Clinical diagnosis of Alzheimer's disease and other dementias in a population survey. Agreement and causes of disagreement in applying Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, Criteria

New cyclophilin D inhibitor rescues mitochondrial and cognitive function in Alzheimer's disease

Mitochondrial dysfunction is an early pathological feature of Alzheimer disease and plays a crucial role in the development and progression of Alzheimer's disease. Strategies to rescue mitochondrial function and cognition remain to be explored. Cyclophilin D (CypD), the peptidylprolyl isomerase F (PPIase), is a key component in opening the mitochondrial membrane permeability transition pore, leading to mitochondrial dysfunction and cell death. Blocking membrane permeability transition pore opening by inhibiting CypD activity is a promising therapeutic approach for Alzheimer's disease. However, there is currently no effective CypD inhibitor for Alzheimer's disease, with previous candidates demonstrating high toxicity, poor ability to cross the blood-brain barrier, compromised biocompatibility and low selectivity. Here, we report a new class of non-toxic and biocompatible CypD inhibitor, ebselen, using a conventional PPIase assay to screen a library of ∼2000 FDA-approved drugs with crystallographic analysis of the CypD-ebselen crystal structure (PDB code: 8EJX). More importantly, we assessed the effects of genetic and pharmacological blockade of CypD on Alzheimer's disease mitochondrial and glycolytic bioenergetics in Alzheimer's disease-derived mitochondrial cybrid cells, an ex vivo human sporadic Alzheimer's disease mitochondrial model, and on synaptic function, inflammatory response and learning and memory in Alzheimer's disease mouse models. Inhibition of CypD by ebselen protects against sporadic Alzheimer's disease- and amyloid-β-induced mitochondrial and glycolytic perturbation, synaptic and cognitive dysfunction, together with suppressing neuroinflammation in the brain of Alzheimer's disease mouse models, which is linked to CypD-related membrane permeability transition pore formation. Thus, CypD inhibitors have the potential to slow the progression of neurodegenerative diseases, including Alzheimer's disease, by boosting mitochondrial bioenergetics and improving synaptic and cognitive function.

A survey on clinical natural language processing in the United Kingdom from 2007 to 2022

Much of the knowledge and information needed for enabling high-quality clinical research is stored in free-text format. Natural language processing (NLP) has been used to extract information from these sources at scale for several decades. This paper aims to present a comprehensive review of clinical NLP for the past 15 years in the UK to identify the community, depict its evolution, analyse methodologies and applications, and identify the main barriers. We collect a dataset of clinical NLP projects (n = 94; £ = 41.97 m) funded by UK funders or the European Union's funding programmes. Additionally, we extract details on 9 funders, 137 organisations, 139 persons and 431 research papers. Networks are created from timestamped data interlinking all entities, and network analysis is subsequently applied to generate insights. 431 publications are identified as part of a literature review, of which 107 are eligible for final analysis. Results show, not surprisingly, clinical NLP in the UK has increased substantially in the last 15 years: the total budget in the period of 2019-2022 was 80 times that of 2007-2010. However, the effort is required to deepen areas such as disease (sub-)phenotyping and broaden application domains. There is also a need to improve links between academia and industry and enable deployments in real-world settings for the realisation of clinical NLP's great potential in care delivery. The major barriers include research and development access to hospital data, lack of capable computational resources in the right places, the scarcity of labelled data and barriers to sharing of pretrained models.

Bridging late-life depression and chronic somatic diseases: a network analysis

The clinical presentation of late-life depression is highly heterogeneous and likely influenced by the co-presence of somatic diseases. Using a network approach, this study aims to explore how depressive symptoms are interconnected with each other, as well as with different measures of somatic disease burden in older adults. We examined cross-sectional data on 2860 individuals aged 60+ from the Swedish National Study on Aging and Care in Kungsholmen, Stockholm. The severity of sixteen depressive symptoms was clinically assessed with the Comprehensive Psychopathological Rating Scale. We combined data from individual clinical assessment and health-registers to construct eight system-specific disease clusters (cardiovascular, neurological, gastrointestinal, metabolic, musculoskeletal, respiratory, sensory, and unclassified), along with a measure of overall somatic burden. The interconnection among depressive symptoms, and with disease clusters was explored through networks based on Spearman partial correlations. Bridge centrality index and network loadings were employed to identify depressive symptoms directly connecting disease clusters and depression. Sadness, pessimism, anxiety, and suicidal thoughts were the most interconnected symptoms of the depression network, while somatic symptoms of depression were less interconnected. In the network integrating depressive symptoms with disease clusters, suicidal thoughts, reduced appetite, and cognitive difficulties constituted the most consistent bridge connections. The same bridge symptoms emerged when considering an overall measure of somatic disease burden. Suicidal thoughts, reduced appetite, and cognitive difficulties may play a key role in the interconnection between late-life depression and somatic diseases. If confirmed in longitudinal studies, these bridging symptoms could constitute potential targets in the prevention of late-life depression.

Diagnosis Test Meta-Analysis for Apolipoprotein E in Alzheimer's Disease

Objective

To evaluate the diagnostic value of apolipoprotein E (APOE) gene in Alzheimer's disease (AD).

Methods

Databases including PubMed, EMBASE, Google Scholar, Wanfang Med online, China National Knowledge Infrastructure (CNKI), and China Biomedical Literature Database (CBM) were searched for literatures in English or Chinese. No limitations on the date. The sensitivity, specificity, likelihood ratio, and diagnostic odds ratio were pooled for meta-analysis. The symmetric receiver operator characteristic curve (SROC) and Fagan's Nomogram were drawn, and metaregression and subgroup analysis were used to explore the source of heterogeneity.

Results

A total of 13 studies, including 2662 cases and 8843 controls, were analyzed. The combined sensitivity (SEN) was 0.62 (95% CI (0.58-0.66)), specificity (SPE) was 0.84 (95% CI (0.81-0.86)), the positive likelihood ratio was 3.8 (95% CI (3.3-4.3)), and the negative likelihood ratio was 0.45 (95% CI (0.41-0.49)). The area under the ROC curve was 0.80, and the diagnostic ratio (DOR) was 8. Neither publication bias was detected in Deeks' funnel plot, nor threshold effect was shown in the SROC. Metaregression analysis showed that the diagnostic methods, experimental design, and sample size contributed to the heterogeneity in SEN, while the diagnostic methods, experimental design, blind evaluation on test results, and sample size contributed to the heterogeneity in SPE. When the pretest probability was set as 50%, the posterior probability in Fagan's Nomogram was 79%, the positive likelihood ratio (LRP) was 5, and the negative likelihood ratio (LRN) was 0.42.

Conclusions

AD could neither be confirmed nor excluded by the APOE genotype test. The sensitivity and specificity of the APOE gene test were relatively low in the diagnosis of AD. The diagnostic value of APOE ε4 gene in AD was moderate; it might play an important role in the prevention of AD.

Interrater agreement in dementia diagnosis: A systematic review and meta-analysis

OBJECTIVES

Dementia remains a clinical diagnosis with a degree of subjective assessment and potential for interrater disagreement. We described interrater agreement of clinical dementia diagnosis for various diagnostic criteria.

METHODS

We conducted a PROSPERO-registered (CRD42020168245) systematic review and meta-analysis. We searched multiple cross-disciplinary databases from inception until April 2020 for relevant papers, extracted data and described study quality in duplicate. Study quality was assessed using the Guidelines for Reporting Reliability and Agreement Studies. We used random-effects models to obtain summary estimates of interrater agreement using kappa and, where possible, Gwet's AC1/2 coefficients.

RESULTS

We found 7577 titles and 22 eligible studies. Meta-analysis was possible for all-cause dementia using the Diagnostic and Statistical Manual of Mental Disorders third edition revised (DSM-III-R) criteria (kappa = 0.66, 95% CI = [0.53,0.78]), Alzheimer's disease using the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's disease and Related Disorders Association (NINCDS-ADRDA) criteria (kappa = 0.71, 95% CI = [0.65,0.77] for presence/absence and AC2 = 0.61, 95% CI = [0.53,0.70] when distinguishing probable/possible cases), and vascular dementia using the International Classification of Diseases version 10 (ICD-10) criteria kappa = 0.79 (95% CI = [0.70,0.87]). Data was more limited for other criteria and dementia types. AC1/2 coefficients generally indicated higher agreement. One study was rated as high quality.

CONCLUSIONS

Diagnostic criteria for clinical dementia may have good but imperfect agreement. This has important implications for clinical practice and research studies, which frequently assume these criteria are perfect tests, such as diagnostic test accuracy studies frequently conducted for biomarkers and neuropsychological tests, and for trials where incident dementia is the outcome.

From Normal Cognition to Cognitive Impairment and Dementia: Impact of Orthostatic Hypotension

Supplemental Digital Content is available in the text.

