-
1.
Association Between Blood Pressure Variability With Dementia and Cognitive Impairment: A Systematic Review and Meta-Analysis.
de Heus, RAA, Tzourio, C, Lee, EJL, Opozda, M, Vincent, AD, Anstey, KJ, Hofman, A, Kario, K, Lattanzi, S, Launer, LJ, et al
Hypertension (Dallas, Tex. : 1979). 2021;(5):1478-1489
-
-
Free full text
-
Abstract
[Figure: see text].
-
2.
Anticholinergic burden (prognostic factor) for prediction of dementia or cognitive decline in older adults with no known cognitive syndrome.
Taylor-Rowan, M, Edwards, S, Noel-Storr, AH, McCleery, J, Myint, PK, Soiza, R, Stewart, C, Loke, YK, Quinn, TJ
The Cochrane database of systematic reviews. 2021;(5):CD013540
-
-
Free full text
-
Abstract
BACKGROUND Medications with anticholinergic properties are commonly prescribed to older adults. The cumulative anticholinergic effect of all the medications a person takes is referred to as the 'anticholinergic burden' because of its potential to cause adverse effects. It is possible that high anticholinergic burden may be a risk factor for development of cognitive decline or dementia. There are various scales available to measure anticholinergic burden but agreement between them is often poor. OBJECTIVES To assess whether anticholinergic burden, as defined at the level of each individual scale, is a prognostic factor for future cognitive decline or dementia in cognitively unimpaired older adults. SEARCH METHODS We searched the following databases from inception to 24 March 2021: MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), CINAHL (EBSCOhost), and ISI Web of Science Core Collection (ISI Web of Science). SELECTION CRITERIA We included prospective and retrospective longitudinal cohort and case-control observational studies with a minimum of one year' follow-up that examined the association between an anticholinergic burden measurement scale and future cognitive decline or dementia in cognitively unimpaired older adults. DATA COLLECTION AND ANALYSIS Two review authors independently assessed studies for inclusion, and undertook data extraction, assessment of risk of bias, and GRADE assessment. We extracted odds ratios (OR) and hazard ratios, with 95% confidence intervals (CI), and linear data on the association between anticholinergic burden and cognitive decline or dementia. We intended to pool each metric separately; however, only OR-based data were suitable for pooling via a random-effects meta-analysis. We initially established adjusted and unadjusted pooled rates for each available anticholinergic scale; then, as an exploratory analysis, established pooled rates on the prespecified association across scales. We examined variability based on severity of anticholinergic burden. MAIN RESULTS We identified 25 studies that met our inclusion criteria (968,428 older adults). Twenty studies were conducted in the community care setting, two in primary care clinics, and three in secondary care settings. Eight studies (320,906 participants) provided suitable data for meta-analysis. The Anticholinergic Cognitive Burden scale (ACB scale) was the only scale with sufficient data for 'scale-based' meta-analysis. Unadjusted ORs suggested an increased risk for cognitive decline or dementia in older adults with an anticholinergic burden (OR 1.47, 95% CI 1.09 to 1.96) and adjusted ORs similarly suggested an increased risk for anticholinergic burden, defined according to the ACB scale (OR 2.63, 95% CI 1.09 to 6.29). Exploratory analysis combining adjusted ORs across available scales supported these results (OR 2.16, 95% CI 1.38 to 3.38), and there was evidence of variability in risk based on severity of anticholinergic burden (ACB scale 1: OR 2.18, 95% CI 1.11 to 4.29; ACB scale 2: OR 2.71, 95% CI 2.01 to 3.56; ACB scale 3: OR 3.27, 95% CI 1.41 to 7.61); however, overall GRADE evaluation of certainty of the evidence was low. AUTHORS' CONCLUSIONS There is low-certainty evidence that older adults without cognitive impairment who take medications with anticholinergic effects may be at increased risk of cognitive decline or dementia.
-
3.
Effectiveness of omega-3 fatty acid supplementation in patients with Alzheimer disease: A systematic review and meta-analysis.
