The challenge of dementia prevention trials and the role of quasi-experimental studies.

Observational studies have shown consistently that modifiable risk factors during life are associated with increased dementia risk in old age but randomized controlled trials (RCTs) on dementia prevention evaluating the treatment of these risk factors did not find consistent effects on cognitive outcomes. The discrepancy in findings is potentially attributable to inherent differences between the two study designs. Although RCTs are the gold standard for establishing causality, designing and conducting an RCT for dementia prevention is complex. Quasi-experimental studies (QESs) may contribute to investigating causality without randomization. QESs use variation in exposure to a risk factor or intervention in an observational setting to deduct causal effects. Design-specific approaches are used to control for confounding, the main caveat of QESs. In this article we address the challenges, opportunities, and limitations of QESs for research into dementia prevention. HIGHLIGHTS: Despite consistent associations between modifiable risk factors and dementia, the mostly neutral effects of randomized controlled trials (RCTs) challenge the causality of these associations. RCTs in the field of dementia prevention are often problematic due to ethical, practical, or financial constraints, and their results may have limited generalizability. Four quasi-experimental study (QES) designs may be suitable to study causality between risk factors and dementia; we critically appraise these study designs for dementia-prevention studies. We describe how specific QES designs can be used to study the effects of risk-factor modification for 12 known risk factors for dementia.

Microglial cell response in α7 nicotinic acetylcholine receptor-deficient mice after systemic infection with Escherichia coli.

BACKGROUND: Development of neurodegeneration in older people has been associated with microglial cell activation triggered by systemic infection. We hypothesize that α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulation of this process. METHODS: 8- to 10-week-old male wild-type (WT) and α7nAChR knock-out (α7nAChR-/-) mice were intraperitoneally inoculated with live Escherichia (E.) coli or saline. After inoculation, all mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 h and killed at 2 or 3 days. The microglial response was characterized by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry. To quantify inflammatory response, mRNA expression of pro- and anti-inflammatory mediators was measured in brain and spleen. RESULTS: We observed no differences in Iba-1 positive cell number or morphology and flow cytometry (CD11b, CD45 and CD14) of microglial cells between WT and α7nAChR-/- mice after systemic infection. Infected α7nAChR-/- mice showed significantly higher mRNA expression in brain for tumor necrosis factor alpha (TNF-α) at day 2 and 3, interleukin 6 (IL-6) at day 2 and monocyte chemotactic protein 1 (MCP-1) and suppressor of cytokine signaling 1 (SOCS1) at day 3, there was significantly lower mRNA expression in brain for mitogen-activated protein kinase 1 (MAPK1) at day 2 and 3, high-mobility group 1 (HMGB-1) and CD11b at day 2, and deubiquitinase protein A20 (A20) at day 3 compared to infected WT mice. INTERPRETATION: Loss of function of α7nAChR during systemic infection led to an increased expression of TNF-α and IL-6 in brain after systemic infection with E. coli, but not to distinct differences in microglial cell number or morphological activation of microglia.

Diagnostic Accuracy of the Telephone Interview for Cognitive Status for the Detection of Dementia in Primary Care.

PURPOSE: Cognitive diagnostic work-up in primary care is not always physically feasible, owing to chronic disabilities and/or travel restrictions. The identification of dementia might be facilitated with diagnostic instruments that are time efficient and easy to perform, as well as useful in the remote setting. We assessed whether the Telephone Interview for Cognitive Status (TICS) might be a simple and accurate alternative for remote diagnostic cognitive screening in primary care. METHODS: We administered the TICS (range, 0-41) for 810 of 1,473 older people aged 84.5 (SD, 2.4) years. We scrutinized electronic health records for participants with TICS scores ≤30 and for a random sample of participants with TICS scores >30 for a dementia diagnosis using all data from the Prevention of Dementia by Intensive Vascular Care (preDIVA) trial for 8-12 years of follow-up. We used multiple imputation to correct for verification bias. RESULTS: Of the 810 participants, 155 (19.1%) had a TICS score ≤30, and 655 (80.9%) had a TICS score >30. Electronic health records yielded 8.4% (13/154) dementia diagnoses for participants with TICS ≤30 vs none with TICS >30. Multiple imputation for TICS >30 yielded a median of 7/655 (1.1%; interquartile range, 5-8) estimated dementia cases. After multiple imputation, the optimal cutoff score was ≤29, with mean sensitivity 65.4%, specificity 87.8%, positive predictive value 11.9%, negative predictive value 99.0%, and area under the curve 77.4% (95% CI, 56.3%-90.0%). CONCLUSIONS: In the present older population, the TICS performed well as a diagnostic screening instrument for excluding dementia and might be particularly useful when face-to-face diagnostic screening is not feasible in family practice or research settings. The potential reach to large numbers of people at low cost could contribute to more efficient medical management in primary care.

