Metabolic Syndrome,Mild Cognitive Impairment,and Dementia: A Meta-Analysis of Longitudinal Studies

ObjectiveA systematic review and a meta-analysis of both clinical and population-based studies was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement to clarify whether Metabolic Syndrome (MetS) is a risk or a protective factor for incident dementia, Alzheimer disease (AD), and vascular dementia (VaD), and whether it's involved in progression to dementia in patients affected by mild cognitive impairment (MCI).MethodsSearch terms included (“metabolic syndrome” OR “syndrome x” OR “plurimetabolic syndrome”) AND (“dementia” OR “Alzheimer disease” OR “vascular dementia” OR “mild cognitive impairment” OR “MCI”). Research was restricted to articles published in English between January 1, 2000 and August 31, 2018. No age limit was set.ResultsAt the end of the selection procedure, nine longitudinal studies were selected for the meta-analysis: six studies enrolled cognitively well-functioning participants and three studies involved MCI patients. A total of 18,313 participants aged older than 40 years with mean MetS prevalence of 22.7% were followed on average for 9.41years. A fixed model was used to estimate pooled hazard ratios and 95% confidence intervals.ConclusionNo statistically significant pooled association emerged between MetS and incident dementia and AD. MetS increased the incidence of pure VaD. MetS increased the risk of progression from MCI to dementia. Follow-up length might be a key factor in investigating these associations further. Because MetS is constituted by a set of potentially modifiable factors, further studies with longer follow-up and repeated assessment of both MetS and cognitive status are desirable to draw definite conclusions.     

Cognitive Deficits in Older Adults With Psychotic Depression: A Meta-Analysis

A major depressive disorder with psychotic features, that is, psychotic depression (PD), is often accompanied by cognitive deficits, particularly in older patients. We aimed to assess to what extent various cognitive domains are affected in older patients with PD compared to those with nonpsychotic depression (NPD). Therefore, a systematic search was conducted in Medline, Embase, Web of Science, the Cumulative Index to Nursing and Allied Literature (CINAHL), Google Scholar, and Cochrane for all relevant studies. Hereafter, we conducted a meta-analysis of seven studies on cognitive deficits in older adults (55+ years), comparing patients with PD and patients with NPD. Compared to patients with NPD, those with PD not only showed a significantly poorer performance on overall cognitive function, with a Hedges’ g effect size of ?0.34 (95% confidence interval: ?0.56; ?0.12; p = 0.003), but also on nearly all separate cognitive domains, with Hedges’ g effect sizes ranging from ?0.26 to ?0.64 (all p's <0.003), of which attention was most adversely affected. Verbal fluency showed no significant effect, although this analysis may have been underpowered. The funnel plot suggested no significant publication bias (Egger test intercept: ?2.47; 95% confidence interval: ?5.50; 0.55; p = 0.09). We conclude that older patients with PD show more cognitive deficits on all cognitive domains, except for verbal fluency, compared to patients with NPD. It is crucial that clinicians and researchers take cognitive deficits into consideration in older adults with PD.     

Mild Cognitive Impairment and Caregiver Burden: A 3-Year-Longitudinal Study

ObjectivesMild cognitive impairment (MCI) is common, affecting 10%–35% of people over 65, and poses unique challenges for patients and their caregivers. Comparatively little research has examined caregiver burden in this population, with longitudinal research, in particular, lacking. We examined caregiver burden in a sample of people with MCI over 3 years.DesignThree-year observational study.SettingNine memory clinics in Australia.ParticipantsOne-hundred-and-eighty-five people with MCI and their caregivers.MeasurementsMeasures of caregiver burden, cognition, function, neuropsychiatric symptoms, driving status, and medication use were completed with patients and their caregivers at regular intervals over a 3-year period.ResultsBetween 21.1% and 29.5% of caregivers reported a clinically significant level of burden over the study. Patients’ higher levels of neuropsychiatric symptoms, lower functional ability, and lack of driving ability, and caregivers’ employment were associated with greater caregiver burden over time. Caregiver burden did not increase over time when controlling for patient and caregiver characteristics.ConclusionsHigh levels of caregiver burden are present in a significant proportion of caregivers of people with MCI. Clinical characteristics of patients – including severity of neuropsychiatric symptoms and functional impairment – and the employment status of caregivers predict burden. Such characteristics may help identify caregivers at greater risk of burden to target for intervention.     

The Construction and Evaluation of Executive Attention Training to Improve Selective Attention,Focused Attention,and Divided Attention for Older Adults With Mild Cognitive Impairment: A Randomized Controlled Trial

ObjectivesTo examine the immediate and long-term effects of executive attention training on selective attention, focused attention, and divided attention in older adults with mild cognitive impairment.MethodsA double-blind, multisite randomized controlled trial at five sites. Seventy participants (mean age: 78.19 ± 7.22 years) were assigned to an experimental group (executive attention training, n = 35) or an active control group (n = 35). The training duration was the same for both groups (45 minutes per session, 3 times per week, 18 sessions in total). Primary outcome measure was selective attention (Digit Span Task). Secondary outcome measures included focused attention (Stroop Color Word Test) and divided attention (Trail-Making Test Part B). Data were collected at pretest, post-test, 3-month follow-up, and 6-month follow-up.ResultsIn GEE analysis, findings indicated a significant improvement in selective attention at post-test, whereas divided attention showed significant reducing omission error at 3-month follow-up. There was no significant effect of group in focused attention associated with the executive attention training compared with active control group.ConclusionThe executive attention training significantly improved selective attention and divided attention performance. Future studies should identify transfer effects of attention training, and that can employ early screening to provide integrated attention training, and decrease its relevant risks on competency in performing daily activities, such as falling and driving.     