Araya-Quintanilla, F, Gutiérrez-Espinoza, H, Sánchez-Montoya, U, Muñoz-Yañez, MJ, Baeza-Vergara, A, Petersen-Yanjarí, M, Fernández-Lecaros, L
Neurologia. 2020;(2):105-114
Abstract
INTRODUCTION Alzheimer disease (AD) is a neurodegenerative disease characterised by progressive dementia associated with global cognitive dysfunction. METHODS We conducted a systematic review and meta-analysis of clinical trials evaluating omega-3 supplementation in patients with AD. OBJECTIVE To determine if there is scientific evidence of the effectiveness of omega-3 supplementation in improving cognitive function in patients with AD. SEARCH STRATEGY We included only randomised controlled trials (RCTs) from the following databases: Medline, Cochrane Central, Cinahl, and LILACS. An electronic search was also conducted using Google Scholar. STUDY SELECTION Six articles met the eligibility criteria. The risk of bias was assessed following the Cochrane method. CONCLUSION There is no consistent evidence to support the effectiveness of omega-3 supplementation in improving cognitive function in AD patients in the short and medium term.
-
4.
Differential effects of cognitive training modules in healthy aging and mild cognitive impairment: A comprehensive meta-analysis of randomized controlled trials.
Basak, C, Qin, S, O'Connell, MA
Psychology and aging. 2020;(2):220-249
-
-
Free full text
-
Abstract
This meta-analysis was designed to compare the effectiveness of 2 cognitive training modules, single-component training, which targets 1 specific cognitive ability, versus multicomponent training, which trains multiple cognitive abilities, on both trained abilities (near transfer) and untrained abilities (far transfer) in older adults. The meta-analysis also assessed whether individual differences in mental status interacted with the extent of transfer. Eligible randomized controlled trials (215 training studies) examined the immediate effects of cognitive training in either healthy aging (HA) or mild cognitive impairment (MCI). Results yielded an overall net-gain effect size (g) for the cognitive training of 0.28 (p < .001). These effects were similar across mental status and training modules, and were significant for both near (g = 0.37) and far (g = 0.22) transfer. Although all training modules yielded significant near transfer, only a few yielded significant far transfer. Single-component training of executive functions was most effective on near and far transfer, with processing speed training improving everyday functioning. All modules of multicomponent training (specific and nonspecific) yielded significant near and far transfer, including everyday functioning. Training effects on cognition were moderated by educational attainment and number of cognitive outcomes, but only in HA. These findings suggest that, in older adults, all modules of multicomponent training are more effective in engendering near and far transfer, including everyday functioning, when compared with single-component training modules. (PsycINFO Database Record (c) 2020 APA, all rights reserved).
-
5.
Elevated serum TC and LDL-C levels in Alzheimer's disease and mild cognitive impairment: A meta-analysis study.
Liu, Y, Zhong, X, Shen, J, Jiao, L, Tong, J, Zhao, W, Du, K, Gong, S, Liu, M, Wei, M
Brain research. 2020;:146554
Abstract
Serum lipid levels such as triglyceride and cholesterol has been reported to play an important role in the pathophysiological process of Alzheimer disease (AD) and mild cognitive impairment (MCI). However, it still remains controversial in different studies. Here, we performed a meta-analysis to assess the importance of serum levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in AD and MCI patients. PubMed, China National Knowledge Infrastructure (CNKI) system database were used to identify 17 studies (10 AD-only + 4 MCI-only + 3 shared AD/MCI), including 2333 cases and 3615 healthy controls (HC). We found that compared with HC, both the serum TC levels [SMD = 0.58; 95%CI (0.25, 0.90); P = 0.001) and the serum LDL-C levels [SMD = 0.7780; 95%CI (0.3940, 1.1521); P = 0.000] were higher in cognitive impairment population (including AD and MCI) than those in HC, respectively. Furthermore, we analyzed the serum TC and LDL-C levels in AD and MCI patients. We found that the serum TC levels [SMD = 0.76; 95% CI (0.13, 1.40); P = 0.019]1 and the LDL-C levels [SMD = 1.40; 95% CI (0.70, 2.10; P = 0.000] were increased in AD patients. In the MCI patients, the serum TC levels [SMD = 0.30; 95%CI (0.01, 0.59); P = 0.041] had a significantly upward trend, while the LDL-C levels had no significant change, compared with HC subjects. However, there is no significant changes in HDL-C and TG levels in AD or MCI patients. Therefore, our results suggested that the elevated TC and LDL-C levels may be a potential risk factor for cognitive impairment.
