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Introduction: Evidence supporting cardiovascular diseases could increase the risk of dementia remains fragmented. A comprehensive study to illuminate the distinctive associations across different dementia types is still lacking. This study is sought to: (1) determine the clinical validity of Framingham General Cardiovascular Risk Score (FGCRS) for dementia assessment and (2) examine the associations between cardiovascular diseases and the risk of dementia., Methods: A total of 432 079 dementia-free individuals at baseline from UK Biobank were included. Multivariable Cox proportional hazard models were used to investigate the prospective associations for FGCRS and a series of cardiovascular diseases with all-cause dementia (ACD) and its major components, Alzheimer's disease (AD) and vascular dementia (VaD)., Results: During a median follow-up of 110.1 months, 4711 individuals were diagnosed with dementia. FGCRS was associated with increased risks across the dementia spectrum. In stratification analysis, high-risk groups have demonstrated the greatest dementia burdens, particularly to VaD. Over 74 traits, 9 adverse associations, such as chronic ischaemic heart disease (ACD: HR=1.354; AD: HR=1.269; VaD: HR=1.768), atrioventricular block (ACD: HR=1.562; AD: HR=1.556; VaD: HR=2.069), heart failure (ACD: HR=1.639; AD: HR=1.543; VaD: HR=2.141) and hypotension (ACD: HR=2.912; AD: HR=2.361; VaD: HR=3.315) were observed. Several distinctions were also found, with atrial fibrillation, cerebral infarction, and haemorrhage only associated with greater risks of ACD and VaD., Discussion: By identifying distinctive associations between cardiovascular diseases and dementia, this study has established a comprehensive 'mapping' that may untangle the long-standing discrepancy. FGCRS has demonstrated its predictivity beyond cardiovascular diseases burdens, suggesting potential opportunities for implantation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: Apply established cerebrospinal fluid (CSF) and serum biomarkers and novel combined indicators based on the amyloid/tau/neurodegeneration (ATN) framework to improve diagnostic and prognostic power in patients with rapidly progressive dementias (RPDs)., Methods: CSF and serum biomarkers of Alzheimer's disease (AD) common neuropathology including Aβ42, Aβ40, p-Tau, and t-Tau were measured in cognitively normal (CN) controls (n = 33) and three RPD groups with rapidly progressive AD (rpAD, n = 23), autoimmune encephalitis (AE, n = 25), and Creutzfeldt-Jakob disease (CJD, n = 28). Logistic regression and multiple linear regression were used for producing combined indicators and prognostic assessment, respectively, including A&T, A&N, T&N, A&T&N, etc. RESULTS: Combined diagnostic indicator with A&T&N had the potential for differentiating AE from other types of RPDs, identifying 62.51% and 75% of AE subjects based on CSF and serum samples, respectively, compared to 39.13% and 37.5% when using autoantibodies. CSF t-Tau was associated with survival in the CJD group (adjusted R-Square = 0.16, p = 0.02), and its prognosis value improved when using combined predictors based on the ATN framework (adjusted R-Square = 0.273, p = 0.014)., Conclusion: Combined indicators based on the ATN framework provide a novel perspective for establishing biomarkers for early recognition of RPDs due to treatment-responsive causes., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Previous hypothesis-driven research has identified many risk factors linked to dementia. However, the multiplicity and co-occurrence of risk factors have been underestimated. Here we analysed data of 344,324 participants from the UK Biobank with 15 yr of follow-up data for 210 modifiable risk factors. We first conducted an exposure-wide association study and then combined factors associated with dementia to generate composite scores for different domains. We then evaluated their joint associations with dementia in a multivariate Cox model. We estimated the potential impact of eliminating the unfavourable profiles of risk domains on dementia using population attributable fraction. The associations varied by domain, with lifestyle (16.6%), medical history (14.0%) and socioeconomic status (13.5%) contributing to the majority of dementia cases. Overall, we estimated that up to 47.0%-72.6% of dementia cases could be prevented., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: The purpose of this study was to investigate the associations between courses of depression, the application of depression treatment, and the risk of incident dementia., Methods: In this prospective cohort study, 354,313 participants ages 50-70 years were recruited from the UK Biobank between 2006 and 2010 and were followed until 2020, with a total of 4,212,929 person-years. We initially studied the effect of depression on dementia incidence across 4 subgroups characterized by courses of depressive symptoms. Then, 46,820 participants with a diagnosis of depression were further categorized into treated and