Bayes analysis supports null hypothesis of anti-amyloid beta therapy in Alzheimer's disease.

Numerous clinical trials of anti-amyloid beta (Aß) immunotherapy in Alzheimer's disease have been performed. None of these have provided convincing evidence for beneficial effects. Using traditional frequentist meta-analysis, the conclusion is that there is absence of evidence for a therapeutic effect, with a point estimate effect size of 0.05 (95% confidence interval -0.00 to 0.10, P = .055). In addition, this non-significant effect equates to 0.4 points per year on the cognitive subscale of the Alzheimer's Disease Assessment Scale. This is well below the minimally clinically important difference. Bayesian meta-analysis of these trial data provides strong evidence of absence of a therapeutic effect, with a Bayes factor of 11.27 in favor of the null hypothesis, opposed to a Bayes factor of 0.09 in favor of a treatment effect. Bayesian analysis is particularly valuable in this context of repeatedly reported small, non-significant effect sizes in individual trials. Mechanisms other than removal of Aß from the brain may be probed to slow progression of Alzheimer's disease.

Preoperative Cerebrospinal Fluid Cortisol and the Risk of Postoperative Delirium: A Prospective Study of Older Hip Fracture Patients.

BACKGROUND: Ageing, depression, and neurodegenerative disease are common risk factors for delirium in the elderly. These risk factors are associated with dysregulation of the hypothalamic-pituitary-adrenal axis, resulting in higher levels of cortisol under normal and stressed conditions and a slower return to baseline. OBJECTIVES: We investigated whether elevated preoperative cerebrospinal fluid (CSF) cortisol levels are associated with the onset of postoperative delirium. METHODS: In a prospective cohort study CSF samples were collected after cannulation for the introduction of spinal anesthesia of 75 patients aged 75 years and older admitted for surgical repair of acute hip fracture. Delirium was assessed with the confusion assessment method (CAM) and the Delirium Rating Scale-Revised-98 (DRS-R98). Because the CAM and DRS-R98 were available for time of admission and 5 postoperative days, we used generalized estimating equations and linear mixed modeling to examine the association between preoperative CSF cortisol levels and the onset of postoperative delirium. RESULTS: Mean age was 83.5 (SD 5.06) years, and prefracture cognitive decline was present in one-third of the patients (24 [33%]). Postoperative delirium developed in 27 (36%) patients. We found no association between preoperative CSF cortisol levels and onset or severity of postoperative delirium. CONCLUSIONS: These findings do not support the hypothesis that higher preoperative CSF cortisol levels are associated with the onset of postoperative delirium in elderly hip fracture patients.

Associations of Subjective Memory Complaints and Simple Memory Task Scores With Future Dementia in the Primary Care Setting.