The role of orthostatic hypotension (OH) in the continuum of cognitive aging remains to be clarified. We sought to investigate the associations of OH with dementia, cognitive impairment, no dementia (CIND), and CIND progression to dementia in older adults while considering orthostatic symptoms. This population-based cohort study included 2532 baseline (2001–2004) dementia-free participants (age ≥60 years; 62.6% women) in the SNAC-K (Swedish National Study on Aging and Care in Kungsholmen) who were regularly examined over 12 years. We further divided the participants into a baseline CIND-free cohort and a CIND cohort. OH was defined as a decrease by ≥20/10 mm Hg in systolic/diastolic blood pressure upon standing and further divided into asymptomatic and symptomatic OH. Dementia was diagnosed following the international criteria. CIND was defined as scoring ≥1.5 SDs below age group-specific means in ≥1 cognitive domain. Data were analyzed with flexible parametric survival models, controlling for confounding factors. Of the 2532 participants, 615 were defined with OH at baseline, and 322 were diagnosed with dementia during the entire follow-up period. OH was associated with an adjusted hazard ratio of 1.40 for dementia (95% CI, 1.10–1.76), 1.15 (0.94–1.40) for CIND, and 1.54 (1.05–2.25) for CIND progression to dementia. The associations of dementia and CIND progression to dementia with asymptomatic OH were similar to overall OH, whereas symptomatic OH was only associated with CIND progression to dementia. Our study suggests that OH, even asymptomatic OH, is associated with increased risk of dementia and accelerated progression from CIND to dementia in older adults.

Sex differences in dementia and response to a lifestyle intervention: Evidence from Nordic population-based studies and a prevention trial

INTRODUCTION

Evidence on sex differences in the risk for dementia has been mixed. The goal was to assess sex differences in the development of dementia, and in the effects of a lifestyle intervention.

METHODS

Two strategies were adopted, one using combined data from three large Nordic population-based cohort studies (n = 2289), adopting dementia as outcome, and 2-year multidomain lifestyle intervention (n = 1260), adopting cognitive change as outcome.

RESULTS

There was higher risk for dementia after age 80 years in women. The positive effects of the lifestyle intervention on cognition did not significantly differ between men and women. Sex-specific analyses suggested that different vascular, lifestyle, and psychosocial risk factors are important for women and men in mid- and late-life.

CONCLUSION

Women had higher risk for dementia among the oldest individuals. Lifestyle interventions may be effectively implemented among older men and women.

Memantine, Donepezil, or Combination Therapy-What is the best therapy for Alzheimer's Disease? A Network Meta-Analysis

INTRODUCTION

Alzheimer's disease (AD) is a degenerative brain disease that progresses over time, heavily burdening patients, families, and aging societies worldwide. Memantine and donepezil are frequently used in its treatment, both as monotherapy and in combination. This multiple treatment comparison meta-analysis assessed the efficacy of these regimens and placebo in the management of AD.

METHODS

We searched PubMed, Embase, the Cochrane Library, and Wanfang Med Online and China National Knowledge Infrastructure for English and Chinese publications from the first records to 17 April 2020. Two investigators scanned articles for placebo-controlled trials of memantine and donepezil alone and in combination. We extracted data on the following outcomes: cognition, global assessment, daily activities, neuropsychiatric symptoms, adverse events, and the acceptability and cost of these treatment regimens.

RESULTS

Of 936 records screened, we included 54 trials in this analysis. The combination therapy was more effective in improving cognition (mean difference (MD)-5.01, 95% credible interval (95% Crl) -10.73 to 0.86 in the Alzheimer's Disease Assessment Scale-Cognitive Subscale; MD 9.61, 95% Crl 2.29 to 16.97 in the Severe Impairment Battery), global assessment (MD -2.88, 95% Crl -6.04 to 0.40), daily activities (MD 13.06, 95% Crl -34.04 to 58.92), and neuropsychiatric symptoms (MD -6.84, 95% Crl -10.62 to -2.82) compared with placebo. Memantine was more acceptable than placebo (MD 0.93, 95% Crl 0.69 to 1.22).

CONCLUSIONS

Memantine plus donepezil showed superior outcomes for cognition, global assessment, daily activities, and neuropsychiatric symptoms, but lower acceptability than monotherapy and placebo. Combination therapy may be more cost-effective, because memantine slows the progression of AD.

Low Mood and Risk of Dementia: The Role of Marital Status and Living Situation

OBJECTIVE

This study aims to explore whether low mood is related to an increased dementia risk in two cohorts of older adults of different generations, and whether marital status and living situation modify this association.

METHODS

Participants (≥70 years), free from dementia and living at home, were identified from two population-based studies: the Kungsholmen Project (KP; n = 1,197) and the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K; n = 1,402). Low mood was obtained by self-report (KP and SNAC-K) at baseline in 1987-89 (KP) and 2001-04 (SNAC-K). Incident dementia cases were ascertained over 9 years, using the same diagnostic procedures and comparable criteria for the two cohorts (DSM-III-R in KP and DSM-IV-TR in SNAC-K). Hazard ratios (HR) were derived from Cox proportional hazards models.

RESULTS

Those having low mood at baseline were at higher risk of dementia in both cohorts combined (HR: 1.2, 95% confidence interval (CI): 1.0-1.4) than those without low mood. However, an increased risk was detected only in those who did not have a partner (HR: 1.5, 95% CI: 1.2-1.9), or lived alone (HR: 1.5, 95% CI: 1.2-1.9), but not among those who had a partner or lived with someone (HR: 0.8, 95% CI: 0.5-1.2).

CONCLUSION

Marital status and living situation have the potential to buffer the detrimental effects of low mood on dementia onset. Thus, specific attention from health care should target individuals having low mood and who do not have a partner or live alone.

Association of Methionine to Homocysteine Status With Brain Magnetic Resonance Imaging Measures and Risk of Dementia

IMPORTANCE

Impairment of methylation status (ie, methionine to homocysteine ratio) may be a modifiable risk factor for structural brain changes and incident dementia.

OBJECTIVE

To investigate the association of serum markers of methylation status and sulfur amino acids with risk of incident dementia, Alzheimer disease (AD), and the rate of total brain tissue volume loss during 6 years.

DESIGN, SETTING, AND PARTICIPANTS

This population-based longitudinal study was performed from March 21, 2001, to October 10, 2010, in a sample of 2570 individuals aged 60 to 102 years from the Swedish Study on Aging and Care in Kungsholmen who were dementia free at baseline and underwent comprehensive examinations and structural brain magnetic resonance imaging (MRI) on 2 to 3 occasions during 6 years. Data analysis was performed from March 1, 2018, to October 1, 2018.

MAIN OUTCOMES AND MEASURES

Incident dementia, AD, and the rate of total brain volume loss.

RESULTS

This study included 2570 individuals (mean [SD] age, 73.1 [10.4] years; 1331 [56.5%] female). The methionine to homocysteine ratio was higher in individuals who consumed vitamin supplements (median, 1.9; interquartile range [IQR], 1.5-2.6) compared with those who did not (median, 1.8; IQR, 1.3-2.3; P < .001) and increased per each quartile increase of vitamin B12 or folate. In the multiadjusted model, an elevated baseline serum total homocysteine level was associated with an increased risk of dementia and AD during 6 years: for the highest homocysteine quartile compared with the lowest, the hazard ratios (HRs) were 1.60 (95% CI, 1.01-2.55) for dementia and 2.33 (95% CI, 1.26-4.30) for AD. In contrast, elevated concentrations of methionine were associated with a decreased risk of dementia (HR, 0.54; 95% CI, 0.36-0.81) for the highest quartile compared with the lowest. Higher values of the methionine to homocysteine ratio were significantly associated with lower risk of dementia and AD: for the fourth methionine-homocysteine quartile compared with the first quartile, the HR was 0.44 (95% CI, 0.27-0.71) for incident dementia and 0.43 (95% CI, 0.23-0.80) for AD. In the multiadjusted linear mixed models, a higher methionine to homocysteine ratio was associated with a decreased rate of total brain tissue volume loss during the study period (β [SE] per 1-SD increase, 0.038 [0.014]; P = .007).

CONCLUSIONS AND RELEVANCE

The methionine to homocysteine status was associated with dementia development and structural brain changes during the 6-year study period, suggesting that a higher methionine to homocysteine ratio may be important in reducing the rate of brain atrophy and decreasing the risk of dementia in older adults.

Atrial fibrillation, antithrombotic treatment, and cognitive aging: A population-based study

Objective

To examine the association of atrial fibrillation (AF) with cognitive decline and dementia in old age, and to explore the cognitive benefit of antithrombotic treatment in patients with AF.

Methods

This population-based cohort study included 2,685 dementia-free participants from the Swedish National Study on Aging and Care in Kungsholmen, who were regularly examined from 2001–2004 to 2010–2013. AF was ascertained from clinical examination, ECG, and patient registry. Global cognitive function was assessed using the Mini-Mental State Examination. We followed the DSM-IV criteria for the diagnosis of dementia, the NINDS-AIREN (National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherché et l'Enseignement en Neurosciences) criteria for vascular dementia, and the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association) criteria for Alzheimer disease. Data were analyzed using multiple linear mixed-effects and Cox regression models.

