We comprehensively summarized the cohort evidence to date on adult-onset hearing loss as risk factor for incident cognitive impairment and dementia, and examined the evidence for dose-response, risk for various dementia subtypes, and other moderators. Previous meta-analyses were less comprehensive. We included cohort studies with participants without dementia and with hearing assessments at baseline, minimum 2 years follow-up and incident cognitive outcomes. We used random-effect models and subgroup and meta-regression on moderator analyses. We identified fifty studies (N=1,548,754). Hearing loss (yes/no) was associated with incident dementia risk (HR=1.35 [95% CI = 1.26 - 1.45), mild cognitive impairment (MCI HR=1.29 [95% CI = 1.11 - 1.50]), cognitive decline not specified as MCI or dementia (HR=1.29 [95% CI = 1.17 - 1.42]), and Alzheimer's disease dementia (ADD, HR=1.56 [95% CI = 1.30 - 1.87]), but not with vascular dementia (HR, 1.30 [95% CI = 0.83 - 2.05]). Each 10-decibel worsening of hearing was associated with a 16% increase in dementia risk (95% CI = 1.07 - 1.27). The effect of hearing loss did not vary across potential moderators. Cohort studies consistently support that adult-onset hearing loss increases the risk of incident cognitive decline, dementia, MCI, and ADD.

Plasma extracellular vesicles (EVs) containing various molecules, including cytokines, can reflect the intracellular condition and participate in cell-to-cell signaling, thus emerging as biomarkers for Parkinson’s disease (PD). Inflammation may be a crucial risk factor for PD development and progression. The present study investigated the role of plasma EV cytokines as the biomarkers of PD. This cross-sectional study recruited 113 patients with PD, with mild to moderate stage disease, and 48 controls. Plasma EVs were isolated, and the levels of cytokines, including pro-interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β1, were evaluated. Patients with PD had significantly increased plasma EV pro-IL-1β and TNF-α levels compared with controls after adjustment for age and sex. Despite the lack of a significant association between plasma EV cytokines and motor symptom severity in patients with PD, cognitive dysfunction severity, assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment, was significantly associated with plasma EV pro-IL-1β, IL-6, IL-10, and TNF-α levels. This association was PD specific and not found in controls. Furthermore, patients with PD cognitive deficit (MMSE < 26) exhibited a distinguished EV cytokine profile compared to those without cognitive deficit. The findings support the concept of inflammatory pathogenesis in the development and progression of PD and indicate that plasma EV cytokines may serve as PD biomarkers in future.

Background: Age-related hearing loss and mild cognitive impairment (MCI) independently increase dementia risk. The Ageing and Cognitive Health Evaluation in Elders randomised controlled trial (RCT) found hearing aids reduce cognitive decline in high-risk older adults with poor hearing. Methods: This pilot RCT in London memory clinics randomised people with MCI (aged ≥55, untreated hearing loss defined as Pure Tone Average 0.5–4 KHz between 25–70 dB) into two groups. The intervention group received 4 sessions of hearing aid fitting and support. The control group received healthy ageing education and a GP letter recommending audiological referral. Both were followed for 6 months. Primary outcomes were recruitment (feasibility target: 50%; 95% CI: 39%–61%) and retention (feasibility target: 80%; 95% CI: 71%–89%); intervention completion (≥2 visits) and hearing aid use (acceptability target: 80%; 95% CI: 71%–89%) for the intervention group and 50% difference between arms (95% CI: 31%–69%). Secondary outcomes included hearing aid fitting, cognition and other measures. Results: From October 2018 to March 2020, 58 participants were recruited (29 per group, 95% [86%–99%]). Twenty-four participants were fitted with hearing aids in the intervention arm, and 6 in the control arm (difference: 62% [42%–82%]). At 6 months, retention was 81% [69%–90%]. Hearing intervention completion (≥2 visits) was achieved by 24 (83%). Daily hearing aid use was reported by 18 (75%) intervention versus 5 (22%) control participants, a difference of 53% [29%–77%]. Conclusion: Randomisation of people with MCI to a personalised hearing intervention versus control is feasible. These findings support proceeding to a fully-powered multicentre RCT.

