Journal of Alzheimer's Disease - Volume 89, issue 4

Authors: Yang, Jingjing | Oveisgharan, Shahram | Liu, Xizhu | Wilson, Robert S. | Bennett, David A. | Buchman, Aron S.

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is a progressive disorder without a cure. Develop risk prediction models for detecting presymptomatic AD using non-cognitive measures is necessary to enable early interventions. Objective: Examine if non-cognitive metrics alone can be used to construct risk models to identify adults at risk for AD dementia and cognitive impairment. Methods: Clinical data from older adults without dementia from the Memory and Aging Project (MAP, n  = 1,179) and Religious Orders Study (ROS, n  = 1,103) were analyzed using Cox proportional hazard models to develop risk prediction models for AD dementia and cognitive impairment. Models using …only non-cognitive covariates were compared to models that added cognitive covariates. All models were trained in MAP, tested in ROS, and evaluated by the AUC of ROC curve. Results: Models based on non-cognitive covariates alone achieved AUC (0.800,0.785) for predicting AD dementia (3.5) years from baseline. Including additional cognitive covariates improved AUC to (0.916,0.881). A model with a single covariate of composite cognition score achieved AUC (0.905,0.863). Models based on non-cognitive covariates alone achieved AUC (0.717,0.714) for predicting cognitive impairment (3.5) years from baseline. Including additional cognitive covariates improved AUC to (0.783,0.770). A model with a single covariate of composite cognition score achieved AUC (0.754,0.730). Conclusion: Risk models based on non-cognitive metrics predict both AD dementia and cognitive impairment. However, non-cognitive covariates do not provide incremental predictivity for models that include cognitive metrics in predicting AD dementia, but do in models predicting cognitive impairment. Further improved risk prediction models for cognitive impairment are needed. Show more

Keywords: Alzheimer’s disease, cognitive aging, cohort study, Cox proportional hazard model, mild cognitive impairment

DOI: 10.3233/JAD-220446

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1249-1262, 2022

Authors: Shkirkova, Kristina | Lamorie-Foote, Krista | Zhang, Nathan | Li, Andrew | Diaz, Arnold | Liu, Qinghai | Thorwald, Max A. | Godoy-Lugo, Jose A. | Ge, Brandon | D’Agostino, Carla | Zhang, Zijiao | Mack, Wendy J. | Sioutas, Constantinos | Finch, Caleb E. | Mack, William J. | Zhang, Hongqiao

Article Type: Research Article

Abstract: Background: Air pollution particulate matter (PM) is strongly associated with risks of accelerated cognitive decline, dementia and Alzheimer’s disease. Ambient PM batches have variable neurotoxicity by collection site and season, which limits replicability of findings within and between research groups for analysis of mechanisms and interventions. Diesel exhaust particles (DEP) offer a replicable model that we define in further detail. Objective: Define dose- and time course neurotoxic responses of mice to DEP from the National Institute of Science and Technology (NIST) for neurotoxic responses shared by DEP and ambient PM. Methods: For dose-response, adult C57BL/6 male …mice were exposed to 0, 25, 50, and 100μg/m3 of re-aerosolized DEP (NIST SRM 2975) for 5 h. Then, mice were exposed to 100μg/m3 DEP for 5, 100, and 200 h and assayed for amyloid-β peptides, inflammation, oxidative damage, and microglial activity and morphology. Results: DEP exposure at 100μg/m3 for 5 h, but not lower doses, caused oxidative damage, complement and microglia activation in cerebral cortex and corpus callosum. Longer DEP exposure for 8 weeks/200 h caused further oxidative damage, increased soluble Aβ, white matter injury, and microglial soma enlargement that differed by cortical layer. Conclusion: Exposure to 100μg/m3 DEP NIST SRM 2975 caused robust neurotoxic responses that are shared with prior studies using DEP or ambient PM0.2. DEP provides a replicable model to study neurotoxic mechanisms of ambient PM and interventions relevant to cognitive decline and dementia. Show more

Keywords: Air pollution, Alzheimer’s disease, brain, dementia, diesel exhaust particle, neurotoxicity

DOI: 10.3233/JAD-220493

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1263-1278, 2022

Authors: Kanagasingam, Shalini | von Ruhland, Christopher | Welbury, Richard | Singhrao, Sim K.

Article Type: Research Article

Abstract: Background: Tau is an established substrate for gingipains secreted by Porphyromonas gingivalis . Hyperphosphorylation of tau and neurofibrillary tangle (NFT) formation is a defining lesion of Alzheimer’s disease (AD) where NFT distribution is related to Braak stage and disease severity. Objective: To assess gingipains’-fragmented tau peptides for their antimicrobial properties and for the likelihood of paired helical/straight filament (PHF/SF) formation with implications for the NFT lesion. Methods: Seven non-phosphorylated (A-G) and three phosphorylated (A-C) tau peptides, were tested for antimicrobial properties against P. gingivalis . Polarizing light properties were determined using Congo Red staining. Secondary and …tertiary structures of peptides B-F were determined using transmission electron microscopy (TEM) and circular dichroism (CD) was undertaken for the soluble peptides A in phosphorylated and non-phosphorylated states. Results: Phosphorylated tau peptide A displayed a significant effect against planktonic P. gingivalis . The CD results demonstrated that both peptides A, in phosphorylated and non-phosphorylated states, in aqueous solution, adopted mainly β-type structures. Non-phosphorylated peptides B-F and phosphorylated peptides B-C were insoluble and fibrillar under the TEM. The secondary and tertiary structures of the non-phosphorylated peptide B demonstrated fewer helical twists, whereas peptide C displayed significantly more helical twists along the whole fiber(s) length following its phosphorylation. Conclusion: Phosphorylated peptide A reduced P. gingivalis viability. CD spectroscopy demonstrated the phosphorylated and the non-phosphorylated peptide A predominantly formed from β-sheet structures in aqueous solution with potential antimicrobial activity. Phosphorylation of tau peptides physically changed their tertiary structure into PHFs with potential for self-aggregation and binding to the NFT lesion. Show more