Results

We identified 243 participants (9.1%) with AF at baseline. During the 9-year follow-up period, 279 participants (11.4%) developed AF and 399 (14.9%) developed dementia. As a time-varying variable, AF was significantly associated with a faster annual Mini-Mental State Examination decline (β coefficient = −0.24, 95% confidence interval [CI]: −0.31 to −0.16) and an increased hazard ratio (HR) of all-cause dementia (HR = 1.40, 95% CI: 1.11–1.77) and vascular and mixed dementia (HR = 1.88, 95% CI: 1.09–3.23), but not Alzheimer disease (HR = 1.33, 95% CI: 0.92–1.94). Among people with either prevalent or incident AF, use of anticoagulant drugs, but not antiplatelet treatment, was associated with a 60% decreased risk of dementia (HR = 0.40, 95% CI: 0.18–0.92).

Conclusion

AF is associated with a faster global cognitive decline and an increased risk of dementia in older people. Use of anticoagulant drugs may reduce dementia risk in patients with AF.

MRI load of cerebral microvascular lesions and neurodegeneration, cognitive decline, and dementia

Objective

To explore the differential associations of neurodegeneration and microvascular lesion load with cognitive decline and dementia in older people and the modifying effect of the APOE genotype on these associations.

Methods

A sample of 436 participants (age ≥ 60 years) was derived from the population-based Swedish National study on Aging and Care in Kungsholmen, Stockholm, and clinically examined at baseline (2001–2003) and 3 occasions during the 9-year follow-up. At baseline, we assessed microvascular lesion load using a summary score for MRI markers of lacunes, white matter hyperintensities (WMHs), and perivascular spaces and neurodegeneration load for markers of enlarged ventricles, smaller hippocampus, and smaller gray matter. We assessed cognitive function using the Mini-Mental State Examination (MMSE) test and diagnosed dementia following the Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. We analyzed data using linear mixed-effects, mediation, and random-effects Cox models.

Results

During the follow-up, 46 participants were diagnosed with dementia. Per 1-point increase in microvascular lesion and neurodegeneration score (range 0–3) was associated with multiple adjusted β-coefficients of −0.35 (95% confidence interval, −0.51 to −0.20) and −0.44 (−0.56 to −0.32), respectively, for the MMSE score and multiple adjusted hazard ratios of 1.68 (1.12–2.51) and 2.35 (1.58–3.52), respectively, for dementia; carrying APOE ε4 reinforced the associations with MMSE decline. WMH volume changes during the follow-up mediated 66.9% and 12.7% of the total association of MMSE decline with the baseline microvascular score and neurodegeneration score, respectively.

Conclusions

Both cerebral microvascular lesion and neurodegeneration loads are strongly associated with cognitive decline and dementia. The cognitive decline due to microvascular lesions is exacerbated by APOE ε4 and is largely attributed to progression and development of microvascular lesions.

Sleep disturbances and dementia risk: A multicenter study

INTRODUCTION

Few longitudinal studies assessed whether sleep disturbances are associated with dementia risk.

METHODS

Sleep disturbances were assessed in three population-based studies (H70 study and Kungsholmen Project [Sweden]; Cardiovascular Risk Factors, Aging and Dementia study [Finland]). Late-life baseline analyses (3-10 years follow-up) used all three studies (N = 1446). Baseline ages ≈ 70 years (Cardiovascular Risk Factors, Aging and Dementia, H70), and ≈84 years (Kungsholmen Project). Midlife baseline (age ≈ 50 years) analyses used Cardiovascular Risk Factors, Aging and Dementia (21 and 32 years follow-up) (N = 1407).

RESULTS

Midlife insomnia (fully adjusted hazard ratio = 1.24, 95% confidence interval = 1.02-1.50) and late-life terminal insomnia (fully adjusted odds ratio = 1.94, 95% confidence interval = 1.08-3.49) were associated with a higher dementia risk. Late-life long sleep duration (>9 hours) was also associated with an increased dementia risk (adjusted odds ratio = 3.98, 95% confidence interval = 1.87-8.48).

DISCUSSION

Midlife insomnia and late-life terminal insomnia or long sleep duration were associated with a higher late-life dementia risk.

16-Year Survival of the Canadian Collaborative Cohort of Related Dementias

Background Survival estimates are integral to care for patients diagnosed with dementia. Few Canadian studies have carried out long-term follow-up of well-described cohorts, analyzing survival related to multiple risk factors. Methods Survival analysis of an inception cohort enrolled at a British Columbia (BC) tertiary dementia referral clinic between 1997 and 1999 was undertaken. Vital status was completed for 168 patients diagnosed with dementia. An evaluation of the effects of demographics, vascular risk factors, cognitive and functional ratings, apolipoprotein 4-status, and cholinesterase use on survival was performed using a log-rank test and time-dependent Cox regression. Survival of this dementia cohort was compared with the age-matched life expectancy of persons in BC. Results In all, 158/168 (94.0%) subjects died over 16.6 years, with a median survival of 7.08 years. Risk factors associated with shorter survival in dementia groups included age of onset ≥80 (hazard ratio [HR] 1.56, 95% confidence interval [CI] 1.05-2.32); greater functional disability (Disability Assessment for Dementia<55% [HR 1.47, 95% CI 1.04-2.08]); and cumulative medical illness severity (Cumulative Illness Rating Scale≥7 [HR 1.51, 95% CI 1.08-2.12)]. Compared with the BC population, years of potential life lost for dementia subjects aged <65 was 15.36 years, and for dementia subjects aged ≥80 it was 1.82 years. Conclusions Survival in dementia subjects is shorter than population life expectancies for each age strata, with greatest impact on younger patients. For people diagnosed with dementia, age ≥80 years, cumulative medical illness severity, and functional disabilities are the most significant survival predictors and can be used to guide prognosis.

Tooth loss is associated with accelerated cognitive decline and volumetric brain differences: a population-based study

Tooth loss has been related to cognitive impairment; however, its relation to structural brain differences in humans is unknown. Dementia-free participants (n = 2715) of age ≥60 years were followed up for up to 9 years. A subsample (n = 394) underwent magnetic resonance imaging at baseline. Information on tooth loss was collected at baseline, and cognitive function was assessed using the Mini-Mental State Examination at baseline and at follow-ups. Data were analyzed using linear mixed effects models and linear regression models. At baseline, 404 (14.9%) participants had partial tooth loss, and 206 (7.6%) had complete tooth loss. Tooth loss was significantly associated with a steeper cognitive decline (β: -0.18, 95% confidence interval [CI]: -0.24 to -0.11) and remained significant after adjusting for or stratifying by potential confounders. In cross-sectional analyses, persons with complete or partial tooth loss had significantly lower total brain volume (β: -28.89, 95% CI: -49.33 to -8.45) and gray matter volume (β: -22.60, 95% CI: -38.26 to -6.94). Thus, tooth loss may be a risk factor for accelerated cognitive aging.

Sleep disturbances and later cognitive status: a multi-centre study

OBJECTIVE

To investigate the associations between sleep disturbances in mid-life and late-life and late-life cognitive status.

METHODS

In four population-based studies (three Swedish studies: H70 study, Kungsholmen Project (KP) and The Swedish Panel Study of Living Conditions of the Oldest Old (SWEOLD); and one Finnish study: Cardiovascular Risk Factors, Aging and Dementia (CAIDE)), participants provided self-reports on insomnia, nightmares and general sleep problems. Late-life cognitive status was measured by the Mini Mental State Exam (MMSE). The associations between late-life sleep disturbances and cognition 3-11 years later were investigated across all studies (n = 3210). Mean baseline ages were 70 (CAIDE, H70 and SWEOLD), and 84 years (KP). Additional analyses examined the association between midlife sleep and late-life cognition using CAIDE (21 and 31 years follow-up, n = 1306, mean age 50 years), and SWEOLD (20-24 years follow-up, n = 2068, mean age 58 years). Ordered logistic regressions, adjusted for potential baseline confounders, were used in the analyses.

RESULTS

Late-life sleep disturbances were associated with poorer cognition after 3-11 years (fully adjusted β = -0.12, 95% CI = -0.24 to -0.01). Midlife nightmares and insomnia were also associated with lower MMSE scores (fully adjusted β = -0.28, 95% CI = -0.49 to -0.07 and β = -0.20, 95% CI = -0.39 to -0.01), although the latter association was attenuated after adjusting for lifestyle/health-related confounders. Midlife general sleep problems were not associated with late-life MMSE performance.

CONCLUSIONS

Sleep disturbances and midlife nightmares were associated with lower MMSE scores, which suggests that sleep disturbances in earlier life stages can be associated with worse late-life cognition.

Antihypertensive Medication Regimen Intensity and Incident Dementia in an Older Population

OBJECTIVE

To investigate the association between antihypertensive medication regimen intensity and risk of incident dementia in an older population.