untreated groups. We compared the risk of dementia among different depression treatment groups in all participants who were depressed as well as 4 courses of depressive symptoms by performing survival analyses., Results: Depression was associated with a 51% higher risk of dementia, among which the increasing, chronically high, and chronically low courses were associated with increased dementia risk, while no association was found in the decreasing course. Compared to those who were depressed but untreated, receiving depression treatments corresponded to a hazard ratio of 0.7 (95% CI, 0.62-0.77). Among the 3 detrimental courses, treatments for increasing and chronically low symptoms of depression were associated with a 32% and 28% lower risk of dementia, respectively, while the reduction effect for chronically high symptoms was insignificant., Conclusions: The negative association between depression treatment and incident dementia was significant in the increasing and chronically low courses, highlighting the necessity of timely interventional strategies before depression progresses to a chronically severe state., (Copyright © 2022 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: The association between poor oral health and the risk of incident dementia remains unclear., Objective: To investigate the associations of poor oral health with incident dementia, cognitive decline, and brain structure in a large population-based cohort study., Methods: A total of 425,183 participants free of dementia at baseline were included from the UK Biobank study. The associations between oral health problems (mouth ulcers, painful gums, bleeding gums, loose teeth, toothaches, and dentures) and incident dementia were examined using Cox proportional hazards models. Mixed linear models were used to investigate whether oral health problems were associated with prospective cognitive decline. We examined the associations between oral health problems and regional cortical surface area using linear regression models. We further explored the potential mediating effects underlying the relationships between oral health problems and dementia., Results: Painful gums (HR = 1.47, 95% CI [1.317-1.647], p < 0.001), toothaches (HR = 1.38, 95% CI [1.244-1.538], p < 0.001), and dentures (HR = 1.28, 95% CI [1.223-1.349], p < 0.001) were associated with increased risk of incident dementia. Dentures were associated with a faster decline in cognitive functions, including longer reaction time, worse numeric memory, and worse prospective memory. Participants with dentures had smaller surface areas of the inferior temporal cortex, inferior parietal cortex, and middle temporal cortex. Brain structural changes, smoking, alcohol drinking, and diabetes may mediate the associations between oral health problems and incident dementia., Conclusion: Poor oral health is associated with a higher risk of incident dementia. Dentures may predict accelerated cognitive decline and are associated with regional cortical surface area changes. Improvement of oral health care could be beneficial for the prevention of dementia.

Competing Interests: J-TY is the principal investigator for the China Healthy Aging and Dementia (HEAD) study (funded by Science and Technology Innovation 2030 Major Projects, 2022ZD0211600). All other authors declare no competing interests.

Based on risk profiles, several approaches for predicting dementia risk have been developed. Predicting the risk of dementia with accuracy is a significant clinical challenge. The goal was to create a modified dementia risk score (MDRS) based on a big sample size. A total of 239,745 participants from UK Biobank were studied (mean follow-up of 8.7 years). The score value of each risk factor was estimated according to the β coefficient in the logistic regression model. The total dementia risk score was the sum of each risk score. Kaplan Meier survival curves and Cox proportional hazards analyses were used to assess the associations between total score and dementia. Among all participants included, 3531 incident cases of all-cause dementia (ACD), 1729 cases of Alzheimer's disease (AD), and 925 cases of vascular dementia (VD) were identified. Several vascular risk factors (physical activity, current smoking status, and glycemic status) and depressive symptoms were found to be significantly related to dementia risk. The modified dementia risk scores predicted dementia well (model 1, area under curve 0.810; model 2, area under curve 0.832). In model 1, the cut-off value for high risk (HR) was 81 or higher, and in model 2 (including the APOE4), it was 98 or higher. According to Kaplan-Meier survival analyses, patients in the HR group had faster clinical progression (p < 0.0001) in either model 1 or 2. Cox regression analyses for HR versus low risk (LR) revealed that the Hazard radio for ACD was 7.541 (6.941 to 8.193) in model 1 and 8.348 (7.727 to 9.019) in model 2. MDRS is appropriate for dementia primary prevention, and may help quickly identify individuals with elevated risk of dementia., (© 2022. The Author(s).)