Keywords: Antimicrobial, β-sheet, birefringence, gingipains, neurofibrillary tangles, Porphyromonas gingivalis, tau

DOI: 10.3233/JAD-220486

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1279-1291, 2022

Authors: Gentreau, Mélissa | Reynes, Christelle | Sabatier, Robert | Maller, Jerome J. | Meslin, Chantal | Deverdun, Jeremy | Le Bars, Emmanuelle | Raymond, Michel | Berticat, Claire | Artero, Sylvaine

Article Type: Research Article

Abstract: Background: Glucometabolic changes, such as high glycemic load (GL) diet and insulin resistance (IR), are potential risk factor of Alzheimer’s disease (AD). Yet, the effect of these factors on brain alterations that contribute to AD pathology has not been clearly demonstrated. Objective: We aimed to assess the relationship of GL and IR with gray matter volumes involved in prodromal dementia. Methods: GL and Triglyceride-Glucose (TyG) index, an IR surrogate marker, were calculated in 497 participants who underwent magnetic resonance imaging (MRI). The gray matter volumes most related to prodromal dementia/mild cognitive impairment (diagnosed in 18/158 participants …during the 7-year follow-up) were identified using a data-driven machine learning algorithm. Results: Higher GL diet was associated with reduced amygdala volume. The TyG index was negatively associated with the hippocampus, amygdala, and putamen volumes. Conclusion: These results suggest that GL and IR are associated with lower gray matter volumes in brain regions involved in AD pathology. Show more

Keywords: Amygdala, dementia, glycemic load, hippocampus, insulin resistance, magnetic resonance imaging, putamen

DOI: 10.3233/JAD-220490

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1293-1302, 2022

Authors: Michopoulou, Sofia | Prosser, Angus | Kipps, Christopher | Dickson, John | Guy, Matthew | Teeling, Jessica

Article Type: Research Article

Abstract: Background: Neuroinflammation is an integral part of Alzheimer’s disease (AD) pathology. Inflammatory mediators can exacerbate the production of amyloid-β (Aβ), the propagation of tau pathology and neuronal loss. Objective: To evaluate the relationship between inflammation markers and established markers of AD in a mixed memory clinic cohort. Methods: 105 cerebrospinal fluid (CSF) samples from a clinical cohort under investigation for cognitive complaints were analyzed. Levels of Aβ42 , total tau, and phosphorylated tau were measured as part of the clinical pathway. Analysis of inflammation markers in CSF samples was performed using multiplex immune assays. Participants were …grouped according to their Aβ, tau, and neurodegeneration status and the Paris-Lille-Montpellier (PLM) scale was used to assess the likelihood of AD. Results: From 102 inflammatory markers analyzed, 19 and 23 markers were significantly associated with CSF total tau and phosphorylated tau levels respectively (p  < 0.001), while none were associated with Aβ42 . The CSF concentrations of 4 inflammation markers were markedly elevated with increasing PLM class indicating increased likelihood of AD (p  < 0.001). Adenosine deaminase, an enzyme involved in sleep homeostasis, was the single best predictor of high likelihood of AD (AUROC 0.788). Functional pathway analysis demonstrated a widespread role for inflammation in neurodegeneration, with certain pathways explaining over 30% of the variability in tau values. Conclusion: CSF inflammation markers increase significantly with tau and neurodegeneration, but not with Aβ in this mixed memory clinic cohort. Thus, such markers could become useful for the clinical diagnosis of neurodegenerative disorders alongside the established Aβ and tau measures. Show more

Keywords: Amyloid-β, dementia, inflammation, tau protein

DOI: 10.3233/JAD-220523

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1303-1314, 2022

Authors: Li, Sijie | Liu, Bian | Li, Qing-hao | Zhang, Yan | Zhang, Haihua | Gao, Shan | Wang, Longcai | Wang, Tao | Han, Zhifa | Liu, Guiyou | Wang, Kun