DESIGN

Prospective, longitudinal cohort study.

PARTICIPANTS/SETTING

A total of 1208 participants aged ≥78 years, free of dementia, and residing in central Stockholm at baseline (2001-2004).

MEASUREMENTS

Participants were examined at 3- and 6-year follow-up to detect incident dementia. Data were collected through face-to-face interviews, clinical examinations, and laboratory tests. Data on antihypertensive use were obtained by a physician through patient self-report, visual inspection, or medical records. Cox proportional hazards models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between time-varying antihypertensive regimen intensity and incident dementia after adjusting for potential confounders.

RESULTS

During the follow-up period, 125 participants were diagnosed with dementia. Participants who developed dementia were more likely to have vascular disease at baseline (66.4% vs 55.3%, P = .02). In fully adjusted analyses, the number of antihypertensive classes (HR 0.68, 95% CI 0.55-0.84) and total prescribed daily dose (HR 0.70, 95% CI 0.57-0.86) were significantly associated with reduced dementia risk. After considering all-cause mortality as a competing risk, the number (HR 0.75, 95% CI 0.62-0.91) and doses (HR 0.71, 95% CI 0.59-0.86) of antihypertensive classes, and the independent use of diuretics (HR 0.66, 95% CI 0.44-0.99), were significantly associated with lower dementia risk.

CONCLUSIONS

Greater intensity of antihypertensive drug use among older people may be associated with reduced incidence of dementia.

Association of lifelong exposure to cognitive reserve-enhancing factors with dementia risk: A community-based cohort study

BACKGROUND

Variation in the clinical manifestation of dementia has been associated with differences in cognitive reserve, although less is known about the cumulative effects of exposure to cognitive reserve factors over the life course. We examined the association of cognitive reserve-related factors over the lifespan with the risk of dementia in a community-based cohort of older adults.

METHODS AND FINDINGS

Information on early-life education, socioeconomic status, work complexity at age 20, midlife occupation attainment, and late-life leisure activities was collected in a cohort of dementia-free community dwellers aged 75+ y residing in the Kungsholmen district of Stockholm, Sweden, in 1987-1989. The cohort was followed up to 9 y (until 1996) to detect incident dementia cases. To exclude preclinical phases of disease, participants who developed dementia at the first follow-up examination 3 y after the baseline were excluded (n = 602 after exclusions). Structural equation modelling was used to generate latent factors of cognitive reserve from three periods over the life course: early (before 20 y), adulthood (around 30-55 y), and late life (75 y and older). The correlation between early- and adult-life latent factors was strong (γ = 0.9), whereas early-late (γ = 0.27) and adult-late (γ = 0.16) latent factor correlations were weak. One hundred forty-eight participants developed dementia during follow-up, and 454 remained dementia-free. The relative risk (RR) of dementia was estimated using Cox models with life-course cognitive reserve-enhancing factors modelled separately and simultaneously to assess direct and indirect effects. The analysis was repeated among carriers and noncarriers of the apolipoprotein E (APOE) ε4 allele. A reduced risk of dementia was associated with early- (RR 0.57; 95% CI 0.36-0.90), adult- (RR 0.60; 95% CI 0.42-0.87), and late-life (RR 0.52; 95% CI 0.37-0.73) reserve-enhancing latent factors in separate multivariable Cox models. In a mutually adjusted model, which may have been imprecisely estimated because of strong correlation between early- and adult-life factors, the late-life factor preserved its association (RR 0.65; 95% CI 0.45-0.94), whereas the effect of midlife (RR 0.73; 95% CI 0.50-1.06) and early-life factors (RR 0.76; 95% CI 0.47-1.23) on the risk of dementia was attenuated. The risk declined progressively with cumulative exposure to reserve-enhancing latent factors, and having high scores on cognitive reserve-enhancing composite factors in all three periods over the life course was associated with the lowest risk of dementia (RR 0.40; 95% CI 0.20-0.81). Similar associations were detected among APOE ε4 allele carriers and noncarriers. Limitations include measurement error and nonresponse, with both biases likely favouring the null. Strong correlation between early- and adult-life latent factors may have led to a loss in precision when estimating mutually adjusted effects of all periods.

CONCLUSIONS

In this study, cumulative exposure to reserve-enhancing factors over the lifespan was associated with reduced risk of dementia in late life, even among individuals with genetic predisposition.

Inter-Rater Agreement in the Clinical Diagnosis of Cognitive Status: Data from the Neurological Disorders in Central Spain 2 Pilot Study

Background: To assess the diagnostic agreement of cognitive status (dementia, mild cognitive impairment (MCI), normal cognition) among neurologists in the field of neurological disorders in Central Spain 2 study. Methods: Full medical histories of 30 individuals were provided to 27 neurologists: 9 seniors, 10 juniors and 8 residents. For each case, we were asked to assign a diagnosis of dementia, MCI or normal cognition using the National Institute on Aging-Alzheimer's Association workgroup (NIA-AA) core clinical criteria for all-cause dementia, Winblad et al. criteria for MCI, and analyze intensity and etiology if dementia was diagnosed. Inter-rater agreement was assessed both with percent concordance and non-weighted κ statistics. Results: Overall inter-rater agreement on cognitive status was κ = 0.76 (95% CI 0.65-0.86), being slightly higher among junior neurologists (κ = 0.85, 95% CI 0.73-0.95) than among seniors (κ = 0.71, 95% CI 0.59-0.83) and residents (κ = 0.69, 95% CI 0.54-0.81) but without statistical significance among groups. Dementia severity showed an overall κ of 0.34, 0.44 and 0.64 for mild, moderate and severe dementia respectively. Conclusions: Substantial agreement was demonstrated for the diagnosis of cognitive status (dementia, MCI and normal cognition) among neurologists of different levels of experience in a population-based epidemiological study using NIA-AA and Winblad et al. criteria. The agreement rate was lower in the diagnosis of dementia severity.

Mini-Mental State Examination (MMSE) for the detection of dementia in clinically unevaluated people aged 65 and over in community and primary care populations

BACKGROUND

The Mini Mental State Examination (MMSE) is a cognitive test that is commonly used as part of the evaluation for possible dementia.

OBJECTIVES

To determine the diagnostic accuracy of the Mini-Mental State Examination (MMSE) at various cut points for dementia in people aged 65 years and over in community and primary care settings who had not undergone prior testing for dementia.

SEARCH METHODS

We searched the specialised register of the Cochrane Dementia and Cognitive Improvement Group, MEDLINE (OvidSP), EMBASE (OvidSP), PsycINFO (OvidSP), LILACS (BIREME), ALOIS, BIOSIS previews (Thomson Reuters Web of Science), and Web of Science Core Collection, including the Science Citation Index and the Conference Proceedings Citation Index (Thomson Reuters Web of Science). We also searched specialised sources of diagnostic test accuracy studies and reviews: MEDION (Universities of Maastricht and Leuven, www.mediondatabase.nl), DARE (Database of Abstracts of Reviews of Effects, via the Cochrane Library), HTA Database (Health Technology Assessment Database, via the Cochrane Library), and ARIF (University of Birmingham, UK, www.arif.bham.ac.uk). We attempted to locate possibly relevant but unpublished data by contacting researchers in this field. We first performed the searches in November 2012 and then fully updated them in May 2014. We did not apply any language or date restrictions to the electronic searches, and we did not use any methodological filters as a method to restrict the search overall.

SELECTION CRITERIA

We included studies that compared the 11-item (maximum score 30) MMSE test (at any cut point) in people who had not undergone prior testing versus a commonly accepted clinical reference standard for all-cause dementia and subtypes (Alzheimer disease dementia, Lewy body dementia, vascular dementia, frontotemporal dementia). Clinical diagnosis included all-cause (unspecified) dementia, as defined by any version of the Diagnostic and Statistical Manual of Mental Disorders (DSM); International Classification of Diseases (ICD) and the Clinical Dementia Rating.

DATA COLLECTION AND ANALYSIS

At least three authors screened all citations.Two authors handled data extraction and quality assessment. We performed meta-analysis using the hierarchical summary receiver-operator curves (HSROC) method and the bivariate method.