Multimorbidity (the presence of two or more long-term conditions [LTCs]) was suggested to exacerbate the neuronal injuries. The impact of multimorbidity on dementia has not been fully elucidated. We aimed to investigate the association between multimorbidity and dementia risk. We used the prospective data from 245,483 UK Biobank participants during a 9-year follow-up. Multimorbidity status was evaluated based on the LTC counts and multimorbidity patterns. Cox regression models adjusted for potential confounders were used to examine the associations of multimorbidity status with all-cause dementia (ACD), Alzheimer's disease (AD) and vascular dementia (VD). Participants with multimorbidity at baseline had higher risks of ACD and VD, and the risks were elevated with the increase of LTC counts (ACD: hazard ratios [HR] = 1.15, 95% confidence intervals [CI] = 1.01-1.31 with 2 LTCs; HR = 1.18, CI = 1.01-1.39 with 3 LTCs; HR = 1.65, CI = 1.44-1.88 with ≥4 LTCs; VD: HR = 1. 66, CI = 1.24-2.21 with 2 LTCs; HR = 2.10, CI = 1.53-2.88 with 3 LTCs; HR = 3.17, CI = 2.43-4.13 with ≥4 LTCs). Participants with ≥4 LTCs also had a higher risk of AD (HR = 1.34, CI = 1.08-1.66]. Participants with the cardio-cerebrovascular/respiratory/metabolic/musculoskeletal/depressive multimorbidity were 1.46, 1.28, and 2.50 times more likely to develop ACD (HR = 1.46, 95% CI = 1.28-1.67), AD (HR = 1.28, CI = 1.04-1.58), and VD (HR = 2.50, CI = 1.90-3.27), respectively. Those with tumor/genitourinary/digestive disorders had a 11% higher hazard of ACD (HR = 1.11, CI = 1.00-1.24) and a 73% elevated risk of VD (HR = 1.73, CI = 1.37-2.18). The prevention of LTC accumulation and the identification of specific multimorbidity patterns might be beneficial to the prevention of dementia and its subtypes, AD as well as VD., (© 2022. The Author(s).)

Although sleep, physical activity and sedentary behavior have been found to be associated with dementia risk, findings are inconsistent and their joint relationship remains unclear. This study aimed to investigate independent and joint associations of these three modifiable behaviors with dementia risks. A total of 431,924 participants (median follow-up 9.0 years) without dementia from UK Biobank were included. Multiple Cox regressions were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Models fitted with restricted cubic spline were conducted to test for linear and nonlinear shapes of each association. Sleep duration, leisure-time physical activity (LTPA), and screen-based sedentary behavior individually associated with dementia risks in different non-linear patterns. Sleep duration associated with dementia in a U-shape with a nadir at 7 h/day. LTPA revealed a curvilinear relationship with dementia in diminishing tendency, while sedentary behavior revealed a J-shaped relationship. The dementia risk was 17% lower in the high LTPA group (HR[95%CI]: 0.83[0.76-0.91]) and 22% higher in the high sedentary behavior group (1.22[1.10-1.35]) compared to the corresponding low-level group, respectively. A combination of seven-hour/day sleep, moderate-to-high LTPA, and low-to-moderate sedentary behavior showed the lowest dementia risk (0.59[0.50-0.69]) compared to the referent group (longer or shorter sleep/low LTPA/high sedentary behavior). Notably, each behavior was non-linearly associated with brain structures in a pattern similar to its association with dementia, suggesting they may affect dementia risk by affecting brain structures. Our findings highlight the potential to change these three daily behaviors individually and simultaneously to reduce the risk of dementia., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Immune system dysregulation plays a vital role in the pathogenesis of neurodegenerative diseases, even considered to be as important as classical pathological protein aggregation assumption. However, the associations of immune-mediated diseases with incident dementia are unclear and need to be clarified