People with adult-onset hearing loss (AoHL) are at increased dementia risk. In this study, we explore potential aetiological mechanisms by synthesising the evidence on the association between AoHL and neuropathological, cerebrospinal fluid (CSF), blood and imaging biomarkers of dementia. We systematically searched electronic databases from inception to 30 April 2024 for cross-sectional and longitudinal studies, including quantitative data on the association between AoHL and dementia biomarkers. Study quality was assessed with the Mixed Methods Appraisal Tool (MMAT). Sixty-six studies reporting 63 cross-sectional and 10 longitudinal analyses were included. Twenty-one studies met all MMAT quality criteria. We report a narrative synthesis due to the heterogeneity of the included studies. In CSF-based or blood-based assays or imaging, five out of six cross-sectional analyses found that AoHL was associated with elevated in vivo tau levels, whilst four out of 17 reported a link with elevated in vivo β-amyloid measures. One longitudinal analysis identified an association between AoHL and a steeper increase of CSF tau, but not Aβ₄₂, levels over time. Twenty-five out of 44 cross-sectional and six out of nine longitudinal analyses identified associations between AoHL and grey matter atrophy of the temporal regions, particularly the medial temporal lobe. Studies using other biomarkers had inconsistent findings. AoHL was usually associated with more temporal regions grey matter atrophy both cross-sectionally and longitudinally, and elevated in vivo tau but not β-amyloid. Increasing atrophy and higher tau, leading to decreased cognitive reserve may be how hearing loss increases dementia risk.

Objective: The Addenbrooke’s Cognitive Examination III (ACE-III) is a 100-points cognitive test used in detecting dementia in many countries. There has been no validation study of the ACE-III in patients with suspected dementia in a Taiwanese population, where the language is traditional Chinese. We aimed to culturally adapt and validate the ACE-III as a cognitive assessment tool for differentiating between people with and without dementia presenting to healthcare professionals in Taiwan with possible dementia. Methods: We culturally adapted the ACE-III for Taiwan (T-ACE-III) and tested it with consenting patients with suspected dementia in northern Taiwan who had been through the diagnostic process. We calculated receiver operating characteristic (ROC) curves to test the ability of the T-ACE-III to differentiate between dementia and non-dementia cases using clinician diagnosis as the gold standard. We generated the Youden Index to determine the best cut-off score. Results: We recruited 90 Taiwanese individuals aged 49–93 years: 24 males and 33 females had dementia and 12 males and 21 females did not. The area under the ROC curve was 0.99 for distinguishing dementia from non-dementia. The T-ACE-III had a sensitivity of 100% and specificity of 78.8% when the cut-off score was 86/87. With a cut-off value of 73/74, the specificity was 100.0%, and sensitivity 89.5%. The highest Youden Index was 0.895, indicating the best overall cut-off point to be 73/74. Conclusions: The T-ACE-III is an acceptable cognitive test with excellent psychometric properties for discriminating dementia from non-dementia in Taiwanese populations in memory clinic settings.

Modelling ability is one of the essential elements of the latest educational reforms, and Trends in International Mathematics and Science Study (TIMSS) is a curriculum-based assessment which allows educational systems worldwide to inspect the curricular influences. The aims of this study were to examine the role of modelling ability in the generalized Grade 8 (G8) curriculum via TIMSS 2011 and to compare the G8 students’ modelling ability among the four top-performing countries (i.e., Japan, Korea, Singapore, and Taiwan) in Asia before the latest educational reforms. This study developed Modelling Ability Analytic Index-TIMSS (MAAI-T) to analyse TIMSS 2011 G8 items. There are two dimensions of MAAI-T, stages of modelling process (i.e., selection, construction, validation, analysis and application, and deployment) and levels of model complexity (i.e., Levels 1 through 4, from single factor to extended relation). The findings showed: TIMSS 2011 G8 items centred on the stage of modelling selection, and analysis and application and mainly measured Level 3 (simple relation among factors). The highest-performing country (Singapore) demonstrated Level 3 in all stages and Level 4 of model selection and deployment; while the lowest-performing country (Korea) demonstrated Level 3 only in the stages of model selection, validation, and analysis and application.