PURPOSE: Family physicians need simple yet comprehensive algorithms to discriminate between community-dwelling older persons who are at increased risk of dementia and those who are not. We aimed to investigate associations between incident dementia and responses to a single question regarding subjective memory complaints (SMC) combined with scores on 2 simple memory tests that are easy to use in the primary care setting. METHODS: Analyses were based on data from 3,454 community-dwelling older persons who participated in the 6- to 8-year Prevention of Dementia by Intensive Vascular Care (preDIVA) trial, yielding 21,341 person-years of observation. Participants were considered a single cohort. We used Cox models to assess separate and combined associations of SMC, an imperfect score on the Mini-Mental State Examination delayed recall item (MMSE-5), and an imperfect score on the Visual Association Test (VAT) with future dementia. RESULTS: Subjective memory complaints alone were associated with future dementia (hazard ratio [HR] = 3.01; 95% CI, 2.31-3.94; P <.001), as were the MMSE-5 (HR = 2.14; 95% CI, 1.59-2.87; P <.001) and VAT (HR = 3.19; 95% CI, 2.46-4.13; P <.001) scores. After a median follow-up of 6.7 years, the occurrence of dementia ranged from 4% to 30% among persons with SMC, depending on the MMSE-5 and VAT scores. These test scores did not substantially alter the association with future dementia for persons without SMC. CONCLUSIONS: In persons with SMC, the strength of the association between future dementia and an imperfect MMSE-5 score depends substantially on the VAT score.

The trajectory of C-reactive protein serum levels in older hip fracture patients with postoperative delirium.

OBJECTIVES: Important precipitating risk factors for delirium such as infections, vascular disorders, and surgery are accompanied by a systemic inflammatory response. Systemic inflammatory mediators can induce delirium in susceptible individuals. Little is known about the trajectory of systemic inflammatory markers and their role in the development and outcome of delirium. METHODS: This is a prospective cohort study of older patients undergoing acute surgery for hip fracture. Baseline characteristics were assessed preoperatively. During hospital admission, presence of delirium was assessed daily according to the Confusion Assessment Method criteria. This study compared the trajectory of serum levels of the C-reactive protein (CRP) between people with and without postoperative delirium. Blood samples were taken at baseline and at postoperative day 1 through postoperative day 5. RESULTS: Forty-one out of 121 patients developed postoperative delirium after hip fracture surgery. Longitudinal analysis of the trajectory of serum CRP levels using the Generalized Estimating Equations (GEE) method identified that higher CRP levels were associated with postoperative delirium. CRP levels were higher from postoperative day 2 through postoperative day 5. No significant differences in serum CRP levels were found when we compared patients with short (1-2 days) and more prolonged delirium (3 days or more). CONCLUSIONS: Delirium is associated with an increased systemic inflammatory response, and our results suggest that CRP plays a role in the underlying (inflammatory-vascular) pathological pathway of postoperative delirium.

A network approach on the relation between apathy and depression symptoms with dementia and functional disability.

BACKGROUND: Studies on the association between depression and dementia risk mostly use sum scores on depression questionnaires to model symptomatology severity. Since individual items may contribute differently to this association, this approach has limited validity. METHODS: We used network analysis to investigate the functioning of individual Geriatric Depression Scale (GDS-15) items, of which, based on studies that used factor analysis, 3 are generally considered to measure apathy (GDS-3A) and 12 depression (GDS-12D). Functional disability and future dementia were also included in our analysis. Data were extracted from 3229 participants of the Prevention of Dementia by Intensive Vascular care trial (preDIVA), analyzed as a single cohort, yielding 20,542 person-years of observation. We estimated a sparse network by only including connections between variables that could not be accounted for by variance in other variables. For this, we used a repeated L1 regularized regression procedure. RESULTS: This procedure resulted in a selection of 59/136 possible connections. GDS-3A items were strongly connected to each other and with varying strength to several GDS-12D items. Functional disability was connected to all three GDS-3A items and the GDS-12D items "helplessness" and "worthlessness". Future dementia was only connected to the GDS-12D item "memory problems", which was in turn connected to the GDS-12D items "unhappiness" and "helplessness" and all three GDS-3A items. CONCLUSION: Network analysis reveals interesting relationships between GDS items, functional disability and dementia risk. We discuss what implications our results may have for (future) research on the associations between depression and/or apathy with dementia.

Performance on bedside tests of attention and organized thinking in patients with dementia free from delirium.