in prospective studies with a large population and long follow-up time., Methods: We investigated the relationship between any or individual immune-mediated diseases and incident dementia based on a prospective cohort UK Biobank. The risk for dementia was assessed with multivariable hazard ratio (HR) and 95% confidence interval (CI) after adjusting for various potential confounders using time-varying Cox proportional hazards regression. We also performed the subgroup Cox analysis stratified by time since immune-mediated diseases and gender. Causal mediation analyses with 1000 bootstrapped iterations were conducted to explore the mediation effects of peripheral immune cells on the associations of immune-mediated diseases with dementia., Results: A total of 375,894 participants were included in the study, among which 5291 developed dementia during a median follow-up of 9.08 years. Immune-mediated diseases were associated with an increased risk of dementia (HR, 1.10; 95% CI, 1.00-1.21), and the risk was highest between 1 and 2 years after immune-mediated diseases onset (HR, 2.74; 95% CI, 1.86-4.04). Females who suffered from immune-mediated diseases were more prone to AD, while males were more susceptible to VD. Four of the individual immune-mediated diseases including type I diabetes mellitus (HR, 2.49; 95% CI, 1.97-3.15), rheumatic fever or rheumatic heart diseases (HR, 1.36; 95% CI, 1.05-1.77), multiple sclerosis (HR, 2.87; 95% CI, 1.92-4.30), and necrotizing vasculopathies (HR, 1.71; 95%CI, 1.03-2.85) were significantly related to higher dementia incidence. The relationship between immune-mediated diseases and dementia was partially mediated by peripheral immune cells including neutrophils and lymphocytes., Conclusions: In this large cohort study, immune-mediated diseases were proven to be significantly associated with an increased risk of incident dementia, especially for type I diabetes mellitus which was observed to be related to the higher incidence of all types of dementia. Our findings could provide new sights on dementia pathogenesis and intervention from the perspective of systemic immunology and immune-mediated diseases., (© 2022. The Author(s).)

Prevention of dementia is a public health priority, and the identification of potential biomarkers may provide benefits for early detection and prevention. This study investigates the association of common serum laboratory tests with the risk of incident dementia. Among 407,190 participants from the UK Biobank (median follow-up of 9.19 years), we investigated the linear and nonlinear effects of 30 laboratory measures on the risk of all-cause dementia using Cox models and restricted cubic spline models. We found that dementia incidence was associated with low vitamin D concentration (hazard ratio 0.994, 95% confidence interval 0.993-0.996), indicators of endocrine disorders: IGF-1 level (P for non-linearity = 1.1E-05), testosterone level (P for non-linearity = 0.006); high sex-hormone-binding globulin level (HR 1.004, 95% CI: 1.003-1.006); reduced liver function: lower alanine aminotransferase (HR 0.990, 95% CI: 0.986-0.995); renal dysfunction: cystatin C level (P for non-linearity = 0.028); oxidative stress: lower urate level (HR 0.998, 95% CI: 0.998-0.999); lipids dysregulation: lower LDL (HR 0.918, 95% CI: 0.872-0.965) and triglycerides (HR 0.924, 95% CI: 0.882-0.967) concentrations; insulin resistance: high glucose (HR 1.093, 95% CI: 1.045-1.143) and HbA1c (HR 1.017, 95% CI: 1.009-1.025) levels; immune dysbiosis: C-reactive protein (P for non-linearity = 5.5E-09). In conclusion, markers of vitamin D deficiency, GH-IGF-1 axis disorders, bioactive sex hormone deficiency, reduced liver function, renal abnormalities, oxidation, insulin resistance, immune dysbiosis, and lipids dysregulation were associated with incident dementia. Our results support a contributory role of systemic disorders and diverse biological processes to onset of dementia., (© 2022. The Author(s).)