Article Type: Research Article

Abstract: Background: Until now, both cross-sectional and longitudinal studies have identified controversial findings about the association between daytime napping and Alzheimer’s disease (AD) or cognitive decline. Therefore, it remains unclear about the causal association between daytime napping and AD or cognitive decline. Objective: We aim to investigate the causal association between daytime napping and AD. Methods: Here, we conduct a bidirectional Mendelian randomization (MR) analysis to investigate the causal association between daytime napping and AD using large-scale GWAS datasets from daytime napping including 452,633 individuals of European ancestry and AD including 35,274 AD and 59,163 controls of …European ancestry. A total of five MR methods are selected including inverse-variance weighted (IVW), weighted median, MR-Egger, MR-PRESSO, and contamination mixture method. Results: MR analysis highlights significant causal association of AD with daytime napping using IVW (beta = -0.006, 95% CI [–0.009, –0.002], p  = 2.00E-03), but no significant causal association of daytime napping with AD using IVW (OR = 0.76, 95% CI 0.53-1.10, p  = 1.40E-01). Conclusion: Our bidirectional MR analysis demonstrates the causal effect of AD on daytime napping. However, there is no causal effect of daytime napping on AD. Our current findings are consistent with recent evidence from other MR studies that highlight little evidence supporting a causal effect of sleep traits on AD and support the causal effect of AD on sleep traits. Show more

Keywords: Alzheimer’s disease, daytime napping, genome-wide association study, Mendelian randomization

DOI: 10.3233/JAD-220497

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1315-1322, 2022

Authors: Pang, Ting | Chong, Eddie Jun Yi | Wong, Zi Xuen | Chew, Kimberly Ann | Venketasubramanian, Narayanaswamy | Chen, Christopher | Xu, Xin

Article Type: Research Article

Abstract: Background: The Quick Dementia Rating System (QDRS) is a brief and rapid tool that can be administered by an informant without the need for a trained assessor. Objective: Our objective was to examine the validity, reliability, and cost-effectiveness of the informant QDRS in a Singapore memory clinic sample. Methods: We assessed a total of 177 older adults, among whom, 32 had no cognitive impairment (NCI), 61 had mild cognitive impairment (MCI), and 84 had dementia. Elderly underwent 1) the informant QDRS, 2) the Clinical Dementia Rating (CDR) as the gold standard diagnosis, 3) the Mini-Mental State …Examination (MMSE), and 4) the Ascertain Dementia 8 (AD8) as comparisons to the QDRS. The extent to which the QDRS may reduce the recruitment cost (time) of clinical trials was also calculated. Results: The QDRS had excellent internal consistency (Cronbach alpha = 0.939). It correlated highly with the CDR-global (R = 0.897), CDR Sum-of-Boxes (R = 0.915), MMSE (R = –0.848), and the AD8 (R = 0.747), showing good concurrent validity. With an optimal cut-off of 1.5 for MCI (sensitivity 85.2%, specificity 96.3%) and 6 for dementia (sensitivity 90.1%, specificity 89.2%), the QDRS achieved a higher overall accuracy of 85.0%, as compared to MMSE (71.2%) and AD8 (73.4%). A simulated clinical trial recruitment scenario demonstrated that pre-screening with the QDRS followed by a confirmatory CDR would reduce the time needed to identify NCI subjects by 23.3% and MCI subjects by 75.3%. Conclusion: The QDRS is a reliable cognitive impairment screening tool which is suitable for informant-administration, especially for identification of MCI. Show more

Keywords: Cost-effectiveness, discriminant utility, mild cognitive impairment, Quick Dementia Rating System, staging tool

DOI: 10.3233/JAD-220520

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1323-1330, 2022

Authors: Bardenheier, Barbara Helen | Resnik, Linda J. | Jutkowitz, Eric | Gravenstein, Stefan

Article Type: Research Article

Abstract: Background: To reduce the increasing societal and financial burden of Alzheimer’s disease and related dementias (ADRD), prevention is critical. Even small improvements of the modifiable dementia risk factors on the individual level have the potential to lead to a substantial reduction of dementia cases at the population level. Objective: To determine if pattern(s) of functional decline in midlife associate with late-onset ADRD years later. Methods: Using a longitudinal study of adults aged 51–59 years in 1998 without symptoms of ADRD by 2002 and followed them from 2002 to 2016 (n  = 5404). The outcome was incident ADRD …identified by the Lange-Weir algorithm, death, or alive with no ADRD. We used cluster analysis to identify patterns of functional impairment at baseline and multinomial regression to assess their association with future ADRD. Results: Three groups of adults with differing patterns of functional impairment were at greater risk of future ADRD. Difficulty with climbing one flight of stairs was observed in all adults in two of these groups. In the third group, 100% had difficulty with lifting 10 pounds and pushing or pulling a large object, but only one-fourth had difficulty in climbing stairs. Conclusion: Results imply that improved large muscle strength could decrease future risk of ADRD. If confirmed in other studies, screening for four self-reported measures of function among adults in midlife may be used for targeted interventions. Show more

Keywords: Alzheimer’s disease and related dementias, Health and Retirement Study, late midlife, physical function limitation

DOI: 10.3233/JAD-220573

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1331-1338, 2022

Authors: Kurasz, Andrea M. | De Wit, Liselotte | Smith, Glenn E. | Armstrong, Melissa J.