ABSTRACTObjectives:Bedside tests of attention and organized thinking were performed in patients with cognitive impairment or dementia but without delirium, to provide estimates of false positive rates for detecting delirium superimposed on dementia (DSD). DESIGN AND SETTING: This cross-sectional study was conducted in outpatients and institutionalized patients without delirium representing a wide spectrum of severity of cognitive impairments. PARTICIPANTS: Patients with dementia or a cognitive disorder according to DSM IV criteria, after exclusion of (suspected) delirium according to DSM IV criteria. MEASUREMENTS: Tests for inattention and disorganized thinking from the CAM-ICU were assessed. RESULTS: The sample included 163 patients (mean age 83 years (SD 6; 64% women)), with Alzheimer's disease as most prevalent (45%) diagnosis and a mean MMSE-score of 16.8 (SD 7.5). False positive rates of the test of attention varied from 0.04 in patients with normal to borderline cognitive function to 0.8 in those with severe dementia. The false positive rate of the test of disorganized thinking was zero in the normal to borderline group, increasing to 0.67 in patients with severe dementia. When combining test results false positive rates decreased to 0.03 in patients with MMSE scores above 9. CONCLUSION: Use of simple bedside tests of attention and organized thinking for the clinical diagnosis of DSD will result in high rates of false positive observations if used regardless of the severity of dementia. However, if test results are combined they may be useful to exclude DSD in patients with minimal to moderate degrees of dementia, but not in the severe group.

Improving Prediction of Dementia in Primary Care.

PURPOSE: The Mini-Mental State Examination (MMSE) is one of the most widely used instruments to screen for cognitive deficits; however, this instrument alone is not sensitive enough to detect early symptoms of dementia. We aimed to investigate whether additionally using the Visual Association Test (VAT) improves the predictive value of the MMSE score for development of dementia. METHODS: Analyses were based on data from 2,690 primary care patients aged 70 to 78 years who participated in the Prevention of Dementia by Intensive Vascular Care (preDIVA) trial. We assessed change in the 30-point MMSE score over 2 years and the VAT score at 2 years-dichotomized as perfect (6 points) or imperfect (≤5 points)-and evaluated the predictive values of these tests for a diagnosis of dementia in the subsequent 4 to 6 years. Data were analyzed with logistic regression analysis. RESULTS: Patients having a decline of 2 points or more in total MMSE score over 2 years had an odds ratio of 3.55 (95% CI, 2.51-5.00) for developing dementia. Patients having the same decline in MMSE score plus an imperfect VAT score had an odds ratio of 9.55 (95% CI, 5.89-15.41) for developing dementia. A 1-point decline in MMSE score increased odds of dementia only when the VAT score was imperfect. Dementia risk for patients with a 2- or 3-point decrease in MMSE score and a perfect VAT score did not differ significantly from the average risk of the cohort as a whole. CONCLUSIONS: Administering the VAT in patients with a small decline on the MMSE over a 2-year period has substantial incremental value for identifying those at elevated risk for developing dementia. This simple test may help distinguish older adults who need further cognitive examination from those in whom a watchful waiting policy is justified.

Effect of Long-Term Vascular Care on Progression of Cerebrovascular Lesions: Magnetic Resonance Imaging Substudy of the PreDIVA Trial (Prevention of Dementia by Intensive Vascular Care).

BACKGROUND AND PURPOSE: This study aimed to evaluate the effect of a nurse-led multidomain cardiovascular intervention on white matter hyperintensity (WMH) progression and incident lacunar infarcts in community-dwelling elderly with hypertension. METHODS: The preDIVA trial (Prevention of Dementia by Intensive Vascular Care) was an open-label, cluster-randomized controlled trial in community-dwelling individuals aged 70 to 78 years. General practices were assigned by computer-generated randomization to 6-year nurse-led, multidomain intensive vascular care or standard care. Of 3526 preDIVA participants, 195 nondemented participants with a systolic blood pressure ≥140 mm Hg were consecutively recruited to undergo magnetic resonance imaging at 2 to 3 and 5 to 6 years after baseline. WMH volumes were measured automatically, lacunar infarcts assessed visually, blinded to treatment allocation. RESULTS: One hundred and twenty-six participants were available for longitudinal analysis (64 intervention and 62 control). Annual WMH volume increase in milliliter was similar for intervention (mean=0.73, SD=0.84) and control (mean=0.70, SD=0.59) participants (adjusted mean difference, -0.08 mL; 95% confidence interval, -0.30 to 0.15; P=0.50). Analyses suggested greater intervention effects with increasing baseline WMH volumes (P for interaction=0.03). New lacunar infarcts developed in 6 (9%) intervention and 2 (3%) control participants (odds ratio, 2.2; 95% confidence interval, 0.4-12.1; P=0.36). CONCLUSIONS: Nurse-led vascular care in hypertensive community-dwelling older persons did not diminish WMH accumulation over 3 years. However, our results do suggest this type of intervention could be effective in persons with high WMH volumes. There was no effect on lacunar infarcts incidence but numbers were low. CLINICAL TRIAL INFORMATION: URL: http://www.isrctn.com/ISRCTN29711771. Unique identifier: ISRCTN29711771.