Cohort studies report inconsistent associations between body mass index (BMI) and all-cause incident dementia. Furthermore, evidence on fat distribution and body composition measures are scarce and few studies estimated the association between early life adiposity and dementia risk. Here, we included 322,336 participants from UK biobank to investigate the longitudinal association between life course adiposity and risk of all-cause incident dementia and to explore the underlying mechanisms driven by metabolites, inflammatory cells and brain structures. Among the 322,336 individuals (mean (SD) age, 62.24 (5.41) years; 53.9% women) in the study, during a median 8.74 years of follow-up, 5083 all-cause incident dementia events occurred. The risk of dementia was 22% higher with plumper childhood body size (p < 0.001). A strong U-shaped association was observed between adult BMI and dementia. More fat and less fat-free mass distribution on arms were associated with a higher risk of dementia. Interestingly, similar U-shaped associations were found between BMI and four metabolites (i.e., 3-hydroxybutrate, acetone, citrate and polyunsaturated fatty acids), four inflammatory cells (i.e., neutrophil, lymphocyte, monocyte and leukocyte) and abnormalities in brain structure that were also related to dementia. The findings that adiposity is associated with metabolites, inflammatory cells and abnormalities in brain structure that were related to dementia risk might provide clues to underlying biological mechanisms. Interventions to prevent dementia should begin early in life and include not only BMI control but fat distribution and body composition., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Central immunity components especially microglia in dementia have been well studied and corresponding immunotherapy gradually caught the attention. However, few studies focused on peripheral immunity and dementia. To address the issue, we examined the longitudinal association between incident dementia and peripheral immunity markers encompassing immune cell counts, and their derived ratios including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and lymphocyte-to-monocyte ratio (LMR), utilizing data of 361,653 participants from the UK Biobank (UKB). During a median follow-up of 8.99 years, 4239 participants developed dementia. The results revealed that increased innate immunity markers were associated with higher dementia risk (per SD increment hazard ratio [HR]; 95% confidence interval [CI] 1.14; 1.09-1.19 for neutrophils, 1.16; 1.11-1.20 for NLR and 1.11; 1.07-1.16 for SII), while increased adaptive immunity markers were associated with lower dementia risk (0.93; 0.90-0.97 for lymphocytes and 0.94; 0.90-0.98 for LMR). Our study pinpoints the differential role of innate and adaptive immunity in dementia incidence, which may provide some new perspectives in etiology and therapy of dementia., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Dementia is a challenging neurodegenerative disease. This systematic review aimed to summarize natural, physical, and social environmental factors that are associated with age-related cognitive impairment and dementia., Methods: We systematically searched PubMed, EMBASE, Web of Science, and PsychINFO till January 11, 2021 for observational studies. The hazard ratio (HR), relative risk (RR), and odds ratio (OR) with 95% confidence interval (CI) were aggregated using random-effects methods. The quality of evidence for each association was evaluated., Results: Of the 48,399 publications identified, there were 185 suitable for review across 44 environmental factors. Meta-analyses were performed for 22 factors. With high-to-moderate quality of evidence, risks were suggested in exposure to PM 2.5 (HR=1.24, 95%CI: 1.17-1.31), NO 2 (HR=1.07, 95%CI: 1.02-1.12), aluminum (OR=1.35, 95%CI: 1.14-1.59), solvents (OR=1.14, 95%CI: 1.07-1.22), road proximity (OR=1.08, 95%CI: 1.04-1.12) and other air pollutions, yet more frequent social contact (HR=0.82, 95%CI: 0.76-0.90) and more greenness (OR=0.97, 95%CI: 0.95-0.995) were protective. With low-to-very low quality, electromagnetic fields, pesticides, SO 2 , neighborhood socioeconomic status, and rural living were suggested risks, but more community cultural engagement might be protective. No significant associations were observed in exposure to PM 10 , NO x , noise, silicon, community group, and temperature. For the remaining 22 factors, only a descriptive analysis was undertaken as too few studies or lack of information., Conclusions: This review highlights that air pollutions, especially PM 2.5 and NO 2 play important role in the risk for age-related cognitive impairment and dementia., (Copyright © 2021. Published by Elsevier B.V.)