MAIN RESULTS

We retrieved 24,310 citations after removal of duplicates. We reviewed the full text of 317 full-text articles and finally included 70 records, referring to 48 studies, in our synthesis. We were able to perform meta-analysis on 28 studies in the community setting (44 articles) and on 6 studies in primary care (8 articles), but we could not extract usable 2 x 2 data for the remaining 14 community studies, which we did not include in the meta-analysis. All of the studies in the community were in asymptomatic people, whereas two of the six studies in primary care were conducted in people who had symptoms of possible dementia. We judged two studies to be at high risk of bias in the patient selection domain, three studies to be at high risk of bias in the index test domain and nine studies to be at high risk of bias regarding flow and timing. We assessed most studies as being applicable to the review question though we had concerns about selection of participants in six studies and target condition in one study.The accuracy of the MMSE for diagnosing dementia was reported at 18 cut points in the community (MMSE score 10, 14-30 inclusive) and 10 cut points in primary care (MMSE score 17-26 inclusive). The total number of participants in studies included in the meta-analyses ranged from 37 to 2727, median 314 (interquartile range (IQR) 160 to 647). In the community, the pooled accuracy at a cut point of 24 (15 studies) was sensitivity 0.85 (95% confidence interval (CI) 0.74 to 0.92), specificity 0.90 (95% CI 0.82 to 0.95); at a cut point of 25 (10 studies), sensitivity 0.87 (95% CI 0.78 to 0.93), specificity 0.82 (95% CI 0.65 to 0.92); and in seven studies that adjusted accuracy estimates for level of education, sensitivity 0.97 (95% CI 0.83 to 1.00), specificity 0.70 (95% CI 0.50 to 0.85). There was insufficient data to evaluate the accuracy of the MMSE for diagnosing dementia subtypes.We could not estimate summary diagnostic accuracy in primary care due to insufficient data.

AUTHORS' CONCLUSIONS

The MMSE contributes to a diagnosis of dementia in low prevalence settings, but should not be used in isolation to confirm or exclude disease. We recommend that future work evaluates the diagnostic accuracy of tests in the context of the diagnostic pathway experienced by the patient and that investigators report how undergoing the MMSE changes patient-relevant outcomes.

HHEX_23 AA Genotype Exacerbates Effect of Diabetes on Dementia and Alzheimer Disease: A Population-Based Longitudinal Study

BACKGROUND

Research has suggested that variations within the IDE/HHEX gene region may underlie the association of type 2 diabetes with Alzheimer disease (AD). We sought to explore whether IDE genes play a role in the association of diabetes with dementia, AD, and structural brain changes using data from two community-based cohorts of older adults and a subsample with structural MRI.

METHODS AND FINDINGS

The first cohort, which included dementia-free adults aged ≥75 y (n = 970) at baseline, was followed for 9 y to detect incident dementia (n = 358) and AD (n = 271) cases. The second cohort (for replication), which included 2,060 dementia-free participants aged ≥60 y at baseline, was followed for 6 y to identify incident dementia (n = 166) and AD (n = 121) cases. A subsample (n = 338) of dementia-free participants from the second cohort underwent MRI. HHEX_23 and IDE_9 were genotyped, and diabetes (here including type 2 diabetes and prediabetes) was assessed. In the first cohort, diabetes led to an adjusted hazard ratio (HR) of 1.73 (95% CI 1.19-2.32) and 1.66 (95% CI 1.06-2.40) for dementia and AD, respectively, among all participants. Compared to people carrying the GG genotype without diabetes, AA genotype carriers with diabetes had an adjusted HR of 5.54 (95% CI 2.40-7.18) and 4.81 (95% CI 1.88-8.50) for dementia and AD, respectively. There was a significant interaction between HHEX_23-AA and diabetes on dementia (HR 4.79, 95% CI 1.63-8.90, p = 0.013) and AD (HR 3.55, 95% CI 1.45-9.91, p = 0.025) compared to the GG genotype without diabetes. In the second cohort, the HRs were 1.68 (95% CI 1.04-2.99) and 1.64 (1.02-2.33) for the diabetes-AD and dementia-AD associations, respectively, and 4.06 (95% CI 1.06-7.58, p = 0.039) and 3.29 (95% CI 1.02-8.33, p = 0.044) for the interactions, respectively. MRI data showed that HHEX_23-AA carriers with diabetes had significant structural brain changes compared to HHEX_23-GG carriers without diabetes. No joint effects of IDE_9 and diabetes on dementia were shown. As a limitation, the sample sizes were small for certain subgroups.

CONCLUSIONS

A variant in the HHEX_23 gene interacts with diabetes to be associated with a substantially increased risk of dementia and AD, and with structural brain changes among dementia-free elderly people.

A change in sleep pattern may predict Alzheimer disease

OBJECTIVE

Sleep problems may adversely affect neuronal health. We examined a subjective report of change (reduced duration and/or depth) in sleep pattern in relation to subsequent risk of incident all-cause dementia and Alzheimer disease (AD) over 9 years.

METHODS

This longitudinal study used data from a population-based sample of 214 Swedish adults aged 75 and over who were dementia-free both at baseline and at first follow-up (3 years later). The sample was 80% female and, on average, 83.4 years of age at baseline. All participants underwent a thorough clinical examination to ascertain all-cause dementia and AD.

RESULTS

Forty percent of participants reported a change in sleep duration at baseline. Between the 6th and 9th year after baseline, 28.5% were diagnosed with all-cause dementia, 22.0% of whom had AD. Reduced sleep was associated with a 75% increased all-cause dementia risk (hazard ratio: 1.75; 95% confidence interval: 1.04-2.93; Wald = 4.55, df = 1, p = 0.035) and double the risk of AD (hazard ratio: 2.01; 95% confidence interval: 1.12-3.61; Wald = 5.47, df = 1, p = 0.019) after adjusting for age, gender, and education. The results remained after adjusting for lifestyle and vascular factors but not after adjusting for depressive symptoms. No evidence supported a moderating effect of the use of sleeping pills, and the sleep-dementia relationship remained after controlling for the presence of the apolipoprotein E ε4 allele.

CONCLUSION

Self-reported sleep problems may increase the risk for dementia, and depressive symptoms may explain this relationship. Future research should determine whether treatment, in particular, behavioral or nonpharmacologic treatment, may represent one avenue toward reduction of dementia risk in late life.

Incidence and predictors of multimorbidity in the elderly: a population-based longitudinal study

BACKGROUND

We aimed to calculate 3-year incidence of multimorbidity, defined as the development of two or more chronic diseases in a population of older people free from multimorbidity at baseline. Secondly, we aimed to identify predictors of incident multimorbidity amongst life-style related indicators, medical conditions and biomarkers.

METHODS

Data were gathered from 418 participants in the first follow up of the Kungsholmen Project (Stockholm, Sweden, 1991-1993, 78+ years old) who were not affected by multimorbidity (149 had none disease and 269 one disease), including a social interview, a neuropsychological battery and a medical examination.

RESULTS

After 3 years, 33.6% of participants who were without disease and 66.4% of those with one disease at baseline, developed multimorbidity: the incidence rate was 12.6 per 100 person-years (95% CI: 9.2-16.7) and 32.9 per 100 person-years (95% CI: 28.1-38.3), respectively. After adjustments, worse cognitive function (OR, 95% CI, for 1 point lower Mini-Mental State Examination: 1.22, 1.00-1.48) was associated with increased risk of multimorbidity among subjects with no disease at baseline. Higher age was the only predictor of multimorbidity in persons with one disease at baseline.

CONCLUSIONS

Multimorbidity has a high incidence at old age. Mental health-related symptoms are likely predictors of multimorbidity, suggesting a strong impact of mental disorders on the health of older people.

The influence of multimorbidity on clinical progression of dementia in a population-based cohort

Introduction

Co-occurrence with other chronic diseases may influence the progression of dementia, especially in case of multiple chronic diseases. We aimed to verify whether multimorbidity influenced cognitive and daily functioning during nine years after dementia diagnosis compared with the influence in persons without dementia.

Methods

In the Kungsholmen Project, a population-based cohort study, we followed 310 persons with incident dementia longitudinally. We compared their trajectories with those of 679 persons without dementia. Progression was studied for cognition and activities of daily life (ADLs), measured by MMSE and Katz Index respectively. The effect of multimorbidity and its interaction with dementia status was studied using individual growth models.

Results

The mean (SD) follow-up time was 4.7 (2.3) years. As expected, dementia related to both the decline in cognitive and daily functioning. Irrespective of dementia status, persons with more diseases had significantly worse baseline daily functioning. In dementia patients having more diseases also related to a significantly faster decline in daily functioning. Due to the combination of lower functioning in ADLs at baseline and faster decline, dementia patients with multimorbidity were about one to two years ahead of the decline of dementia patients without any co-morbidity. In persons without dementia, no significant decline in ADLs over time was present, nor was multimorbidity related to the decline rate. Cognitive decline measured with MMSE remained unrelated to the number of diseases present at baseline.

Conclusion

Multimorbidity was related to baseline daily function in both persons with and without dementia, and with accelerated decline in people with dementia but not in non-demented individuals. No relationship of multimorbidity with cognitive functioning was established. These findings imply a strong interconnection between physical and mental health, where the greatest disablement occurs when both somatic and mental disorders are present.