Dementia incidence trend over 1992-2014 in the Netherlands: Analysis of primary care data.

BACKGROUND: Recent reports have suggested declining age-specific incidence rates of dementia in high-income countries over time. Improved education and cardiovascular health in early age have been suggested to be bringing about this effect. The aim of this study was to estimate the age-specific dementia incidence trend in primary care records from a large population in the Netherlands. METHODS AND FINDINGS: A dynamic cohort representative of the Dutch population was composed using primary care records from general practice registration networks (GPRNs) across the country. Data regarding dementia incidence were obtained using general-practitioner-recorded diagnosis of dementia within the electronic health records. Age-specific dementia incidence rates were calculated for all persons aged 60 y and over; negative binomial regression analysis was used to estimate the time trend. Nine out of eleven GPRNs provided data on more than 800,000 older people for the years 1992 to 2014, corresponding to over 4 million person-years and 23,186 incident dementia cases. The annual growth in dementia incidence rate was estimated to be 2.1% (95% CI 0.5% to 3.8%), and incidence rates were 1.08 (95% CI 1.04 to 1.13) times higher for women compared to men. Despite their relatively low numbers of person-years, the highest age groups contributed most to the increasing trend. There was no significant overall change in incidence rates since the start of a national dementia program in 2003 (-0.025; 95% CI -0.062 to 0.011). Increased awareness of dementia by patients and doctors in more recent years may have influenced dementia diagnosis by general practitioners in electronic health records, and needs to be taken into account when interpreting the data. CONCLUSIONS: Within the clinical records of a large, representative sample of the Dutch population, we found no evidence for a declining incidence trend of dementia in the Netherlands. This could indicate true stability in incidence rates, or a balance between increased detection and a true reduction. Irrespective of the exact rates and mechanisms underlying these findings, they illustrate that the burden of work for physicians and nurses in general practice associated with newly diagnosed dementia has not been subject to substantial change in the past two decades. Hence, with the ageing of Western societies, we still need to anticipate a dramatic absolute increase in dementia occurrence over the years to come.

Effectiveness of a 6-year multidomain vascular care intervention to prevent dementia (preDIVA): a cluster-randomised controlled trial.

BACKGROUND: Cardiovascular risk factors are associated with an increased risk of dementia. We assessed whether a multidomain intervention targeting these factors can prevent dementia in a population of community-dwelling older people. METHODS: In this open-label, cluster-randomised controlled trial, we recruited individuals aged 70-78 years through participating general practices in the Netherlands. General practices within each health-care centre were randomly assigned (1:1), via a computer-generated randomisation sequence, to either a 6-year nurse-led, multidomain cardiovascular intervention or control (usual care). The primary outcomes were cumulative incidence of dementia and disability score (Academic Medical Center Linear Disability Score [ALDS]) at 6 years of follow-up. The main secondary outcomes were incident cardiovascular disease and mortality. Outcome assessors were masked to group assignment. Analyses included all participants with available outcome data. This trial is registered with ISRCTN, number ISRCTN29711771. FINDINGS: Between June 7, 2006, and March 12, 2009, 116 general practices (3526 participants) within 26 health-care centres were recruited and randomly assigned: 63 (1890 participants) were assigned to the intervention group and 53 (1636 participants) to the control group. Primary outcome data were obtained for 3454 (98%) participants; median follow-up was 6·7 years (21 341 person-years). Dementia developed in 121 (7%) of 1853 participants in the intervention group and in 112 (7%) of 1601 participants in the control group (hazard ratio [HR] 0·92, 95% CI 0·71-1·19; p=0·54). Mean ALDS scores measured during follow-up did not differ between groups (85·7 [SD 6·8] in the intervention group and 85·7 [7·1] in the control group; adjusted mean difference -0·02, 95% CI -0·38 to 0·42; p=0·93). 309 (16%) of 1885 participants died in the intervention group, compared with 269 (16%) of 1634 participants in the control group (HR 0·98, 95% CI 0·80-1·18; p=0·81). Incident cardiovascular disease did not differ between groups (273 [19%] of 1469 participants in the intervention group and 228 [17%] of 1307 participants in the control group; HR 1·06, 95% CI 0·86-1·31; p=0·57). INTERPRETATION: A nurse-led, multidomain intervention did not result in a reduced incidence of all-cause dementia in an unselected population of older people. This absence of effect might have been caused by modest baseline cardiovascular risks and high standards of usual care. Future studies should assess the efficacy of such interventions in selected populations. FUNDING: Dutch Ministry of Health, Welfare and Sport; Dutch Innovation Fund of Collaborative Health Insurances; and Netherlands Organisation for Health Research and Development.