Identifying circulating metabolites associated with dementia, cognition, and brain volume may improve the understanding of dementia pathogenesis and provide novel insights for preventive and therapeutic interventions. This cohort study included a total of 87 885 participants (median follow‐up of 9.1 years, 54% female) without dementia at baseline from the UK Biobank. A total of 249 plasma metabolites were measured using nuclear magnetic resonance spectroscopy at baseline. Cox proportional regression was used to examine the associations of each metabolite with incident dementia (cases = 1134), Alzheimer's disease (AD; cases = 488), and vascular dementia (VD; cases = 257) during follow‐up. Dementia‐associated metabolites were further analyzed for association with cognitive deficits (N = 87 885) and brain volume (N = 7756) using logistic regression and linear regression. We identified 26 metabolites associated with incident dementia, of which 6 were associated with incident AD and 5 were associated with incident VD. These 26 dementia‐related metabolites were subfractions of intermediate‐density lipoprotein, large low‐density lipoprotein (L‐LDL), small high‐density lipoprotein (S‐HDL), very‐low‐density lipoprotein, fatty acids, ketone bodies, citrate, glucose, and valine. Among them, the cholesterol percentage in L‐LDL (L‐LDL‐C%) was associated with lower risk of AD (HR [95% CI] = 0.92 [0.87–0.97], p = 0.002), higher brain cortical (β = 0.047, p = 3.91 × 10−6), and hippocampal (β = 0.043, p = 1.93 × 10−4) volume. Cholesteryl ester–to–total lipid ratio in L‐LDL (L‐LDL‐CE%) was associated with lower risk of AD (HR [95% CI] = 0.93 [0.90–0.96], p = 1.48 × 10−4), cognitive deficits (odds ratio = 0.98, p = 0.009), and higher hippocampal volume (β = 0.027, p = 0.009). Cholesteryl esters in S‐HDL (S‐HDL‐CE) were associated with lower risk of VD (HR [95% CI] = 0.81 [0.71–0.93], p = 0.002), but not AD. Taken together, circulating levels of L‐LDL‐CE% and L‐LDL‐C% were robustly associated with risk of AD and AD phenotypes, but not with VD. S‐HDL‐CE was associated with lower risk of VD, but not with AD or AD phenotypes. These metabolites may play a role in the advancement of future intervention trials. Additional research is necessary to gain a complete comprehension of the molecular mechanisms behind these associations. [ABSTRACT FROM AUTHOR]

Introduction: Low hemoglobin and anemia are associated with cognitive impairment and Alzheimer's disease (AD). However, the associations of other blood cell indices with incident dementia risk and the underlined mechanisms are unknown. Methods: Three hundred thirteen thousand four hundred forty‐eight participants from the UK Biobank were included. Cox and restricted cubic spline models were used to investigate linear and non‐linear longitudinal associations. Mendelian randomization analysis was used to identify causal associations. Linear regression models were used to explore potential mechanisms driven by brain structures. Results: During a mean follow‐up of 9.03 years, 6833 participants developed dementia. Eighteen indices were associated with dementia risk regarding erythrocytes, immature erythrocytes, and leukocytes. Anemia was associated with a 56% higher risk of developing dementia. Hemoglobin and red blood cell distribution width were causally associated with AD. Extensive associations exist between most blood cell indices and brain structures. Discussion: These findings consolidated associations between blood cells and dementia. Highlight: Anemia was associated with 56% higher risk for all‐cause dementia.Hematocrit percentage, mean corpuscular volume, platelet crit, and mean platelet volume had U‐shaped associations with incident dementia risk.Hemoglobin (HGB) and red blood cell distribution width had causal effects on Alzheimer's risk.HGB and anemia were associated with brain structure alterations. [ABSTRACT FROM AUTHOR]

Visual impairment and interventions to preserve vision may impact dementia risk. Thus, we aimed to explore the associations of cataract and cataract surgery with the risk of dementia. Prospective data from 300,823 individuals in the UK Biobank were used. We used multivariate Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals for associations, with healthy control subjects as a reference. The same method was used to explore the effects of surgery on dementia outcomes of patients with cataract. One-way analysis of variance was performed to examine the associations between cataract and brain morphometric measures. After a mean follow-up of 8.4 years, 3226 individuals were diagnosed with dementia. The nonsurgical cataract group had increased risk of all-cause dementia (HR, 1.214; 95% CI, 1.012–1.456; p =.037) and Alzheimer's disease (HR, 1.479; 95% CI, 1.105–1.981; p =.009). However, there was no