scholarly journals Dietary Factors and Neurodegenerative Disorders: An Umbrella Review of Meta-Analyses of Prospective Studies

2020 ◽  
Vol 11 (5) ◽  
pp. 1161-1173
Author(s):  
Janett Barbaresko ◽  
Arno Werner Lellmann ◽  
Annemarie Schmidt ◽  
Andreas Lehmann ◽  
Anna Maria Amini ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Parkinson Disease ◽  
Prospective Studies ◽  
Neurodegenerative Disorders ◽  
Risk Of Bias ◽  
Dietary Factors ◽  
Umbrella Review ◽  
Quality Of Evidence ◽  
Meta Analyses

ABSTRACT Diet has been hypothesized to be associated with neurodegenerative disorders. The aim was to conduct an umbrella review to summarize and evaluate the current evidence of prospective associations between any dietary factors and the incidence of neurodegenerative disorders. We conducted a systematic search in PubMed, Embase, and the Cochrane library up to November 2019 to identify systematic reviews with meta-analyses of prospective studies investigating the association between dietary factors (dietary patterns, foods and beverages, nutrients, and phytochemicals) and neurodegenerative disorders (cognitive decline, cognitive impairment, Alzheimer disease, all-cause dementia, and Parkinson disease). Summary risk ratios (SRRs) and 95% CIs were recalculated using a random effects model. We evaluated the risk of bias of identified meta-analyses and the quality of evidence for all associations. In total, 20 meta-analyses including 98 SRRs were identified. All original meta-analyses were rated as being at high risk of bias. Methodological concerns related mainly to the inappropriate synthesis, assessment, and discussion of the risk of bias of primary studies. For the recalculated meta-analyses, quality of evidence was moderate for inverse associations between higher adherence to the Mediterranean diet (SRR: 0.63; 95% CI: 0.48, 0.82; n = 4 primary studies) and higher fish intake (SRR: 0.72; 95% CI: 0.59, 0.89; n = 6) and Alzheimer disease, as well as for tea consumption and all-cause dementia (SRR: 0.74; 95% CI: 0.63, 0.88; n = 2) and Parkinson disease (SRR per 2 cups/d: 0.69; 95% CI: 0.54, 0.87; n = 5). This umbrella review provides a comprehensive overview of the available evidence on dietary factors and neurodegenerative disorders. The results indicate that the Mediterranean diet, fish, and tea could be inversely associated with neurodegenerative disorders. However, the quality of evidence was generally low, suggesting that further studies are likely to change the overall estimates. Thus, more well-conducted research, also investigating other dietary factors in association with neurodegenerative disorders, is warranted.

scholarly journals Role of dietary factors in the prevention and treatment for depression: an umbrella review of meta-analyses of prospective studies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yujie Xu ◽  
Linan Zeng ◽  
Kun Zou ◽  
Shufang Shan ◽  
Xiaoyu Wang ◽  
...  
Keyword(s):  
Prospective Studies ◽  
Dietary Factors ◽  
Current Evidence ◽  
Cochrane Library ◽  
Umbrella Review ◽  
Quality Of Evidence ◽  
Prevention And Treatment ◽  
Meta Analyses

AbstractThe role of diet in depression is becoming increasingly acknowledged. This umbrella review aimed to summarize comprehensively the current evidence reporting the effects of dietary factors on the prevention and treatment of depression. PubMed, Embase, and the Cochrane Library were searched up to June 2021 to identify relevant meta-analyses of prospective studies. Twenty-eight meta-analyses, with 40 summary estimates on dietary patterns (n = 8), food and beverages (n = 19), and nutrients (n = 13) were eligible. The methodological quality of most meta-analyses was low (50.0%) or very low (25.0%). Quality of evidence was moderate for inverse associations for depression incidence with healthy diet [risk ratio (RR): 0.74, 95% confidential interval (CI), 0.48–0.99, I2 = 89.8%], fish (RR: 0.88, 95% CI, 0.79–0.97, I2 = 0.0%), coffee (RR: 0.89, 95% CI, 0.84–0.94, I2 = 32.9%), dietary zinc (RR: 0.66, 95% CI 0.50–0.82, I2 = 13.9%), light to moderate alcohol (<40 g/day, RR: 0.77, 95% CI, 0.74–0.83, I2 = 20.5%), as well as for positive association with sugar-sweetened beverages (RR: 1.05, 95% CI, 1.01–1.09, I2 = 0.0%). For depression treatment, moderate-quality evidence was identified for the effects of probiotic [standardized mean difference (SMD): −0.31, 95% CI, −0.56 to −0.07, I2 = 48.2%], omega-3 polyunsaturated fatty acid (SMD: −0.28, 95% CI, −0.47 to −0.09, I2 = 75.0%) and acetyl-l-carnitine (SMD: −1.10, 95% CI, −1.65 to −0.56, I2 = 86.0%) supplementations. Overall, the associations between dietary factors and depression had been extensively evaluated, but none of them were rated as high quality of evidence, suggesting further studies are likely to change the summary estimates. Thus, more well-designed research investigating more detailed dietary factors in association with depression is warranted.