Severe Infections are Common in Thiamine Deficiency and May be Related to Cognitive Outcomes: A Cohort Study of 68 Patients With Wernicke-Korsakoff Syndrome.

BACKGROUND: Wernicke encephalopathy can have different clinical outcomes. Although infections may precipitate the encephalopathy itself, it is unknown whether infections also modify the long-term outcome in patients developing Korsakoff syndrome. OBJECTIVE: To determine whether markers of infection, such as white blood cell (WBC) counts and absolute neutrophil counts in the Wernicke phase, are associated with cognitive outcomes in the end-stage Korsakoff syndrome. METHOD: Retrospective, descriptive study of patients admitted to Slingedael Korsakoff Center, Rotterdam, The Netherlands. Hospital discharge letters of patients with Wernicke encephalopathy were searched for relevant data on infections present upon hospital admission. Patients were selected for further analysis if data were available on WBC counts in the Wernicke phase and at least 1 of 6 predefined neuropsychological tests on follow-up. RESULTS: Infections were reported in 35 of 68 patients during the acute phase of Wernicke-Korsakoff syndrome-meningitis (1), pneumonia (14), urinary tract infections (9), acute abdominal infections (4), sepsis (5) empyema, (1) and infection "of unknown origin" (4). The neuropsychological test results showed significant lower scores on the Cambridge Cognitive Examination nonmemory section with increasing white blood cell counts (Spearman rank correlation, ρ = -0.34; 95% CI: -0.57 to -0.06; 44 patients) and on the "key search test" of the behavioral assessment of the dysexecutive syndrome with increasing absolute neutrophil counts (ρ= -0.85; 95% CI: -0.97 to -0.42; 9 patients). CONCLUSIONS: Infections may be the presenting manifestation of thiamine deficiency. Patients with Wernicke-Korsakoff syndrome who suffered from an infection during the acute phase are at risk of worse neuropsychological outcomes on follow-up.

The mediating role of cardiovascular risk factors in the relationship between symptoms of apathy and incident cardiovascular disease in community-dwelling older individuals.

BACKGROUND: In old age, both apathy and depression have been associated with an increased cardiovascular disease (CVD) risk. This study evaluated the mediating role of cardiovascular risk factors in the relationship of apathy and mood symptoms with incident CVD. METHODS: Prospective cohort study of 1,790 community-dwelling older individuals (70-78 years) without a history of CVD or stroke. At baseline, apathy and mood symptoms were assessed with the 15-item Geriatric Depression Scale (GDS-15), of which three items represent apathy symptoms. The mediational risk factors included were diabetes mellitus (DM), body mass index (BMI), current smoking, physical inactivity, systolic blood pressure, and total cholesterol. Incident CVD was evaluated after two years of follow-up. Data were analyzed using structural equation modeling (SEM). RESULTS: Incident CVD occurred in 59 (3.3%) participants. Apathy symptoms had a significant estimated total effect on incident CVD, with increases of 2.2% for each unit increase in apathy score. Of this total effect, 22.7% was due to the mediational effects of physical inactivity (13.6%), current smoking (4.5%), and DM (4.5%). The remaining 77.3% was due to direct effects reflecting other mediational dynamics. No significant (in)direct effects of mood symptoms on incident CVD were found. CONCLUSIONS: Physical inactivity, smoking, and DM account for nearly one-fourth of the variation reflecting the link between apathy symptoms and incident CVD. This illustrates the relevance of unfavorable health behaviors and assessment of DM in older individuals with apathy. The majority of the effect of apathy symptoms on incident CVD is caused by other, yet unknown, factors.