Depression Agency-Based Collaborative: Effect of Problem-Solving Therapy on Risk of Common Mental Disorders in Older Adults With Home Care Needs

BackgroundInterventions to prevent depression in older adults have mainly focused on young-old ambulatory adults, not on the old-old with disabilities who receive supportive services in their homes.ObjectiveThe Depression Agency-Based Collaborative (Dep-ABC) is a single-blind pilot randomized controlled trial assessing the effect of an intervention-development strategy using problem-solving therapy (PST) on the risk of common mental health disorders in this vulnerable population.MethodsThe intervention involved six to eight sessions of PST over 12 weeks. Participants were followed up to 12 months postintervention.ResultsDep-ABC randomized 104 participants—68.4% of eligible and 17.5% of all older adults screened. The proportion of participants with incident major depressive disorder or generalized anxiety disorder was 11.4% in PST and 14.3% in the enhanced usual care control arm. A test of the interaction between time and intervention for anxiety symptoms favored the PST arm (p = 0.04).ConclusionPST did not lower the risk of incident common mental illness but did lower anxiety symptom burden. Apart from low power, the effects of PST may have been blunted by referral for medical and aging services in the enhanced usual care group.     

Risk Aversion and Alzheimer Disease in Old Age

Objective: To test the hypothesis that late-life risk aversion is partly a prodromal sign of dementia. Methods: The authors’ design was a longitudinal clinical-pathologic cohort study. The setting included participants’ residences in the Chicago area, and a total of 874 older persons without dementia were enrolled. At baseline, risk aversion was assessed with questions involving choices between certain smaller rewards and uncertain larger rewards. At annual intervals thereafter, participants underwent evaluations that included cognitive testing and diagnosis of mild cognitive impairment (MCI) and dementia. At death, a neuropathologic examination was done to quantify common pathologies linked to dementia. Results: Risk aversion at study onset ranged from 0.05–0.91 (mean: 0.32, standard deviation: 0.31). During a mean of 4.6 years of follow-up, 123 (of 874) developed dementia. Higher risk aversion was associated with higher dementia incidence (hazard ratio [HR]: 2.08; 95% confidence interval: 1.18, 3.65) and more rapid decline in episodic (estimate: –0.062; standard error [SE]: 0.019; t [3677]: –3.33; p < 0.001) and semantic (estimate: –0.039; SE: 0.015; t [3655]: –2.61; p = 0.009) memory but not in other cognitive systems. Of 702 people without cognitive impairment at baseline, 223 developed incident MCI. Higher risk aversion was associated with higher incidence of MCI (HR: 2.10; 95% confidence interval: 1.34, 3.29) and more rapid episodic memory decline. In 181 neuropathologically examined individuals, higher risk aversion was associated with higher levels of plaques, tangles, and cerebral amyloid angiopathy. Conclusion: The results support the hypothesis that high risk aversion in old age is partly an early sign of the pathology of Alzheimer disease.     

The Effect of Cognitive Training in Patients with Mild Cognitive Impairment and Early Alzheimer's Disease: A Preliminary Study

Background and Purpose

The objective of this study was to determine the benefits of cognitive training in patients with amnestic mild cognitive impairment (aMCI) and those with early Alzheimer''s disease (AD).

Methods

Eleven patients with aMCI and nine with early AD (stage 4 on the Global Deterioration Scale) participated in this study. Six participants with aMCI and six with AD were allocated to the cognitive training group, while five participants with aMCI and three with AD were allocated to a wait-list control group. Multicomponent cognitive training was administered in 18 weekly, individual sessions. Outcome measures were undertaken at baseline, and at 2 weeks and 3 months of follow-up.

Results

In the trained MCI group, there were significant improvements in the delayed-recall scores on the Seoul Verbal Learning Test at both the 2-week and 3-month follow-ups compared with baseline (baseline, 1.6±1.5; 2 weeks, 4.4±1.5, p=0.04; 3 months, 4.6±2.3, p=0.04). The phonemic fluency scores (1.0±0.8 vs. 5.0±1.8, p=0.07) and Korean Mini-Mental State Examination scores (18.8±0.5 vs. 23.8±2.2, p=0.07) also showed a tendency toward improvement at the 2-week follow-up compared to baseline in the trained AD group.

Conclusions

This study provides evidence of the effectiveness of cognitive training in aMCI and early AD. The efficacy of cognitive training programs remains to be verified in studies with larger samples and a randomized design.     

The Utility of Episodic Memory Cut-Off Scores for Inclusion in Clinical Trials for Early Symptomatic Alzheimer Disease

Correctly diagnosing early symptomatic Alzheimer disease in the context of multinational clinical trials poses a significant challenge. Subjective complaints of memory are fairly ubiquitous in an older population, and establishing the presence of definitive cognitive decline from clinical assessments is difficult. Most such trials have adopted the use of standardized episodic memory measures as an inclusion criterion, typically setting the cutoff at one standard deviation below age normal means. This is useful in terms of establishing the presence of an objective impairment of memory, thereby excluding subjects with purely subjective complaints and increasing the probability that clinical outcome measures will be sensitive to disease progression. Further demographic adjustments are unnecessary as other demographic variables are not strongly associated with memory performance, are difficult to equate across cultures, and will not eventuate in reduced screen fail rates and would be challenging to implement. Not all episodic memory measures are equivalent for this purpose, however, and existing data suggest significant variability in terms of specificity for identifying true (i.e., amyloid positive) early symptomatic AD.