difference in dementia risk between the cataract surgery group and the healthy control group. Cataract surgery was associated with decreased risk of all-cause dementia (HR, 0.632; 95% CI, 0.421–0.947; p =.026) and Alzheimer's disease (HR, 0.399; 95% CI, 0.196–0.812; p =.011) compared with the nonsurgical group. Additionally, cataract was negatively associated with cortical volumes, aging-related subcortical volumes, and fractional anisotropy of white matter fibers. Cataract patients who did not receive surgical treatment had an increased risk of dementia. However, cataract surgery could reverse the risk of dementia. Our findings on brain structures and pathways in patients with cataract also provided evidence for the mechanism. Reversible visual impairment, such as cataract, is a promising modifiable risk factor for dementia. [ABSTRACT FROM AUTHOR]

Introduction: Grip strength and walking pace have been linked to cognitive dysfunction. Their relationships, however, demand further clarification as the evidence is derived primarily from less‐comprehensive investigations. Methods: A total of 340212 UK Biobank participants without dementia and cardiovascular diseases at baseline were analyzed. Cox proportional hazard models assessed the longitudinal associations. Results: Over a mean follow‐up of 8.51 ± 2.68 years, 2424 incident dementia cases were documented. A 5 kg increment of absolute grip strength was associated with lower risks of all‐cause dementia (hazard ratio [HR] 0.857), Alzheimer's disease (HR 0.874), and vascular dementia (HR 0.788). The patterns of associations remained similar when grip strength was expressed in relative terms and quintiles. A slow walking pace demonstrated consistent associations with increased risks of all dementia types. Discussion: Our findings provide amplified evidence and suggest that muscle fitness, reflected by objective grip strength measures and self‐reported walking pace, may be imperative for estimating the risks of dementia. [ABSTRACT FROM AUTHOR]

Background: Dementia and cognitive impairment can be attributed to genetic and modifiable factors. Considerable evidence emerged in modifiable factors and urgently requires standardized evaluation. We conducted an umbrella review to evaluate the strength and validity of the existing evidence.Methods: We searched PubMed, Embase, CINAHL and Cochrane Database of Systematic Reviews to identify relevant systematic reviews and meta-analyses of prospective studies regarding the associations of dementia and cognitive impairment with modifiable factors. For each association, we analyzed the summary effect size, 95 % confidence interval, 95 % prediction interval, heterogeneity, small study effect and excess significance bias. Mendelian randomization studies were descriptively reviewed further exploring the causality of the associations.Results: In total, 12,015 articles were identified, of which 118 eligible studies yielded 243 unique associations. Convincing evidence was found for associations of dementia and cognitive impairment with early-life education, midlife to late-life plasma glucose, BMI, atrial fibrillation, benzodiazepine use, and gait speed. Suggestive to highly suggestive evidence was found for that of midlife to late-life blood pressure, homocysteine, cerebrovascular diseases, hearing impairment, respiratory illness, anemia, smoking, alcohol consumption, diet, sleep, physical activity and social engagement. Among convincing evidence, Mendelian randomization studies verified causal relationships of education and plasma glucose with Alzheimer's disease.Limitations: Low quality of the studies included.Conclusions: Modifiable risk factors identified in this study, especially those with high-level evidence, should be considered in dementia prevention. Our results support a valuable rationale for future experimental designs to establish further evidence for the associations in larger populations. [ABSTRACT FROM AUTHOR]

Shift work is associated with susceptibility to several neuropsychiatric disorders. This study aims to investigate the effect of shift work on the incidence of neuropsychiatric disorders, and highlighting how individual variability may influence the association. UK Biobank participants with employment information were included. Cox survival was conducted in main and subgroup analyses. Correlation analyses explored the impact of shift work on brain structures, and mediation analyses were performed to elucidate the shared underlying mechanisms. Shift work tolerance was evaluated through survival analyses contrasting the risks associated with five neuropsychiatric disorders in shift versus non-shift workers across different demographic or occupational strata. The analysis encompassed 254,646 participants. Shift work was associated with higher risk of dementia (HR 1.29, 95 % CI 1.10–1.52), anxiety (1.08, 1.01–1.15), depression (1.29, 1.22–1.36), and sleep disorders (1.18, 1.09–1.28), but not stroke (p = 0.20). Shift work was correlated with decreasing volume of various brain regions, particularly in thalamus, lateral orbitofrontal, and middle temporal. Mediation analysis revealed that increased immune response and glucose levels are common pathways linking shift work to these disorders. We observed diversity in shift work tolerance across different individual characteristics, among which socioeconomic status and length of working hours were the most essential. Self-reported employment information may cause misclassification and recall bias. And since we focused on the middle-aged population, the conclusions may not be representative of younger or older populations. Our findings indicated the need to monitor shift worker health and provide personalized management to help adapt to shift work. • Shift work increases risks of dementia, anxiety, depression, and sleep disorders, probably via immune and glucose level. • Shift work was correlated with decreasing volume of various brain regions, particularly in thalamus, lateral orbitofrontal, and middle temporal. • Increasing immune reaction and glucose were the shared mechanisms than linking shift work to all four disorders. • Socioeconomic status and working hours were the most essential individual characteristics that contribute to shift work tolerance. [ABSTRACT FROM AUTHOR]

Studies have shown that multimorbidity may be associated with the Alzheimer's disease (AD) stages, but it has not been fully characterized in patients without dementia. A total of 1402 Han Chinese older adults without dementia from Chinese Alzheimer's Biomarker and LifestylE (CABLE) study were included and grouped according to their multimorbidity patterns, defined by the number of chronic disorders and cluster analysis. Multivariable linear regression models were used to detect the associations with AD-related cerebrospinal fluid (CSF) biomarkers. Multimorbidity and severe multimorbidity (≥4 chronic conditions) were significantly associated with CSF amyloid and tau levels (p FDR < 0.05). Metabolic patterns were significantly associated with higher levels of CSF Aβ40 (β = 0.159, p FDR = 0.036) and tau (P-tau: β = 0.132, p FDR = 0.035; T-tau: β = 0.126, p FDR = 0.035). The above associations were only significant in the cognitively normal (CN) group. Multimorbidity was associated with brain AD pathology before any symptomatic evidence of cognitive impairment. Identifying such high-risk groups might allow tailored interventions for AD prevention. [ABSTRACT FROM AUTHOR]

• Life-course risk for incident dementia was modulated by lung function. • Immunity, oxygen-carrying indices and specific metabolites are critical mediators. • Brain structures were substantially changed with poor lung function. • Monitoring lung function is of great significance for cognitive brain health. Whether lung function prospectively affects cognitive brain health independent of their overlapping factors remains largely unknown. This study aimed to investigate the longitudinal association between decreased lung function and cognitive brain health and to explore underlying biological and brain structural mechanisms. This population-based cohort included 43,1834 non-demented participants with spirometry from the UK Biobank. Cox proportional hazard models were fitted to estimate the risk of incident dementia for individuals with low lung function. Mediation models were regressed to explore the underlying mechanisms driven by inflammatory markers, oxygen-carrying indices, metabolites, and brain structures. During a follow-up of 3,736,181 person-years (mean follow-up 8.65 years), 5,622 participants (1.30 %) developed all-cause dementia, which consisted of 2,511 Alzheimer's dementia (AD) and 1,308 Vascular Dementia (VD) cases. Per unit decrease in lung function measure was each associated with increased risk for all-cause dementia (forced expiratory volume in 1 s [liter]: hazard ratio [HR, 95 %CI], 1.24 [1.14–1.34], P = 1.10 × 10-07; forced vital capacity [liter]: 1.16 [1.08–1.24], P = 2.04 × 10-05; peak expiratory flow [liter/min]: 1.0013 [1.0010–1.0017], P = 2.73 × 10-13). Low lung function generated similar hazard estimates for AD and VD risks. As underlying biological mechanisms, systematic inflammatory markers, oxygen-carrying indices, and specific metabolites mediated the effects of lung function on dementia risks. Besides, brain grey and white matter patterns mostly affected in dementia were substantially changed with lung function. Life-course risk for incident dementia was modulated by individual lung function. Maintaining optimal lung function is useful for healthy aging and dementia prevention. [ABSTRACT FROM AUTHOR]