Web-Based Interventions Targeting Cardiovascular Risk Factors in Middle-Aged and Older People: A Systematic Review and Meta-Analysis.

BACKGROUND: Web-based interventions can improve single cardiovascular risk factors in adult populations. In view of global aging and the associated increasing burden of cardiovascular disease, older people form an important target population as well. OBJECTIVE: In this systematic review and meta-analysis, we evaluated whether Web-based interventions for cardiovascular risk factor management reduce the risk of cardiovascular disease in older people. METHODS: Embase, Medline, Cochrane and CINAHL were systematically searched from January 1995 to November 2014. Search terms included cardiovascular risk factors and diseases (specified), Web-based interventions (and synonyms) and randomized controlled trial. Two authors independently performed study selection, data-extraction and risk of bias assessment. In a meta-analysis, outcomes regarding treatment effects on cardiovascular risk factors (blood pressure, glycated hemoglobin A1c (HbA1C), low-density lipoprotein (LDL) cholesterol, smoking status, weight and physical inactivity) and incident cardiovascular disease were pooled with random effects models. RESULTS: A total of 57 studies (N=19,862) fulfilled eligibility criteria and 47 studies contributed to the meta-analysis. A significant reduction in systolic blood pressure (mean difference -2.66 mmHg, 95% CI -3.81 to -1.52), diastolic blood pressure (mean difference -1.26 mmHg, 95% CI -1.92 to -0.60), HbA1c level (mean difference -0.13%, 95% CI -0.22 to -0.05), LDL cholesterol level (mean difference -2.18 mg/dL, 95% CI -3.96 to -0.41), weight (mean difference -1.34 kg, 95% CI -1.91 to -0.77), and an increase of physical activity (standardized mean difference 0.25, 95% CI 0.10-0.39) in the Web-based intervention group was found. The observed effects were more pronounced in studies with short (<12 months) follow-up and studies that combined the Internet application with human support (blended care). No difference in incident cardiovascular disease was found between groups (6 studies). CONCLUSIONS: Web-based interventions have the potential to improve the cardiovascular risk profile of older people, but the effects are modest and decline with time. Currently, there is insufficient evidence for an effect on incident cardiovascular disease. A focus on long-term effects, clinical endpoints, and strategies to increase sustainability of treatment effects is recommended for future studies.

Cortical microinfarcts detected in vivo on 3 Tesla MRI: clinical and radiological correlates.

BACKGROUND AND PURPOSE: Cortical microinfarcts (CMIs) are a common postmortem finding associated with vascular risk factors, cognitive decline, and dementia. Recently, CMIs identified in vivo on 7 Tesla MRI also proved retraceable on 3 Tesla MRI. METHODS: We evaluated CMIs on 3 Tesla MRI in a population-based cohort of 194 nondemented older people (72-80 years) with systolic hypertension. Using a case-control design, participants with and without CMIs were compared on age, sex, cardiovascular risk factors, and white matter hyperintensity volume. RESULTS: We identified 23 CMIs in 12 participants (6%). CMIs were associated with older age, higher diastolic blood pressure, and a history of recent stroke. There was a trend for a higher white matter hyperintensity volume in participants with CMIs. CONCLUSIONS: We found an association of CMIs with clinical parameters, including age and cardiovascular risk factors. Although the prevalence of CMIs is relatively low, our results suggest that the study of CMIs in larger clinical studies is possible using 3 Tesla MRI. This opens the possibility of large-scale prospective investigation of the clinical relevance of CMIs in older people.

Systemic inflammation and microglial activation: systematic review of animal experiments.