Article Type: Research Article

Abstract: Background: Survival and associated clinical and pathological characteristics in Lewy body disease (LBD)-related dementias are understudied. Available studies focus primarily on white non-Hispanic samples. Objective: We investigated demographic, clinical, and pathological correlates of survival by race and ethnicity in an autopsy-confirmed cohort of LBD cases. Methods: Using National Alzheimer’s Coordinating Center data, we selected participants who self-identified as Black, Hispanic, or white who had neuropathological assessments showing transitional or diffuse LBD pathology. We used Kruskal-Wallis and Pearson χ2 analyses to investigate group differences in demographic and presenting clinical and pathological characteristics. We used linear regressions …to identify predictors of survival with sex, age at symptom onset, education, ethnoracial status, LBD pathology type, and Braak tangle stage included in the model. Results: Data from 1,441 white, 60 Black, and 54 Hispanic participants were available for analysis. Hispanics were more likely to have transitional LBD pathology and had a longer survival than white and Black participants. After controlling for demographic and pathological variables, length of survival did not differ between Hispanics and Black or white participants. Additional key findings demonstrated discrepancies between clinical diagnoses received at last visit and pathological findings, particularly among Black participants. Conclusion: LBD survival differences by race and ethnicity can be accounted for by LBD pathology type and co-occurring Alzheimer’s disease pathology. The discrepancies between clinical diagnoses and pathological findings raise the concern that dementia with Lewy bodies is underdiagnosed in NACC, especially for Black older adults. Show more

Keywords: Cognitive dysfunction, dementia, ethnicity, Lewy body disease, neuropathology, racial groups

DOI: 10.3233/JAD-220297

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1339-1349, 2022

Authors: Wawrziczny, Emilie | Picard, Sandrine | Buquet, Amandine | Traversac, Elodie | Puisieux, François | Pasquier, Florence | Huvent-Grelle, Dominique | Doba, Karyn

Article Type: Research Article

Abstract: Background: Dementia has a negative impact on the quality of life of the person with dementia and their spouse caregivers, as well as on the couple’s relationship, which can lead to high levels of distress for both partners. Hypnosis has been shown to be effective in managing distress and increasing the quality of the relationship. Objective: The aim was to develop a standardized hypnosis intervention for couples confronted with Alzheimer’s disease and evaluate its feasibility, acceptability, and helpfulness in managing the distress of both partners and increasing the quality of the relationship. Methods: In a single-arm …study, sixteen couples received the 8-week intervention. Qualitative and quantitative assessments were conducted pre- and post-intervention as well as three months after. Results: 88.9% of couples (n  = 16) of the final sample (n  = 18) completed the intervention. Despite the negative representations of hypnosis, several factors led couples to accept to participate in this study: positive expectations, professional endorsement, medical application, non-drug approach, home-based, free, flexible, and couple-based intervention. The results showed a significant decrease in distress for both partners. These effects were maintained three months after the intervention. Couples felt more relaxed, had fewer negative emotions, accepted difficulties more easily, were more patient, and reported better communication and more affection in the relationship. Conclusion: Overall, this pilot study shows the feasibility and acceptability of hypnosis with couples confronted with Alzheimer’s disease. Although measures of the preliminary pre- and post-intervention effects are encouraging, confirmatory testing with a randomized controlled trial is needed. Show more

Keywords: Alzheimer’s disease, couple, distress, hypnosis

DOI: 10.3233/JAD-220430

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1351-1366, 2022

Authors: Zawar, Ifrah | Mattos, Meghan K. | Manning, Carol | Quigg, Mark

Article Type: Research Article

Abstract: Background: While sleep disturbances appear to be risk factors in Alzheimer’s disease (AD) progression, information such as the prevalence across dementia severity and the influence on the trajectory of cognitive decline is unclear. Objective: We evaluate the hypotheses that the prevalence of insomnia differs by cognitive impairment, that sleep disturbances track with AD biomarkers, and that longitudinal changes in sleep disorders affect cognition. Methods: We used the National Alzheimer’s Coordinating Center Database to determine the prevalence of clinician-identified insomnia and nighttime behaviors in normal, mild cognitive impairment (MCI), and demented individuals. We evaluated mean Montreal Cognitive …Assessment (MoCA) scores, hippocampal volumes (HV), and CSF phosphorylated tau:amyloid-β ratios at first visit using analysis of variance with age as a covariate. In longitudinal evaluations, we assessed changes in MoCA scores and HV in insomnia and nighttime behaviors between the first and last visits. Results: Prevalence of insomnia was 14%, 16%, and 11% for normal, MCI, and dementia groups. Prevalence of nighttime behaviors was 14%, 21%, and 29% respectively. Insomnia patients had higher MoCA scores, larger HV, and lower pTauBeta than individuals without insomnia, indicating less neurodegeneration. In contrast, nighttime behaviors were associated with worse cognition, smaller HV, and higher pTauBeta. Similar findings were seen between longitudinal associations of sleep disorders and cognition and HV. Conclusion: Our findings suggest that insomnia is unreliably recognized in patients with cognitive impairment. Nighttime behaviors may better indicate the presence of sleep disturbances and have diagnostic specificity in AD over insomnia. Show more

Keywords: Dementia, hippocampus, insomnia, sleep, sleep insufficiency

DOI: 10.3233/JAD-220664

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1367-1374, 2022

Authors: Perales-Puchalt, Jaime | Townley, Ryan | Niedens, Michelle | Vidoni, Eric D. | Greiner, K. Allen | Zufer, Tahira | Schwasinger-Schmidt, Tiffany | McGee, Jerrihlyn L. | Arreaza, Hector | Burns, Jeffrey M.