scholarly journals Virtual Reality in Neurorehabilitation: An Umbrella Review of Meta-Analyses

2021 ◽  
Vol 10 (7) ◽  
pp. 1478
Author(s):  
Alexandra Voinescu ◽  
Jie Sui ◽  
Danaë Stanton Fraser
Keyword(s):  
Virtual Reality ◽  
Cerebral Palsy ◽  
Brain Injury ◽  
Upper Limb ◽  
Umbrella Review ◽  
High Quality ◽  
Quality Of Evidence ◽  
Upper Limb Function ◽  
Meta Analyses

Neurological disorders are a leading cause of death and disability worldwide. Can virtual reality (VR) based intervention, a novel technology-driven change of paradigm in rehabilitation, reduce impairments, activity limitations, and participation restrictions? This question is directly addressed here for the first time using an umbrella review that assessed the effectiveness and quality of evidence of VR interventions in the physical and cognitive rehabilitation of patients with stroke, traumatic brain injury and cerebral palsy, identified factors that can enhance rehabilitation outcomes and addressed safety concerns. Forty-one meta-analyses were included. The data synthesis found mostly low- or very low-quality evidence that supports the effectiveness of VR interventions. Only a limited number of comparisons were rated as having moderate and high quality of evidence, but overall, results highlight potential benefits of VR for improving the ambulation function of children with cerebral palsy, mobility, balance, upper limb function, and body structure/function and activity of people with stroke, and upper limb function of people with acquired brain injury. Customization of VR systems is one important factor linked with improved outcomes. Most studies do not address safety concerns, as only nine reviews reported adverse effects. The results provide critical recommendations for the design and implementation of future VR programs, trials and systematic reviews, including the need for high quality randomized controlled trials to test principles and mechanisms, in primary studies and in meta-analyses, in order to formulate evidence-based guidelines for designing VR-based rehabilitation interventions.

scholarly journals Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses

2019 ◽  
Vol 54 (11) ◽  
pp. 681-688 ◽  
Author(s):  
Jozo Grgic ◽  
Ivana Grgic ◽  
Craig Pickering ◽  
Brad J Schoenfeld ◽  
David J Bishop ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Systematic Reviews ◽  
Exercise Performance ◽  
Methodological Quality ◽  
Muscle Endurance ◽  
Umbrella Review ◽  
Caffeine Ingestion ◽  
Quality Of Evidence ◽  
Meta Analyses

ObjectiveTo systematically review, summarise and appraise findings of published meta-analyses that examined the effects of caffeine on exercise performance.DesignUmbrella review.Data sourcesTwelve databases.Eligibility criteria for selecting studiesMeta-analyses that examined the effects of caffeine ingestion on exercise performance.ResultsEleven reviews (with a total of 21 meta-analyses) were included, all being of moderate or high methodological quality (assessed using the Assessing the Methodological Quality of Systematic Reviews 2 checklist). In the meta-analyses, caffeine was ergogenic for aerobic endurance, muscle strength, muscle endurance, power, jumping performance and exercise speed. However, not all analyses provided a definite direction for the effect of caffeine when considering the 95% prediction interval. Using the Grading of Recommendations Assessment, Development and Evaluation criteria the quality of evidence was generally categorised as moderate (with some low to very low quality of evidence). Most individual studies included in the published meta-analyses were conducted among young men.Summary/conclusionSynthesis of the currently available meta-analyses suggest that caffeine ingestion improves exercise performance in a broad range of exercise tasks. Ergogenic effects of caffeine on muscle endurance, muscle strength, anaerobic power and aerobic endurance were substantiated by moderate quality of evidence coming from moderate-to-high quality systematic reviews. For other outcomes, we found moderate quality reviews that presented evidence of very low or low quality. It seems that the magnitude of the effect of caffeine is generally greater for aerobic as compared with anaerobic exercise. More primary studies should be conducted among women, middle-aged and older adults to improve the generalisability of these findings.