-
6.
The use of commercial computerised cognitive games in older adults: a meta-analysis.
Bonnechère, B, Langley, C, Sahakian, BJ
Scientific reports. 2020;(1):15276
Abstract
Brain training programs are currently one effective solution to prevent cognitive decline in healthy aging. We conducted a meta-analysis of randomized controlled trials assessing the use of commercially available computerised cognitive games to improve cognitive function in people aged above 60 years old without cognitive impairment. 1,543 participants from sixteen studies were included in the meta-analysis. Statistically significant improvements were observed for processing speed (SMD increased 0.40 [95% CI 0.20-0.60], p < 0.001), working memory (0.21 [95% CI 0.08-0.34], p = 0.001), executive function (0.21 [95% CI 0.06-0.35], p = 0.006), and for verbal memory (0.12 [95% CI 0.01-0.24, p = 0.031), but not for attention or visuospatial abilities. No relationship between the age of the participants and the amount of training was found. Commercially available computerised cognitive games are effective in improving cognitive function in participants without cognitive impairment aged over 60 years.
-
7.
Computerised cognitive training for 12 or more weeks for maintaining cognitive function in cognitively healthy people in late life.
Gates, NJ, Rutjes, AW, Di Nisio, M, Karim, S, Chong, LY, March, E, Martínez, G, Vernooij, RW
The Cochrane database of systematic reviews. 2020;(2):CD012277
-
-
Free full text
-
Abstract
BACKGROUND Increasing age is associated with a natural decline in cognitive function and is the greatest risk factor for dementia. Cognitive decline and dementia are significant threats to independence and quality of life in older adults. Therefore, identifying interventions that help to maintain cognitive function in older adults or that reduce the risk of dementia is a research priority. Cognitive training uses repeated practice on standardised exercises targeting one or more cognitive domains and may be intended to improve or maintain optimal cognitive function. This review examines the effects of computerised cognitive training interventions lasting at least 12 weeks on the cognitive function of healthy adults aged 65 or older and has formed part of a wider project about modifying lifestyle to maintain cognitive function. We chose a minimum 12 weeks duration as a trade-off between adequate exposure to a sustainable intervention and feasibility in a trial setting. OBJECTIVES To evaluate the effects of computerised cognitive training interventions lasting at least 12 weeks on cognitive function in cognitively healthy people in late life. SEARCH METHODS We searched to 31 March 2018 in ALOIS (www.medicine.ox.ac.uk/alois), and we performed additional searches of MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov, and the WHO Portal/ICTRP (www.apps.who.int/trialsearch), to ensure that the search was as comprehensive and as up-to-date as possible to identify published, unpublished, and ongoing trials. SELECTION CRITERIA We included randomised controlled trials (RCTs) and quasi-RCTs, published or unpublished, reported in any language. Participants were cognitively healthy people, and at least 80% of the study population had to be aged 65 or older. Experimental interventions adhered to the following criteria: intervention was any form of interactive computerised cognitive intervention - including computer exercises, computer games, mobile devices, gaming console, and virtual reality - that involved repeated practice on standardised exercises of specified cognitive domain(s) for the purpose of enhancing cognitive function; the duration of the intervention was at least 12 weeks; cognitive outcomes were measured; and cognitive training interventions were compared with active or inactive control interventions. DATA COLLECTION AND ANALYSIS We performed preliminary screening of search results using a 'crowdsourcing' method to identify RCTs. At least two review authors working independently screened the remaining citations against inclusion criteria. At least two review authors also independently extracted data and assessed the risk of bias of included RCTs. Where appropriate, we synthesised data in random-effects meta-analyses, comparing computerised cognitive training (CCT) separately with active and inactive controls. We expressed treatment effects as standardised mean differences (SMDs) with 95% confidence intervals (CIs). We used GRADE methods to describe the overall quality of the evidence for each outcome. MAIN RESULTS We identified eight RCTs with a total of 1183 participants. The duration of the interventions ranged from 12 to 26 weeks; in five trials, the duration of intervention was 12 or 13 weeks. The included studies had moderate risk of bias, and the overall quality of evidence was low or very low for all outcomes. We compared CCT first against active control interventions, such as watching educational videos. Negative SMDs favour CCT over control. Trial results suggest slight improvement in global cognitive function at the end of the intervention period (12 weeks) (standardised mean difference (SMD) -0.31, 95% confidence interval (CI) -0.57 to -0.05; 232 participants; 2 studies; low-quality evidence). One of these trials also assessed global cognitive function 12 months after the end of the intervention; this trial provided no clear evidence of a persistent effect (SMD -0.21, 95% CI -0.66 to 0.24; 77 participants; 1 study; low-quality evidence). CCT may result in little or no difference at the end of the intervention period in episodic memory (12 to 17 weeks) (SMD 0.06, 95% CI -0.14 to 0.26; 439 participants; 4 studies; low-quality evidence) or working memory (12 to 16 weeks) (SMD -0.17, 95% CI -0.36 to 0.02; 392 participants; 3 studies; low-quality evidence). Because of the very low quality of the evidence, we are very uncertain about the effects of CCT on speed of processing and executive function. We also compared CCT to inactive control (no interventions). We found no data on our primary outcome of global cognitive function. At the end of the intervention, CCT may lead to slight improvement in episodic memory (6 months) (mean difference (MD) in Rivermead Behavioural Memory Test (RBMT) -0.90 points, 95% confidence interval (CI) -1.73 to -0.07; 150 participants; 1 study; low-quality evidence) but can have little or no effect on executive function (12 weeks to 6 months) (SMD -0.08, 95% CI -0.31 to 0.15; 292 participants; 2 studies; low-quality evidence), working memory (16 weeks) (MD -0.08, 95% CI -0.43 to 0.27; 60 participants; 1 study; low-quality evidence), or verbal fluency (6 months) (MD -0.11, 95% CI -1.58 to 1.36; 150 participants; 1 study; low-quality evidence). We could not determine any effects on speed of processing because the evidence was of very low quality. We found no evidence on quality of life, activities of daily living, or adverse effects in either comparison. AUTHORS' CONCLUSIONS We found low-quality evidence suggesting that immediately after completion of the intervention, small benefits of CCT may be seen for global cognitive function when compared with active controls, and for episodic memory when compared with an inactive control. These benefits are of uncertain clinical importance. We found no evidence that the effect on global cognitive function persisted 12 months later. Our confidence in the results was low, reflecting the overall quality of the evidence. In five of the eight trials, the duration of the intervention was just three months. The possibility that more extensive training could yield larger benefit remains to be more fully explored. We found substantial literature on cognitive training, and collating all available scientific information posed problems. Duration of treatment may not be the best way to categorise interventions for inclusion. As the primary interest of older people and of guideline writers and policymakers involves sustained cognitive benefit, an alternative would be to categorise by length of follow-up after selecting studies that assess longer-term effects.
-
8.
Chromosomal damage measured by the cytokinesis block micronucleus cytome assay in diabetes and obesity - A systematic review and meta-analysis.
Franzke, B, Schwingshackl, L, Wagner, KH
Mutation research. Reviews in mutation research. 2020;:108343
Abstract
The percentage of people affected by overweight, obesity and/or diabetes drastically increased within the last decades. This development is still ongoing, which puts a large part of our society at increased risk for diseases, such as cancer, cardiovascular diseases and cognitive impairment. Especially the development of type 2 diabetes and overweight/obesity could theoretically be prevented. The loss of DNA and genome stability is associated with the above-mentioned metabolic diseases. Insulin resistance, high blood glucose levels or increased body fat are linked to a chronically elevated inflammatory state. This amplifies oxidative stress, might lead to oxidative DNA damage, impairs the cellular proliferation process and results in mutations; all of which increase the possibility for the development of dysfunctional cells, tissue and organs. An established method to measure chromosomal damage is the cytokinesis block micronucleus (CBMN) cytome assay. The aim of this systematic review and meta-analysis is to collect and analyse the current literature of diabetic, obese and overweight patients and their link to cellular mutations measured by the CBMN assay. A clear trend towards increased genome damage in these metabolic diseases was observed. Significantly increased frequencies of chromosomal aberrations were seen in type 2 diabetic subjects (micronuclei frequency: SMD: 1.18, 95% CI: 0.76, 1.60; I2 = 84%). In both, type 1 and type 2 diabetics, disease progression as well as medical quality and quantity were linked to further elevated genome instability. In type 1 diabetic and overweight/obese subjects the number of studies is small and for valid and reliable results more data are needed. Besides the traditionally used material for this method, PBMCs, we extended our analysis to buccal cells in order to qualitatively compare the two cell types. Finally, we discuss knowledge as well as technical/methodical gaps of the CBMN cytome assay and its usability for clinical practice in these metabolic diseases.