Article Type: Research Article

Abstract: Background: Optimal care can improve lives of families with dementia but remains under-implemented. Most healthcare professional training is in person, time-intensive, and does not focus on key aspects such as early detection, and cultural competency. Objective: We explored the acceptability and preliminary effectiveness of a training, The Dementia Update Course, which addressed these issues. We hypothesized that the training would lead to increased levels of perceived dementia care competency among key healthcare workers, namely primary care providers (PCPs) and health navigators (HNs). Methods: We conducted pre-post training assessments among 22 PCPs and 32 HNs. The 6.5-h …training was remote, and included didactic lectures, case discussion techniques, and materials on dementia detection and care. Outcomes included two 5-point Likert scales on acceptability, eleven on perceived dementia care competency, and the three subscales of the General Practitioners Confidence and Attitude Scale for Dementia. We used paired samples t -tests to assess the mean differences in all preliminary effectiveness outcomes. Results: The training included 28.6% of PCPs and 15.6% of HNs that self-identified as non-White or Latino and 45.5% of PCPs and 21.9% of HNs who served in rural areas. PCPs (84.2%) and HNs (91.7%) reported a high likelihood to recommend the training and high satisfaction. Most preliminary effectiveness outcomes analyzed among PCPs (11/14) and all among HNs (8/8) experienced an improvement from pre- to post-training (p  < 0.05). Conclusion: A relatively brief, remote, and inclusive dementia training was associated with high levels of acceptability and improvements in perceived dementia care competency among PCPs and HNs. Show more

Keywords: Attitude of health personnel, dementia, education, healthcare professionals

DOI: 10.3233/JAD-220235

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1375-1384, 2022

Authors: Weible, Aldis P. | Wehr, Michael

Article Type: Research Article

Abstract: Background: Effective treatment of Alzheimer’s disease (AD) will hinge on early detection. This has led to the search for early biomarkers that use non-invasive testing. One possible early biomarker is auditory temporal processing deficits, which reflect central auditory pathway dysfunction and precede cognitive and memory declines in AD. Gap detection is a measure of auditory temporal processing, is impaired in human AD, and is also impaired in the 5XFAD mouse model of AD. Gap detection deficits appear as early as postnatal day 60 in 5XFAD mice, months before cognitive deficits or cell death, supporting gap detection as an early biomarker. …However, it remains unclear how gap detection deficits relate to the progression of amyloid pathology in the auditory system. Objective: To determine the progression of amyloid pathology throughout the central auditory system and across age in 5XFAD mice. Methods: We quantified intracellular and extracellular antibody labelling of Aβ42 in 6 regions of the central auditory system from p14 to p150. Results: Pathology appeared first in primary auditory cortex (A1) as intracellular accumulation of Aβ42 in layer 5 pyramidal neurons by age p21. Extracellular plaques appeared later, by age p90, in A1, medial geniculate body, and inferior colliculus. Auditory brainstem structures showed minimal amyloid pathology. We also observed pathology in the caudal pontine reticular nucleus, a brainstem structure that is outside of the central auditory pathway but which is involved in the acoustic startle reflex. Conclusion: These results suggest that Aβ42 accumulation, but not plaques, may impair gap detection. Show more

Keywords: Aβ42, Alzheimer’s disease, biomarker, gap detection, inferior colliculus, medial geniculate body, primary auditory cortex

DOI: 10.3233/JAD-220538

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1385-1402, 2022

Authors: Nyholm, Ebba | Torkpoor, Rozita | Frölich, Kristin | Londos, Elisabet | Cicognola, Claudia

Article Type: Research Article

Abstract: Background: People with a migration background are underrepresented in dementia research and disfavored in assessment and treatment, and many foreign-born individuals with dementia remain undiagnosed. Objective: The aim of this study was to examine whether there is inequality in the clinical assessment of dementia between native and foreign-born individuals in Sweden. Methods: Information was gathered retrospectively from a cohort of 91 native and 36 foreign-born patients attending four memory clinics in Skåne, Sweden. Data included information on cognitive test results, cerebrospinal fluid biomarkers, scores at structural imaging scales of global cortical atrophy (GCA), medial temporal lobe …atrophy (MTA) and the Fazekas scale, laboratory measures of thyroid-stimulating hormone, calcium, albumin, homocysteine, hemoglobin, cobalamin (vitamin B12), and folate (vitamin B9), contact with health care, and treatment. Results: Foreign-born patients had lower educational level and scored lower on Mini-Mental State Examination and Clock Drawing Test (p  < 0.001–0.011). Relatives initiated contact with health care to a higher extent in the foreign-born group (p  = 0.031). Foreign-born patients had less white matter lesions (p  = 0.018). Additionally, Alzheimer’s disease (AD) biomarkers were significantly less used in foreign-born patients to support an AD diagnosis (p  = 0.001). No significant differences were found for scores on GCA and MTA, laboratory measures, or initiated treatment. Conclusion: Although native and foreign-born patients were predominantly homogenous regarding examined variables, differences in the diagnostic process and underlying biological correlates of dementia exist and need to be further investigated in a larger sample. Show more

Keywords: Alzheimer’s disease, cognitive impairment, dementia, health care inequalities, immigrants

DOI: 10.3233/JAD-220177

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1403-1412, 2022

Authors: Ohno, Kazuya | Abdelhamid, Mona | Zhou, Chunyu | Jung, Cha-Gyun | Michikawa, Makoto

