIVES: Growing evidence links air pollution with dementia risk, but the biological mechanisms are largely unknown. We investigated the role played by homocysteine (tHcy) and methionine in this association and explored whether this could be explained by cardiovascular diseases (CVDs). METHODS: Data were extracted from the ongoing Swedish National study on Aging and Care in Kungsholmen (SNAC-K), a longitudinal population-based study. At baseline, 2,512 dementia-free participants were examined up to 2013 (mean follow-up: 5.18 ± 2.96 years). Two air pollutants (particulate matter ≤2.5 µm [PM2.5] and nitrogen oxides [NOx]) were assessed yearly from 1990 until 2013 using dispersion models at residential addresses. The hazard ratio of dementia over air pollution levels was estimated using Cox models adjusted for age, sex, education, smoking, socioeconomic status, physical activity, retirement age, creatinine, year of assessment, and the use of supplements. The total effect of air pollutants on dementia was decomposed into 4 pathways involving tHcy/methionine: (1) direct effect; (2) indirect effect (mediation); (3) effect due to interaction; and (4) effect due to both mediation and interaction. To test whether the association was independent from CVDs (ischemic heart disease, atrial fibrillation, heart failure, and stroke), we repeated the analyses excluding those individuals who developed CVDs. RESULTS: The mean age of the study participants was 73.4 years (SD: 10.4), and 62.1% were female individuals. During an average period of 5 years (mean: 5.18; SD: 2.96 years), 376 cases with incident dementia were identified. There was a 70% increased hazard of dementia per unit increase of PM2.5 during the 5 years before baseline (hazard ratio [HR]: 1.71; 95% CI 1.33-2.09). Overall, 50% (51.6%; 95% CI 9.0-94.1) of the total effect of PM2.5 on dementia was due to mediation of tHcy (6.6%; 95% CI 1.6-11.6) and/or interaction (47.8%; 95% CI 4.9-91.7) with tHcy and 48.4% (p = 0.03) to the direct effect of PM2.5 on dementia. High levels of methionine reduced the dementia hazard linked to PM2.5 by 31% (HR: 0.69; 95% CI 0.56-0.85) with 24.8% attributable to the interaction with methionine and 25.9% (p = 0.001) to the direct effect of PM2.5. No mediation effect was found through methionine. Attenuated results were obtained for NOx. Findings for tHcy were attenuated after excluding those who developed CVDs, while remained similar for methionine. DISCUSSION: High levels of homocysteine enhanced the dementia risk attributed to air pollution, while high methionine concentrations reduced this risk. The impact of homocysteine on cardiovascular conditions partly explains this association. Alternative pathways other than cardiovascular mechanisms may be at play between methionine and dementia.

Association Between Sensory Impairment and Dementia: The Roles of Social Network and Leisure Activity.

BACKGROUND: Evidence suggests that sensory impairment is linked to dementia; however, the role of social network and leisure activity in this relationship is unclear. OBJECTIVE: Examine the association of hearing and visual impairment with dementia, and whether a rich social network and leisure activity moderates this association. METHODS: Dementia-free older adults from the Swedish National Study on Aging and Care in Kungsholmen (n = 2,579) were followed up for up for a median of 10 years (interquartile range = 6). Visual impairment was assessed with a reading acuity test, and hearing impairment was ascertained via self-report and medical records. Dementia was diagnosed following international criteria. Data on social network and leisure activity was collected via self-report. Hazard ratios (HRs) of dementia risk were derived from Cox regression models. RESULTS: Dual impairment, but not single impairment in hearing and vision was associated with a higher risk of dementia (HR: 1.62, 95% CI: 1.16 to 2.27). Compared to participants with no sensory impairment and a moderate-to-rich social network, those with dual impairment and low social network or leisure activity had higher dementia risk (HR: 2.08, 95% CI: 1.43 to 3.22; HR: 2.08, 95% CI: 1.43 to 3.22, respectively), whereas participants with dual impairment with a moderate-to-rich social network or leisure activity did not have significantly higher dementia risk (HR; 1.42, 95% CI: 0.87 to 2.33; HR; 1.42, 95% CI: 0.87 to 2.33, respectively). CONCLUSION: A richer social network and participation in stimulating activities may mitigate the higher dementia risk in older adults with dual impairment in vision and hearing.

Multimorbidity patterns and 18-year transitions from normal cognition to dementia and death: A population-based study.