BACKGROUND: Animal studies show that peripheral inflammatory stimuli may activate microglial cells in the brain implicating an important role for microglia in sepsis-associated delirium. We systematically reviewed animal experiments related to the effects of systemic inflammation on the microglial and inflammatory response in the brain. METHODS: We searched PubMed between January 1, 1950 and December 1, 2013 and Embase between January 1, 1988 and December 1, 2013 for animal studies on the influence of peripheral inflammatory stimuli on microglia and the brain. Identified studies were systematically scored on methodological quality. Two investigators extracted independently data on animal species, gender, age, and genetic background; number of animals; infectious stimulus; microglial cells; and other inflammatory parameters in the brain, including methods, time points after inoculation, and brain regions. RESULTS: Fifty-one studies were identified of which the majority was performed in mice (n = 30) or in rats (n = 19). Lipopolysaccharide (LPS) (dose ranging between 0.33 and 200 mg/kg) was used as a peripheral infectious stimulus in 39 studies (76 %), and live or heat-killed pathogens were used in 12 studies (24 %). Information about animal characteristics such as species, strain, sex, age, and weight were defined in 41 studies (80 %), and complete methods of the disease model were described in 35 studies (68 %). Studies were also heterogeneous with respect to methods used to assess microglial activation; markers used mostly were the ionized calcium binding adaptor molecule-1 (Iba-1), cluster of differentiation 68 (CD68), and CD11b. After LPS challenge microglial activation was seen 6 h after challenge and remained present for at least 3 days. Live Escherichia coli resulted in microglial activation after 2 days, and heat-killed bacteria after 2 weeks. Concomitant with microglial response, inflammatory parameters in the brain were reviewed in 23 of 51 studies (45 %). Microglial activation was associated with an increase in Toll-like receptor (TLR-2 and TLR-4), tumor necrosis factor alpha (TNF-α), and interleukin 1 beta (IL-1ß) messenger ribonucleic acid (mRNA) expression or protein levels. INTERPRETATION: Animal experiments robustly showed that peripheral inflammatory stimuli cause microglial activation. We observed distinct differences in microglial activation between systemic stimulation with (supranatural doses) LPS and live or heat-killed bacteria.

Apathy in Parkinson's disease: A systematic review and meta-analysis.

Apathy is a frequently reported neuropsychiatric symptom in Parkinson's disease (PD), but its prevalence and clinical correlates are debated. We aimed to address these issues by conducting a systematic review and meta-analysis. Embase, Medline/PubMed, and PsychINFO databases were searched for relevant studies. Data were extracted by two independent observers, using predefined extraction forms tailored specifically to the research question. From 1,702 titles and abstracts, 23 studies were selected. Meta-analysis showed a prevalence of apathy in PD of 39.8% (n = 5,388, 905% CI 34.6-45.0%). Apathy was associated with higher age (3.3 years, 95% CI = 1.7-4.9), lower mean Mini-Mental State Evaluation (MMSE) score (-1.4 points, 95% CI = -2.1 to -0.8), an increased risk of co-morbid depression (relative risk [RR] = 2.3, 95% CI = 1.9-2.8), higher Unified Parkinson's Disease Rating Scale (UPDRS) motor score (6.5 points, 95% CI = 2.6-10.3), and more severe disability (Hedges-G = 0.5, 95% CI = 0.3-0.6). Half of the patients with apathy had concomitant depression (57.2%, 95% CI = 49.4-64.9%), and this estimate was similar after exclusion of patients with cognitive impairment (52.5%, 95% CI = 42.2%-62.8%). In conclusion, we found that apathy affects almost 40% of patients with PD. Several factors influence reported prevalence rates, contributing to the considerable heterogeneity in study results. Half of patients with apathy do not suffer from concomitant depression or cognitive impairment, confirming its status as a separate clinical syndrome in PD. The pervasiveness of apathy in PD warrants research into its treatment, although different underlying pathophysiological mechanisms may require different treatment strategies. Treatment of apathy could improve patient quality of life, reduce caregiver burden, alleviate disability by increasing motivation for self-care, and reduce cognitive impairment by improving executive functioning.