Article Type: Research Article

Abstract: Background: We previously reported the effects of a probiotic strain, Bifidobacterium breve MCC1274, in improving cognitive function in preclinical and clinical studies. Recently, we demonstrated that supplementation of this strain led to decreased amyloid-β production, attenuated microglial activation, and suppressed inflammation reaction in the brain of APP knock-in (App NL  - G  - F ) mice. Objective: In this study, we investigated the plasma metabolites to reveal the mechanism of action of this probiotic strain in this Alzheimer’s disease (AD)-like model. Methods: Three-month-old mice were orally supplemented with B. breve MCC1274 or saline for four …months and their plasma metabolites were comprehensively analyzed using CE-FTMS and LC-TOFMS. Results: Principal component analysis showed a significant difference in the plasma metabolites between the probiotic and control groups (PERMANOVA, p  = 0.03). The levels of soy isoflavones (e.g., genistein) and indole derivatives of tryptophan (e.g., 5-methoxyindoleacetic acid), metabolites with potent anti-oxidative activities were significantly increased in the probiotic group. Moreover, there were increased levels of glutathione-related metabolites (e.g., glutathione (GSSG)_divalent, ophthalmic acid) and TCA cycle-related metabolites (e.g., 2-Oxoglutaric acid, succinic acid levels) in the probiotic group. Similar alternations were observed in the wild-type mice by the probiotic supplementation. Conclusion: These results suggest that the supplementation of B. breve MCC1274 enhanced the bioavailability of potential anti-oxidative metabolites from the gut and addressed critical gaps in our understanding of the gut-brain axis underlying the mechanisms of the probiotic action of this strain in the improvement of cognitive function. Show more

Keywords: Alzheimer’s disease, anti-oxidative activity, Bifidobacterium breve MCC1274, glutathione, soy isoflavones, TCA cycle, tryptophan derivative

DOI: 10.3233/JAD-220479

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1413-1425, 2022

Authors: Comon, Martin | Rouch, Isabelle | Edjolo, Arlette | Padovan, Catherine | Krolak-Salmon, Pierre | Dorey, Jean-Michel

Article Type: Research Article

Abstract: Background: Facial emotion recognition (FER) and gaze direction (GD) identification are core components of social cognition, possibly impaired in many psychiatric or neurological conditions. Regarding Alzheimer’s disease (AD), current knowledge is controversial. Objective: The aim of this study was to explore FER and GD identification in mild AD compared to healthy controls. Methods: 180 participants with mild AD drawn from the PACO study and 74 healthy elderly controls were enrolled. Participants were asked to complete three socio-cognitive tasks: face sex identification, recognition of facial emotions (fear, happiness, anger, disgust) expressed at different intensities, and GD discrimination. …Multivariate analyses were conducted to compare AD participants and healthy controls. Results: Sex recognition was preserved. GD determination for subtle deviations was impaired in AD. Recognition of prototypically expressed facial emotions was preserved while recognition of degraded facial emotions was impacted in AD participants compared to controls. Use of multivariate analysis suggested significant alteration of low-expressed fear and disgust recognition in the AD group. Conclusion: Our results showed emotion recognition and GD identification in patients with early-stage AD compared to elderly controls. These impairments could be the object of specific therapeutic interventions such as social cognition remediation or raising awareness of primary caregivers to improve the quality of life of patients with early AD. Show more

Keywords: Alzheimer’s disease, elderly, facial emotion recognition, social cognition

DOI: 10.3233/JAD-220401

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1427-1437, 2022

Authors: de Oliveira Otto, Marcia C. | Li, Xinmin S. | Wang, Zeneng | Siscovick, David S. | Newman, Anne B. | Lai, Heidi Tsz Mung | Nemet, Ina | Lee, Yujin | Wang, Meng | Fretts, Amanda | Lemaitre, Rozenn N. | Tang, W.H. Wilson | Lopez, Oscar | Hazen, Stanley L. | Mozaffarian, Dariush

Article Type: Research Article

Abstract: Background: Animal studies suggest that gut microbiome metabolites such as trimethylamine N-oxide (TMAO) may influence cognitive function and dementia risk. However potential health effects of TMAO and related metabolites remain unclear. Objective: We examined prospective associations of TMAO, γ -butyrobetaine, crotonobetaine, carnitine, choline, and betaine with risk of cognitive impairment and dementia among older adults aged 65 years and older in the Cardiovascular Health Study (CHS). Methods: TMAO and metabolites were measured in stored plasma specimens collected at baseline. Incident cognitive impairment was assessed using the 100-point Modified Mini-Mental State Examination administered serially up to 7 …times. Clinical dementia was identified using neuropsychological tests adjudicated by CHS Cognition Study investigators, and by ICD-9 codes from linked Medicare data. Associations of each metabolite with cognitive outcomes were assessed using Cox proportional hazards models. Results: Over a median of 13 years of follow-up, 529 cases of cognitive impairment, and 522 of dementia were identified. After multivariable adjustment for relevant risk factors, no associations were seen with TMAO, carnitine, choline, or betaine. In contrast, higher crotonobetaine was associated with 20–32% higher risk of cognitive impairment and dementia per interquintile range (IQR), while γ -butyrobetaine was associated with ∼25% lower risk of the same cognitive outcomes per IQR.∥ Conclusion: These findings suggest that γ -butyrobetaine, crotonobetaine, two gut microbe and host metabolites, are associated with risk of cognitive impairment and dementia. Our results indicate a need for mechanistic studies evaluating potential effects of these metabolites, and their interconversion on brain health, especially later in life. Show more