Inhibition of ERK-DLP1 signaling and mitochondrial division alleviates mitochondrial dysfunction in Alzheimer's disease cybrid cell

Mitochondrial dysfunction is an early pathological feature of Alzheimer's disease (AD). The underlying mechanisms and strategies to repair it remain unclear. Here, we demonstrate for the first time the direct consequences and potential mechanisms of mitochondrial functional defects associated with abnormal mitochondrial dynamics in AD. Using cytoplasmic hybrid (cybrid) neurons with incorporated platelet mitochondria from AD and age-matched non-AD human subjects into mitochondrial DNA (mtDNA)-depleted neuronal cells, we observed that AD cybrid cells had significant changes in morphology and function; such changes associate with altered expression and distribution of dynamin-like protein (DLP1) and mitofusin 2 (Mfn2). Treatment with antioxidant protects against AD mitochondria-induced extracellular signal-regulated kinase (ERK) activation and mitochondrial fission-fusion imbalances. Notably, inhibition of ERK activation not only attenuates aberrant mitochondrial morphology and function but also restores the mitochondrial fission and fusion balance. These effects suggest a role of oxidative stress-mediated ERK signal transduction in modulation of mitochondrial fission and fusion events. Further, blockade of the mitochondrial fission protein DLP1 by a genetic manipulation with a dominant negative DLP1 (DLP1(K38A)), its expression with siRNA-DLP1, or inhibition of mitochondrial division with mdivi-1 attenuates mitochondrial functional defects observed in AD cybrid cells. Our results provide new insights into mitochondrial dysfunction resulting from changes in the ERK-fission/fusion (DLP1) machinery and signaling pathway. The protective effect of mdivi-1 and inhibition of ERK signaling on maintenance of normal mitochondrial structure and function holds promise as a potential novel therapeutic strategy for AD.

The Effect of Lipoic Acid Therapy on Cognitive Functioning in Patients with Alzheimer's Disease

Diabetes mellitus (DM) is an important risk factor for Alzheimer's disease (AD). Most diabetic patients have insulin resistance (IR) that is associated with compensatory hyperinsulinemia, one of the mechanisms suggested for increased AD risk in patients with DM. Alpha-lipoic acid (ALA) is a disulfide molecule with antioxidant properties that has positive effects on glucose metabolism and IR. This study evaluated the effect of ALA treatment (600 mg/day) on cognitive performances in AD patients with and without DM. One hundred and twenty-six patients with AD were divided into two groups, according to DM presence (group A) or absence (group B). Cognitive functions were assessed by MMSE, Alzheimer's Disease Assessment Scale-cognitive (ADAS-Cog), Clinician's Interview-Based Impression of Severity (CIBIC), Clinical Dementia Rating (CDR), and Alzheimer's Disease Functional and Change Scale (ADFACS). IR was assessed by HOMA index. At the end of the study, MMSE scores showed a significant improvement in 43% patients of group A (26 subjects) and 23% of group B (15 subjects), compared to baseline (P = .001). Also ADAS-Cog, CIBIC, and ADFACS scores showed a significant improvement in group A versus group B. IR was higher in group A. Our study suggests that ALA therapy could be effective in slowing cognitive decline in patients with AD and IR.

How can elderly apolipoprotein E ε4 carriers remain free from dementia?

Apolipoprotein E (APOE) ε4 is a major risk factor for Alzheimer's disease (AD) and dementia, but not all ε4 carriers develop dementia. We sought to identify factors that may play a role in modifying the risk of dementia due to ε4. A cognitively intact cohort (n = 932, age ≥ 75) was followed for 9 years to detect incident dementia cases. At baseline, information on education, leisure activities, and vascular risk factors was collected, and APOE was genotyped. During the follow-up, 324 subjects developed dementia, including 247 AD cases. The hazard ratio (HR, 95% confidence interval [95% CI]) of dementia related to the ε4 was 1.39 (1.11-1.76), while the risk was reduced when ε4 carriers had high education, no vascular risk factors, or high score of leisure activities. Among ε4 carriers, the multiadjusted HRs of dementia that were associated with high education, high level of leisure activities, and absence of vascular risk factors were 0.59 (0.40-0.87), 0.49 (0.29-0.85), and 0.61 (0.41-0.90), respectively. The ε4 carriers with these factors had about 1.2 years delayed time to dementia onset compared with those without these factors. High education, active leisure activities, or maintaining vascular health seems to reduce the risk of dementia related to APOE ε4. The ε4 carriers with these characteristics appear to have similar dementia-free survival time to non-ε4 carriers.

Accelerated progression from mild cognitive impairment to dementia in people with diabetes

OBJECTIVE

The effect of diabetes on mild cognitive impairment (MCI) and its conversion to dementia remains controversial. We sought to examine whether diabetes and pre-diabetes are associated with MCI and accelerate the progression from MCI to dementia.

RESEARCH DESIGN AND METHODS

In the Kungsholmen Project, 963 cognitively intact participants and 302 subjects with MCI (120 with amnestic MCI [aMCI] and 182 with other cognitive impairment no dementia [oCIND]) age ≥ 75 years were identified at baseline. The two cohorts were followed for 9 years to detect the incident MCI and dementia following international criteria. Diabetes was ascertained based on a medical examination, hypoglycemic medication use, and random blood glucose level ≥ 11.0 mmol/l. Pre-diabetes was defined as random blood glucose level of 7.8-11.0 mmol/l in diabetes-free participants. Data were analyzed using standard and time-dependent Cox proportional-hazards models.

RESULTS

During the follow-up period, in the cognitively intact cohort, 182 people developed MCI (42 aMCI and 140 oCIND), and 212 developed dementia. In the MCI cohort, 155 subjects progressed to dementia, the multi-adjusted hazard ratio (95% CI) of dementia was 2.87 (1.30-6.34) for diabetes, and 4.96 (2.27-10.84) for pre-diabetes. In a Kaplan-Meier survival analysis, diabetes and pre-diabetes accelerated the progression from MCI to dementia by 3.18 years. Diabetes and pre-diabetes were neither cross-sectionally nor longitudinally associated with MCI.

CONCLUSIONS

Diabetes and pre-diabetes substantially accelerate the progression from MCI to dementia, and anticipate dementia occurrence by more than 3 years in people with MCI. The association of diabetes with the development of MCI is less evident in old people.

Effects of insulinic therapy on cognitive impairment in patients with Alzheimer disease and diabetes mellitus type-2

BACKGROUND

Type-2 Diabetes Mellitus (DM-2) is an important risk factor for Alzheimer disease (AD) and vascular dementia (VD). The role of insulinic therapy on cognitive decline is controversial.

OBJECTIVE

To evaluate cognitive impairment in patients with AD and DM-2 treated with either oral antidiabetic drugs or combination of insulin with other diabetes medications.

METHODS

104 patients with mild-to-moderate AD and DM-2 were divided into two groups, according to antidiabetic pharmacotherapy: group A, patients treated with oral antidiabetic drugs and group B, patients treated with insulin combined with other oral antidiabetic medications. Cognitive functions were assessed by the Mini Mental State Examination (MMSE) and the Clinician's Global Impression (CGI), with a follow-up of 12 months.

RESULTS

At the end of the study, the MMSE scores showed a significant worsening in 56.5% patients of group A and in 23.2% patients of group B, compared to baseline MMSE scores (P=.001). Also CGI-C scores showed a significant worsening for all domains after 12 months in group A vs group B (P=.001). The two groups were matched for body mass index, serum lipids, triglycerides, Apo epsilon4 allele and smoke habit. Conversely, ischemic heart disease and hypertension were significantly higher in group B (P=.002). After adjustment for this risk variables, our results remained significant (P=.001).

CONCLUSIONS

Our study suggests that insulinic therapy could be effective in slowing cognitive decline in patients with AD.

Uncontrolled diabetes increases the risk of Alzheimer's disease: a population-based cohort study

AIMS/HYPOTHESIS

Diabetes has been related to Alzheimer's disease with inconsistent findings. We aimed to clarify the association of diabetes with different dementing disorders taking into account glycaemic control, and to explore the link between glucose dysregulation and neurodegeneration.

METHODS

A dementia-free cohort (n = 1,248) aged >or=75 years was longitudinally examined to detect dementia, Alzheimer's disease and vascular dementia (VaD) cases (Diagnostic and Statistical Manual of Mental Disorders, revised third edition [DSM-III-R] criteria). The Alzheimer's disease diagnoses were subdivided into Alzheimer's disease with stroke and Alzheimer's disease without hypertension, heart disease and stroke. Diabetes was ascertained based on medical history, or hypoglycaemic medication use, or a random blood glucose level >or=11.0 mmol/l, which included undiagnosed diabetes when neither a history of diabetes nor hypoglycaemic drugs use was present. Uncontrolled diabetes was classified as a random blood glucose level >or=11.0 mmol/l in diabetic patients. Borderline diabetes was defined as a random blood glucose level of 7.8-11.0 mmol/l in diabetes-free individuals. Cox models were used to estimate HRs.