-
9.
Risk Factors for Delirium and Cognitive Decline Following Coronary Artery Bypass Grafting Surgery: A Systematic Review and Meta-Analysis.
Greaves, D, Psaltis, PJ, Davis, DHJ, Ross, TJ, Ghezzi, ES, Lampit, A, Smith, AE, Keage, HAD
Journal of the American Heart Association. 2020;(22):e017275
Abstract
Background Coronary artery bypass grafting (CABG) is known to improve heart function and quality of life, while rates of surgery-related mortality are low. However, delirium and cognitive decline are common complications. We sought to identify preoperative, intraoperative, and postoperative risk or protective factors associated with delirium and cognitive decline (across time) in patients undergoing CABG. Methods and Results We conducted a systematic search of Medline, PsycINFO, EMBASE, and Cochrane (March 26, 2019) for peer-reviewed, English publications reporting post-CABG delirium or cognitive decline data, for at least one risk factor. Random-effects meta-analyses estimated pooled odds ratio for categorical data and mean difference or standardized mean difference for continuous data. Ninety-seven studies, comprising data from 60 479 patients who underwent CABG, were included. Moderate to large and statistically significant risk factors for delirium were as follows: (1) preoperative cognitive impairment, depression, stroke history, and higher European System for Cardiac Operative Risk Evaluation (EuroSCORE) score, (2) intraoperative increase in intubation time, and (3) postoperative presence of arrythmia and increased days in the intensive care unit; higher preoperative cognitive performance was protective for delirium. Moderate to large and statistically significant risk factors for acute cognitive decline were as follows: (1) preoperative depression and older age, (2) intraoperative increase in intubation time, and (3) postoperative presence of delirium and increased days in the intensive care unit. Presence of depression preoperatively was a moderate risk factor for midterm (1-6 months) post-CABG cognitive decline. Conclusions This meta-analysis identified several key risk factors for delirium and cognitive decline following CABG, most of which are nonmodifiable. Future research should target preoperative risk factors, such as depression or cognitive impairment, which are potentially modifiable. Registration URL: https://www.crd.york.ac.uk/prospero/; Unique identifier: CRD42020149276.
-
10.
Long-chain omega-3 polyunsaturated fatty acids and cognitive decline in non-demented adults: a systematic review and meta-analysis.
Alex, A, Abbott, KA, McEvoy, M, Schofield, PW, Garg, ML
Nutrition reviews. 2020;(7):563-578
Abstract
CONTEXT Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFAs) are widely considered as nootropic agents that may be beneficial in reversing cognitive impairment. OBJECTIVE The present systematic review of randomized controlled trials was conducted to determine the changes in cognitive function after intervention with LCn-3PUFA supplementation in non-demented adults, including those with mild cognitive impairment. DATA SOURCES Five databases (MEDLINE, CINAHL, Scopus, EMBASE, and the Cochrane Library) were searched systematically along with reference lists of selected articles. STUDY SELECTION Studies were eligible for inclusion if they measured the effect of LCn-3PUFA supplementation on cognition in non-demented adults. DATA EXTRACTION A total of 787 records were screened, of which 25 studies were eligible for inclusion. Treatment effects were summarized as global cognitive function for primary outcome and measured using the Mini-Mental State Examination and individual cognitive domains for secondary outcome. The pooled effect sizes were estimated using Hedge's g and random-effects modeling. DATA ANALYSIS Results from randomized controlled trials indicate that LCn-3PUFAs have no effect on global cognitive function (Hedge's g = 0.02; 95% confidence interval, -0.12 to 0.154), and among the specific cognitive domains, only memory function showed a mild benefit (Hedge's g = 0.31; P = 0.003; z = 2.945). CONCLUSION The existing literature suggests that LCn-3PUFA supplementation could provide a mild benefit in improving memory function in non-demented older adults. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. CRD42017078664.