Keywords: Aging, cognition, dementia, diet, gut metabolites

DOI: 10.3233/JAD-220477

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1439-1452, 2022

Authors: Gong, Xianmin | Shi, Lin | Wu, Yuanyuan | Luo, Yishan | Kwok, Timothy

Article Type: Research Article

Abstract: Background: The effects of B vitamins on mild cognitive impairment (MCI) patients’ cognition have been mixed, suggesting the existence of moderating factors. Objective: A post hoc analysis of a negative B vitamin trial was performed to examine the potential modulating effect of regional brain atrophy on the cognitive response to B vitamins in MCI patients. Methods: In the 24-month randomized trial, 279 MCI outpatients took 500μ #x03BC;g methylcobalamin and 400μ #x03BC;g folic acid once per day or placebo tablets once per day. Sixty-four aspirin users were excluded from analysis as aspirin use has been found …to have significant negative interaction effects. Subjects were followed up at months 12 and 24. The primary cognitive outcome was clinical dementia rating scale sum of boxes (CDR_SOB). In a subgroup of 83 subjects, MRI brain scans were performed at baseline to estimate regional brain atrophy ratios. Results: Among the trial subjects who had MRI data, B vitamin supplementation had no significant effect on CDR_SOB, despite having significant homocysteine lowering effects. The atrophy ratio of the left frontal lobe significantly moderated the effect of B vitamin supplementation on CDR_SOB, after adjusting for confounders, in that B vitamin supplementation was associated with lower CDR_SOB scores (i.e., better cognitive function) at the 24th month among those patients with above median atrophy ratios, but not among those with lower atrophy ratios, in the left frontal lobe. Conclusion: B vitamins may be more effective in slowing down cognitive decline in MCI patients with atrophy in the left frontal lobe. Show more

Keywords: B vitamins, brain atrophy, folate, homocysteine, mild cognitive impairment Clinical trial registration: Centre for Clinical Research and Biostatistics (CCRB) Clinical Trials Registry: CUHK_CCT00373

DOI: 10.3233/JAD-220685

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1453-1461, 2022

Authors: Jaakkimainen, Liisa | Duchen, Raquel | Lix, Lisa | Al-Azazi, Saeed | Yu, Bing | Butt, Debra | Park, Su-Bin | Widdifield, Jessica

Article Type: Research Article

Abstract: Background: Early onset dementia (EOD) occurs when symptoms of dementia begin between 45 to 64 years of age. Objective: We developed and validated health administrative data algorithms for EOD and compared demographic characteristics and presence of comorbid conditions amongst adults with EOD, late onset dementia (LOD) and adults with no dementia in Ontario, Canada. Methods: Patients aged 45 to 64 years identified as having EOD in their primary care electronic medical records had their records linked to provincial health administrative data. We compared several combinations of physician’s claims, hospitalizations, emergency department visits and prescriptions. Age-standardized incidence …and prevalence rates of EOD were estimated from 1996 to 2016. Results: The prevalence of EOD for adults aged 45 to 64 years in our primary care reference cohort was 0.12%. An algorithm of ≥1 hospitalization or ≥3 physician claims at least 30 days apart in a two-year period or ≥1 dementia medication had a sensitivity of 72.9% (64.5–81.3), specificity of 99.7% (99.7–99.8), positive predictive value (PPV) of 23.7% (19.1–28.3), and negative predictive value of 100.0%. Multivariate logistic regression found adults with EOD had increased odds ratios for several health conditions compared to LOD and no dementia populations. From 1996 to 2016, the age-adjusted incidence rate increased slightly (0.055 to 0.061 per 100 population) and the age-adjusted prevalence rate increased three-fold (0.11 to 0.32 per 100 population). Conclusion: While we developed a health administrative data algorithm for EOD with a reasonable sensitivity, its low PPV limits its ability to be used for population surveillance. Show more

Keywords: Administrative data, algorithm, early onset dementia, primary care electronic medical records

DOI: 10.3233/JAD-220384

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1463-1472, 2022

Authors: Hsu, Chun Liang | Falck, Ryan S. | Backhouse, Daniel | Chan, Patrick | Dao, Elizabeth | ten Brinke, Lisanne F. | Manor, Brad | Liu-Ambrose, Teresa

Article Type: Research Article

Abstract: Background: Poor sleep quality is common among older individuals with mild cognitive impairment (MCI) and may be a consequence of functional alterations in the brain; yet few studies have investigated the underlying neural correlates of actigraphy-measured sleep quality in this cohort. Objective: The objective of this study was to examine the relationship between brain networks and sleep quality measured by actigraphy. Methods: In this cross-sectional analysis, sleep efficiency and sleep fragmentation were estimated using Motionwatch8 (MW8) over a period of 14 days in 36 community-dwelling older adults with possible MCI aged 65–85 years. All 36 participants …underwent resting-state functional magnetic resonance imaging (fMRI) scanning. Independent associations between network connectivity and MW8 measures of sleep quality were determined using general linear modeling via FSL. Networks examined included the somatosensory network (SMN), frontoparietal network (FPN), and default mode network (DMN). Results: Across the 36 participants (mean age 71.8 years; SD = 5.2 years), mean Montreal Cognitive Assessment score was 22.5 (SD = 2.7) and Mini-Mental State Examination score was 28.3 (SD = 1.5). Mean sleep efficiency and fragmentation index was 80.1% (SD = 10.0) and 31.8 (SD = 10.4) respectively. Higher sleep fragmentation was significantly correlated with increased connectivity between the SMN and insula, the SMN and posterior cingulate, as well as FPN and primary motor area (FDR-corrected, p  < 0.004). Conclusion: Functional connectivity between brain regions involved in attentional and somatosensory processes may be associated with disrupted sleep in older adults with MCI. Show more