BACKGROUND: Several chronic diseases accelerate cognitive decline; however, it is still unknown how different patterns of multimorbidity influence individuals' trajectories across the cognitive continuum. OBJECTIVES: We aimed to investigate the impact of multimorbidity and of specific multimorbidity patterns on the transitions across cognitive stages (normal cognition, cognitive impairment, no dementia [CIND], dementia) and death. METHODS: We included 3122 dementia-free individuals from the Swedish National study on Aging and Care in Kungsholmen. Using fuzzy c-means cluster analysis, multimorbid participants were classified into mutually exclusive groups characterized by commonly coexisting chronic diseases. Participants were followed up to 18 years to detect incident CIND, dementia, or death. Transition hazard ratios (HRs), life expectancies, and time spent in different cognitive stages were estimated using multistate Markov models. RESULTS: At baseline, five multimorbidity patterns were identified: neuropsychiatric, cardiovascular, sensory impairment/cancer, respiratory/metabolic/musculoskeletal, and unspecific. Compared to the unspecific pattern, the neuropsychiatric and sensory impairment/cancer ones showed reduced hazards of reverting from CIND to normal cognition (HR 0.53, 95% CI 0.33-0.85 and HR 0.60, 95% CI 0.39-0.91). Participants in the cardiovascular pattern exhibited an increased hazard of progression from CIND to dementia (HR 1.70, 95% CI 1.15-2.52) and for all transitions to death. Subjects with the neuropsychiatric and cardiovascular patterns showed reduced life expectancy at age 75, with an anticipation of CIND (up to 1.6 and 2.2 years, respectively) and dementia onset (up to 1.8 and 3.3 years, respectively). CONCLUSIONS: Multimorbidity patterns differentially steer individual trajectories across the cognitive continuum of older adults and may be used as a risk stratification tool.

Role of Orthostatic Hypotension in the Development of Dementia in People With and Without Cardiovascular Disease.

BACKGROUND: Orthostatic hypotension (OH) has been associated with elevated risk of cardiovascular diseases (CVDs) and dementia risk. To better understand the OH-dementia association, we assessed the associations of OH with CVD and subsequent dementia in older adults and considered the temporality of CVD and dementia onset. METHODS: This 15-year population-based cohort study included, at baseline, 2703 dementia-free participants (mean age, 73.7 years) who were divided into a CVD-free cohort (n=1986) and a CVD cohort (n=717). OH was defined as a systolic/diastolic blood pressure decline of ≥20/10 mm Hg after standing up from a supine position. CVDs and dementia were ascertained by physicians or identified from registers. Multistate Cox regressions were applied to assess the associations of OH with CVD and subsequent dementia in the CVD-free and dementia-free cohort. The OH-dementia association in the CVD cohort was examined with Cox regressions. RESULTS: OH was present in 434 (21.9%) individuals in the CVD-free cohort and 180 (25.1%) individuals in the CVD cohort. OH was associated with a hazard ratio of 1.33 (95% CI, 1.12-1.59) for CVD. OH was not significantly associated with incident dementia in the absence of CVD occurring before dementia diagnosis (hazard ratio, 1.22 [95% CI, 0.83-1.81]). In the CVD cohort, individuals with OH had a higher dementia risk than those without OH (hazard ratio, 1.54 [95% CI, 1.06-2.23]). CONCLUSIONS: The association between OH and dementia may partly be explained by the intermediate development of CVD. In addition, in people with CVD, those with OH may have a poorer cognitive prognosis.

A glycan epitope correlates with tau in serum and predicts progression to Alzheimer's disease in combination with APOE4 allele status.

INTRODUCTION: There is an urgent need for novel blood biomarkers for the detection of Alzheimer's disease (AD). We previously showed that levels of the bisecting N-acetylglucosamine glycan epitope was elevated in cerebrospinal fluid in AD. However, its diagnostic value in blood is unknown. METHODS: We analyzed blood levels of bisecting N-acetylglucosamine and total tau in a retrospective cohort of 233 individuals. Progression to AD was compared between the groups using Cox regression. The predictive value of the biomarkers was determined by logistic regression. RESULTS: Bisecting N-acetylglucosamine correlated with tau levels (p < 0.0001). Individuals with an intermediate tau/bisecting N-acetylglucosamine ratio had elevated AD risk (hazard ratio = 2.06, 95% confidence interval [CI]: 1.18-3.6). Moreover, a combined model including tau/bisecting N-acetylglucosamine ratio, apolipoprotein E (APOE) ε4 status, and Mini-Mental State Examination score predicted future AD (area under the curve = 0.81, 95% CI: 0.68-0.93). DISCUSSION: Bisecting N-acetylglucosamine in combination with tau is a valuable blood biomarker for predicting AD.