RESULTS

During the 9 year follow-up, 420 individuals developed dementia, including 47 with VaD and 320 with Alzheimer's disease (of the 320 Alzheimer's disease cases, 78 had previous, temporally unrelated stroke, and 137 had no major vascular comorbidities). Overall diabetes was only related to VaD (HR 3.21, 95% CI 1.20-8.63). Undiagnosed diabetes led to an HR of 3.29 (95% CI 1.20-9.01) for Alzheimer's disease. Diabetic patients with random blood glucose levels <7.8 mmol/l showed no increased dementia risk. Uncontrolled and borderline diabetes were further associated with Alzheimer's disease without vascular comorbidities.

CONCLUSIONS/INTERPRETATION

Uncontrolled diabetes increases the risk of Alzheimer's disease and VaD. Our findings suggest a direct link between glucose dysregulation and neurodegeneration.

Pattern of participation in leisure activities among older people in relation to their health conditions and contextual factors: a survey in a Swedish urban area

The objective of this study is to describe the pattern of participation in leisure activities in an older population in relation to contextual factors as well as to mental and physical health. A cohort of 1,623 participants aged 75 or older living in Stockholm, Sweden was asked to list all the leisure activities they were engaged in. These were successively organised into 31 major categories and further grouped into mental, social, physical, productive and recreational types. The pattern of participation was examined in relation to age, gender, contextual factors (education, social network) and health status (depressive symptoms, cognitive impairment, dementia, somatic diseases and physical limitation). In spite of their advanced age, the majority of the population was active, as 70 per cent had participated in at least one activity. Reading (19%) was the most prevalent individual activity, and mental activities (43%) the most prevalent activity type. Older age, female gender, low education status, having a poor or limited social network, mental disorders, and physical limitation, were all factors correlated with a decreased engagement in ‘at least one activity’. Contextual factors and health-related factors were related to the five activity types in different ways. The pattern of participation in leisure activities is associated with multiple factors and their recognition is essential to the facilitation of an active lifestyle in the older population.

Mild cognitive impairment in the general population: occurrence and progression to Alzheimer disease

OBJECTIVES

Our aims were to 1) detect the occurrence of three mild cognitive impairment (MCI) subtypes in the general population; 2) identify cases of cognitive impairment which are not detected by current operational criteria for MCI and; 3) determine the predictive value of the subtypes for identifying future Alzheimer disease (AD).

DESIGN

Three-year prospective study.

SETTING

Population-based Swedish study, the Kungsholmen Project.

PARTICIPANTS

Three hundred seventy-nine nondemented older adults aged 75-95.

MEASUREMENTS

Standard plus modified MCI criteria were applied at baseline. In the modified definitions, the requirement for normal general cognition was removed. A category for persons without MCI who had only global cognitive deficits was added. Three-year progression to AD was assessed (DSM-III-R criteria).

RESULTS

Occurrence per 100 nondemented persons of MCI-amnestic, MCI-multidomains, and MCI-single-nonmemory was 2.1%, 1.8%, and 7.2%, respectively. When applying modified definitions for MCI-amnestic and MCI-multidomains, the occurrence almost doubled. Seven percent of the sample had impairment on a global cognitive task but performed at normal levels on all other domain-specific tasks. MCI-multidomains showed the highest progression to AD (hazard ratio [HR]: 23.6, 9.3-60.1). MCI-amnestic reached similar predictivity only when using the modified definition (HR: 17.9, 6.8-46.9). Even participants without MCI who had only global deficits had a ninefold risk of AD (HR: 9.1, 2.8-29.4).

CONCLUSIONS

Two-thirds of MCI-multidomains, but only half of MCI-amnestic progress to AD. The standard MCI criteria failed to identify those people with global cognitive deficits who have, however, a high risk of progressing to AD.

Early symptoms and signs of cognitive deficits might not always be detectable in persons who develop Alzheimer's disease

OBJECTIVE

Clinical syndromes such as amnestic mild cognitive impairment (MCI) are highly predictive of future development of Alzheimer's disease (AD), but it is not known how many of the individuals that develop the disease can be identified with these syndromes. This study aims to determine how many individuals with AD show detectable symptoms or clinical signs of cognitive deficits three years before diagnosis.

METHODS

152 incident AD cases were identified in a dementia-free cohort of 1417 persons aged 75-95, after three-year follow-up from a prospective population-based study, the Kungsholmen Project. Symptoms of cognitive impairment including the subjective report of memory problems, and cognitive deficits were objectively measured with an extensive neuropsychological test battery at baseline. Incident AD was clinically diagnosed according to DSM-IIIR criteria at three-year follow-up.

RESULTS

Only half of future AD cases reported subjective memory problems three years before diagnosis. More than one-third of incident AD cases did not exhibit detectable deficits in any of the investigated specific cognitive domains. Only 38.3% had both subjective complaints and domain-specific cognitive deficits.

CONCLUSIONS

Symptoms and signs currently used to define MCI are not always present in persons who develop AD. Increasing the number of potentially identifiable and treatable preclinical AD cases is unfeasible unless more sensitive subjective and objective markers are identified. Furthermore, as only half of future AD cases report subjective memory problems three years before diagnosis, the number of persons coming to the attention of medical care is limited.

Longitudinal trajectories of cognitive change in preclinical Alzheimer's disease: a growth mixture modeling analysis

Preclinical Alzheimer's disease (AD) refers to a period of time prior to diagnosis during which cognitive deficits among individuals who will go on to receive a diagnosis of AD are present. There is great interest in describing the nature of cognitive change during the preclinical period, in terms of whether persons decline in a linear fashion to diagnosis, or exhibit some stability of functioning, followed by rapid losses in performance. In the current study we apply Growth Mixture Modeling to data from The Kungsholmen Project to evaluate whether decline in Mini Mental State Examination (MMSE) scores during the preclinical period of AD follows a linear or quadratic function. At the end of a 7-year follow-up period, some individuals would be diagnosed with AD (n=71), whereas others would remain free of dementia (n=457). The results indicated that a two-group quadratic model of decline provided the best statistical fit measures, as well as the greatest estimates of sensitivity (67%) and specificity (86%). Differences in MMSE scores were apparent at baseline, but the preclinical AD group began to experience precipitous declines three years prior to diagnosis. Finally, persons who were misclassified as preclinical AD had fewer years of education and poorer MMSE scores at baseline.

Behavioural measures in frontotemporal lobar dementia and other dementias: the utility of the frontal behavioural inventory and the neuropsychiatric inventory in a national cohort study

BACKGROUND

Distinguishing between patients with frontotemporal lobar dementia (FTLD) and other dementing illnesses remains a difficult task for many clinicians. In this study, we aimed to provide further evidence for the construct validity of the frontal behavioural inventory (FBI) and assess its utility in differentiating FTLD patients from other groups using data from the Canadian Collaborative Cohort of Related Dementias (ACCORD) study.

METHOD

Baseline scores on the FBI and neuropsychiatric inventory (NPI) were compared among several clinical groups (n = 177).

RESULTS

The FBI discriminated a higher percentage of FTLD patients (>75% correct classification) from Alzheimer's disease and other groups compared to the NPI (54.2%).

CONCLUSION

This study provides good evidence for convergent validity between the FBI and NPI (r = 0.72), indicating that both measures capture similar psychopathology in this nationwide cohort.

Time use and costs of institutionalised elderly persons with or without dementia: results from the Nordanstig cohort in the Kungsholmen Project--a population based study in Sweden

BACKGROUND

The aging of the population has become a worldwide phenomenon. This leads to increased demand for services and with limited resources it is important to find a way to estimate how resources can be match to those with greatest need.

AIMS

To analyse time use and costs in institutional care in relation to different levels of cognitive and functional capacity for elderly persons.

METHODS

The population consisted of all institutionalised inhabitants, 75 + years, living in a rural community (n = 176). They were clinically examined by physicians and interviewed by nurses. Staff and informal care-giving time was examined with the RUD (Resource Utilization in Dementia) instrument.

RESULTS

Tobit regression analyses showed that having dementia increased the amount of ADL care time with 0.9 h when compared to those not having dementia, whereas each loss of an ADL function (0-6) added 0.6 h of ADL care time. Analysing the total care time use, the presence of dementia added more than 9 h, while each loss of one ADL function added 2.9 h. There were some informal care contributions, however with no correlation to severity in dependency. The estimated cost for institutional care increased with more than 85% for people being dependent in 5-6 ADL activities compared to persons with no functional dependency, and with 30% for persons with dementia compared to the non-demented.

CONCLUSION

There is a variation in time use in institutional settings due to differences in ADL dependency but also whether dementia is present or not. This variation has implications for costs of institutional care.