Keywords: Mild cognitive impairment, objective sleep quality, older adults, resting-state functional magnetic resonance imaging

DOI: 10.3233/JAD-220457

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1473-1482, 2022

Authors: Wright, Joy R. | Deen, Quazi Fahm E. | Stevenson, Anna | Telford-Cooke, Leolie L. | Parker, Craig | Martin-Ruiz, Carmen | Steinert, Joern R. | Kalaria, Raj N. | Mukaetova-Ladinska, Elizabeta B.

Article Type: Research Article

Abstract: Background: Myeloperoxidase (MPO), a neutrophil-derived pro-inflammatory protein, co-localizes with amyloid-β (Aβ) plaques in Alzheimer’s disease (AD). Anti-dementia treatment may facilitate efflux of Aβ and associated plaque proteins from the brain to the peripheral circulation, therefore providing potential biomarkers for the monitoring of donor response to drug treatment. Objective: We investigated the diagnostic utility of MPO as a biomarker of AD, and how anti-dementia treatment alters plasma MPO concentration. Methods: Thirty-two AD patients were recruited, and plasma collected pre-drug administration (baseline), and 1- and 6-months post-treatment. All patients received cholinesterase inhibitors (ChEIs). At baseline and 6 months, …patients underwent neuropsychological assessment. Forty-nine elderly healthy individuals with normal cognitive status served as controls. Plasma MPO concentration was measured by ELISA. Results: AD drug naïve patients had similar plasma MPO concentration to their control counterparts (p  > 0.05). Baseline MPO levels positively correlated with Neuropsychiatric Inventory score (r  = 0.5080; p  = 0.011) and carer distress (r  = 0.5022; p  = 0.012). Following 1-month ChEI treatment, 84.4% of AD patients exhibited increased plasma MPO levels (p  < 0.001), which decreased at 6 months (p  < 0.001). MPO concentration at 1 month was greatest in AD patients whose memory deteriorated during the study period (p  = 0.028), and for AD patients with deterioration in Cornell assessment score (p  = 0.044). Conclusion: Whereas baseline MPO levels did not differentiate between healthy and AD populations, baseline MPO positively correlated with initial Neuropsychiatric Inventory evaluation. Post-treatment, transient MPO upregulation in ChEI-treated patients may reflect worse therapeutic outcome. Further studies are required to assess the potential of plasma MPO as an AD therapeutic biomarker. Show more

Keywords: Alzheimer’s disease, biomarkers, cholinesterase inhibitors, inflammation, myeloperoxidase, plasma

DOI: 10.3233/JAD-220642

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1483-1492, 2022

Authors: Beheshti, Iman | Geddert, Natasha | Perron, Jarrad | Gupta, Vinay | Albensi, Benedict C. | Ko, Ji Hyun

Article Type: Research Article

Abstract: Background: We previously introduced a machine learning-based Alzheimer’s Disease Designation (MAD) framework for identifying AD-related metabolic patterns among neurodegenerative subjects. Objective: We sought to assess the efficiency of our MAD framework for tracing the longitudinal brain metabolic changes in the prodromal stage of AD. Methods: MAD produces subject scores using five different machine-learning algorithms, which include a general linear model (GLM), two different approaches of scaled subprofile modeling, and two different approaches of a support vector machine. We used our pre-trained MAD framework, which was trained based on metabolic brain features of 94 patients with AD …and 111 age-matched cognitively healthy (CH) individuals. The MAD framework was applied on longitudinal independent test sets including 54 CHs, 51 stable mild cognitive impairment (sMCI), and 39 prodromal AD (pAD) patients at the time of the clinical diagnosis of AD, and two years prior. Results: The GLM showed excellent performance with area under curve (AUC) of 0.96 in distinguishing sMCI from pAD patients at two years prior to the time of the clinical diagnosis of AD while other methods showed moderate performance (AUC: 0.7–0.8). Significant annual increment of MAD scores were identified using all five algorithms in pAD especially when it got closer to the time of diagnosis (p  < 0.001), but not in sMCI. The increased MAD scores were also significantly associated with cognitive decline measured by Mini-Mental State Examination in pAD (q  < 0.01). Conclusion: These results suggest that MAD may be a relevant tool for monitoring disease progression in the prodromal stage of AD. Show more

Keywords: Alzheimer’s disease, brain metabolism, FDG PET, machine learning

DOI: 10.3233/JAD-220585

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1493-1502, 2022

Authors: George, Daniel R.

Article Type: Book Review

DOI: 10.3233/JAD-220791

Citation: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1503-1505, 2022