The effect of borderline diabetes on the risk of dementia and Alzheimer's disease

To verify the hypothesis that borderline diabetes may increase the risk of dementia and Alzheimer's disease, a community-based cohort of 1,173 dementia- and diabetes-free individuals aged >or=75 years was longitudinally examined three times to detect patients with dementia and Alzheimer's disease (Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria). Borderline diabetes was defined as a random plasma glucose level of 7.8-11.0 mmol/l. Data were analyzed using Cox proportional hazards models. During the 9-year follow-up, 397 subjects developed dementia, including 307 Alzheimer's cases. At baseline, 47 subjects were identified with borderline diabetes. Borderline diabetes was associated with adjusted hazard ratios (95% CIs) of 1.67 (1.04-2.67) for dementia and 1.77 (1.06-2.97) for Alzheimer's disease; the significant associations were present after additional adjustment for future development of diabetes. Stratified analysis suggested a significant association between borderline diabetes and Alzheimer's disease only among noncarriers of APOE epsilon4 allele. There was an interaction between borderline diabetes and severe systolic hypertension on the risk of Alzheimer's disease (P = 0.04). We conclude that borderline diabetes is associated with increased risks of dementia and Alzheimer's disease; the risk effect is independent of the future development of diabetes. Borderline diabetes may interact with severe systolic hypertension to multiply the risk of Alzheimer's disease.

Rethinking the dementia diagnoses in a population-based study: what is Alzheimer's disease and what is vascular dementia? A study from the kungsholmen project

OBJECTIVE

To explore the hypothesis that older adults often are affected by more than one disease, making the differential diagnosis between Alzheimer's disease (AD) and vascular dementia (VaD) difficult.

METHODS

Incident dementia cases (n = 308) from a population-based longitudinal study of people 75+ years were investigated. The DSM-III-R criteria were used for the clinical diagnosis of dementia. Data on vascular disorders (hypertension, cerebrovascular and ischemic heart diseases, heart failure, atrial fibrillation, diabetes) as well as type of onset/course of dementia were used retrospectively to reclassify dementias.

RESULTS

Only 47% of the AD cases were reclassified as pure AD without any vascular disorder. Among subjects with AD and with a vascular component, cerebrovascular disease was the most common (41%). Only 25% of VaD were reclassified as pure VaD. Further, 26% of the pure AD subjects developed a vascular disorder in the following 3 years.

CONCLUSIONS

Both vascular and degenerative mechanisms may often contribute to the expression of dementia among the elderly. Most of the AD cases have vascular involvements, and pure dementia types in very old subjects constitute only a minority of dementia cases.

Patterns of prospective and retrospective memory impairment in preclinical Alzheimer's disease

Forty-six preclinical Alzheimer's disease (AD) participants and 188 nondemented control persons from the Kungsholmen Project (L. Bäckman et al., 2004) were compared on prospective memory (ProM) and retrospective memory (RetM) tasks 3 years before dementia diagnosis. The preclinical AD participants showed deficits in both ProM and RetM. Most interestingly, logistic regression analyses revealed that ProM made an independent contribution to the prediction of AD over and above that of RetM. This finding suggests that ProM and RetM tap partly different cognitive operations. Furthermore, within the ProM task, both the retrospective and prospective components were similarly impaired in preclinical AD. Within RetM, the preclinical AD participants were impaired on indices of encoding, storage (forgetting), and retrieval of information. Hence, the findings indicate a rather global episodic memory impairment in preclinical AD that cuts across type of memory assessed (ProM and RetM) as well as across different components of both the ProM and RetM tasks.

The amount of informal and formal care among non-demented and demented elderly persons-results from a Swedish population-based study

BACKGROUND

Developed countries are experiencing a dramatic increase in the proportion of elderly persons, as well as a progressive aging of the elderly population itself. Knowledge regarding the amount of formal and informal care and its interaction at population-based level is limited.

OBJECTIVES

To describe the amount of formal and informal care for non-demented and demented persons living at home in a population-based sample.

METHODS

The population consisted of all inhabitants, 75 + years, living in a rural community (n = 740). They were clinically examined by physicians and interviewed by nurses. Dementia severity was measured according to Washington University Clinical Dementia Rating Scale (CDR). Informal and formal care was examined with the RUD (Resource Utilization in Dementia) instrument.

RESULTS

The amount of informal care was much greater than formal care and also greater among demented than non-demented. There was a relationship between the severity of the cognitive decline and the amount of informal care while this pattern was weaker regarding formal care. Tobit regression analyses showed a clear association between the number of hours of informal and formal care and cognitive decline although this pattern was much stronger for informal than formal care.

CONCLUSIONS

Informal care substitutes rather than compliments formal care and highlights the importance of future studies in order to truly estimate the amount of informal and formal care and the interaction between them. This knowledge will be of importance when planning the use of limited resources, and when supporting informal carers in their effort to care for their intimates.

Electroencephalogram in the dementia workup

Dementia is affecting an increasing proportion of the population in the developed world. It is important to reach a correct diagnosis of dementia, because this has implications on the treatment. The electroencephalogram (EEG) is, in general, not a sensitive test for detecting dementia and is not recommended in the standard workup of dementia. In spite of this, however, EEG is useful in patients with deteriorating mental status in whom dementia is suspected mainly to rule out delirium, depression, atypical complex partial seizures, and prion disease. An EEG also provides insight into the physiology of different dementia types. The EEG is most useful when interpreted within a well-defined clinical context, such as knowing the patient's degree of cognitive impairment. It is a noninvasive and inexpensive test, and the threshold should be low for ordering it. This article summarizes EEG findings with aging, different dementia types, and conditions masked as dementia.

Complete ascertainment of dementia in the Swedish Twin Registry: the HARMONY study

The purpose of this report is to describe the Study of Dementia in Swedish Twins (known as HARMONY), including procedures for complete ascertainment of all cases of Alzheimer's disease (AD) and other dementias in 14,435 individuals aged 65 and older from the national Swedish twin registry. Telephone cognitive screening identified 11.5% as positive for cognitive dysfunction. Clinical diagnoses were completed for 1557 individuals, including individuals who screened positive, their twin partners, and a sample of normal controls. Estimated prevalence of dementia ranged from 1.4% for age 65-69 to 29.2% for age 90 and older. Concordance rates for Alzheimer's disease were 59% for monozygotic twins, 32% for like-sexed, and 24% for unlike-sexed dizygotic twins. Among monozygotic twins where both twins had Alzheimer's disease, the within pair difference in age of onset ranged from both becoming demented in the same year to 7 years difference in onset.

A preclinical phase in vascular dementia: cognitive impairment three years before diagnosis

Alzheimer's disease (AD) and vascular dementia (VaD) patients exhibit similar patterns of deficits in many cognitive tasks in the early clinical stages. Considering that preclinical cognitive deficits are well documented in AD, the purpose of the present study was to investigate if such deficits are also present in VaD. The cognitive outcome measure was the Mini-Mental State Examination (MMSE). The sample was taken from a population-based study and consisted of 699 persons who were nondemented at baseline, but out of whom 35 persons were diagnosed with VaD and 170 with AD at a 3-year follow-up. Both the incident VaD and AD cases exhibited baseline deficits on the total score of the MMSE and three of the subscales: orientation to time, orientation to place, and delayed memory. Further, both dementia groups exhibited precipitous decline on most MMSE subscales during the 3-year follow-up period. Logistic regression analyses showed that all subscales that revealed deficits at baseline predicted dementia status at follow-up. Delayed memory was the best predictor in both preclinical VaD and preclinical AD. Thus, these results demonstrate preclinical cognitive deficits in VaD in a measure of global cognitive functioning, which closely resemble those observed in AD. This observation suggests that circulatory disturbance is associated with cognitive problems several years before the actual VaD diagnosis.

Occupational exposure to electromagnetic fields and risk of Alzheimer's disease

BACKGROUND

Extremely-low-frequency magnetic field (ELF-MF) exposure is suspected to increase the risk of Alzheimer's disease. Such fields are present in the vicinity of electrical motors and other electric appliances containing coils.

METHODS

We investigated lifetime occupational ELF-MF exposure in relation to Alzheimer's disease and dementia among a community dementia-free cohort (n = 931) age 75 years and older in Stockholm, Sweden. This cohort was followed from 1987-1989 until 1994-1996 to detect dementia cases (Diagnostic and Statistical Manual of Mental Disorders, revised 3rd edition criteria). Information on lifetime job history was obtained by interview, usually of next of kin. ELF-MF exposure was assessed using a job-exposure matrix, measurement on historical equipment, and expert estimation. We analyzed the data with Cox models controlling for potential confounders.

RESULTS

Dementia was diagnosed in 265 subjects, including 202 with Alzheimer's disease. Among men, ELF-MF exposure > or=0.2 microT in lifetime principal job was related to multivariate-adjusted relative risks of 2.3 (95% CI = 1.0-5.1) for Alzheimer's disease and 2.0 (1.1-3.7) for dementia. We found no association among women. A similar sex-specific pattern was seen for the associations with average ELF-MF exposure throughout the work life. A dose-response relation was suggested in men, with multivariate-adjusted relative risks of 2.4 (0.8-6.8) for Alzheimer's disease and 2.5 (1.1-5.6) for dementia for the upper tertile of lifetime average exposure.

CONCLUSIONS

Long-term occupational exposure to a higher ELF-MF level may increase the risk of Alzheimer's disease and dementia in men. Similar patterns were not seen in women, which may in part be the result of a greater exposure misclassification in women than in men.