scholarly journals Evidence-based umbrella review of cognitive effects of prefrontal tDCS

2020 ◽  
Author(s):  
Luis C Farhat ◽  
Andre F Carvalho ◽  
Marco Solmi ◽  
Andre R Brunoni
Keyword(s):  
Systematic Reviews ◽  
Meta Analysis ◽  
Measurement Tool ◽  
Affective Neuroscience ◽  
Umbrella Review ◽  
Quality Of Evidence ◽  
Neuroscience Research ◽  
Cochrane Database ◽  
Meta Analyses

Abstract Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique, which has been increasingly used as an investigational tool in neuroscience. In social and affective neuroscience research, the prefrontal cortex has been primarily targeted, since this brain region is critically involved in complex psychobiological processes subserving both ‘hot’ and ‘cold’ domains. Although several studies have suggested that prefrontal tDCS can enhance neuropsychological outcomes, meta-analyses have reported conflicting results. Therefore, we aimed to assess the available evidence by performing an umbrella review of meta-analyses. We evaluated the effects of prefrontal active vs sham tDCS on different domains of cognition among healthy and neuropsychiatric individuals. A MeaSurement Tool to Assess Systematic Reviews 2 was employed to evaluate the quality of meta-analyses, and the GRADE system was employed to grade the quality of evidence of every comparison from each meta-analysis. PubMed/MEDLINE, PsycINFO and the Cochrane Database of Systematic Reviews were searched, and 11 meta-analyses were included resulting in 55 comparisons. Only 16 comparisons reported significant effects favoring tDCS, but 13 of them had either very low or low quality of evidence. Of the remaining 39 comparisons which reported non-significant effects, 38 had either very low or low quality of evidence. Meta-analyses were rated as having critically low and low quality. Among several reasons to explain these findings, the lack of consensus and reproducibility in tDCS research is discussed.

scholarly journals Effects of Vitamin D Supplementation on Lipid Profile in Adults with the Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3352 ◽  
Author(s):  
Fatme AlAnouti ◽  
Myriam Abboud ◽  
Dimitrios Papandreou ◽  
Nadine Mahboub ◽  
Suzan Haidar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Blood Lipids ◽  
Low Dose ◽  
Vitamin D Supplementation ◽  
Risk Of Bias ◽  
Sensitivity Analyses ◽  
Quality Of Evidence ◽  
Randomized Controlled ◽  
Meta Analyses

Background: Metabolic syndrome (MetS) increases the risk of cardiovascular disease, with atherogenic dyslipidemia being a major contributing factor. Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to assess whether vitamin D supplementation (VDS) alleviates dyslipidemia in adults with MetS. Scientific databases (PUBMED, MEDLINE, CINAHL, EMBASE, Cochrane Library, ClinicalTrials.gov, International Clinical Trials Registry Platform) and the gray literature were searched for randomized controlled trials of VDS, reporting on blood lipids. A narrative review, meta-analyses, sensitivity analyses, and appraisal of the risk of bias and overall quality of evidence produced were conducted. Results: Seven studies were included, and four were meta-analyzed. The risk of bias was generally low, and the final quality of evidence was low or very low. VDS, whether in high or low dose, significantly increased endline vitamin D blood levels; did not affect total, low-density, high-density cholesterol levels, and novel lipid-related biomarkers; yet, significantly increased triglycerides (TG) levels compared with placebo (MD: 30.67 (95%CI: 4.89–56.45) mg/dL; p = 0.02 for low-dose VDS; and MD: 27.33 (95%CI: 2.06–52.59) mg/dL; p = 0.03 for high-dose VDS). Pertaining heterogeneity was high (I2 = 86%; and I2 = 51%, respectively), and some included studies had significantly higher baseline TG in the intervention arm. The sensitivity analyses revealed robust results. Conclusion: VDS seems not to affect blood lipids in adults with MetS.

scholarly journals Neurological Outcome Following Newborn Encephalopathy With and Without Perinatal Infection: A Systematic Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Mads Andersen ◽  
Mette Vestergård Pedersen ◽  
Ted Carl Kejlberg Andelius ◽  
Kasper Jacobsen Kyng ◽  
Tine Brink Henriksen
Keyword(s):  
Systematic Review ◽  
Neurological Outcome ◽  
Risk Of Bias ◽  
Perinatal Infection ◽  
Quality Of Evidence ◽  
Assessment Development ◽  
Cochrane Database ◽  
Newcastle Ottawa Scale ◽  
Meta Analyses

Background: Studies have suggested that neurological outcome may differ in newborns with encephalopathy with and without perinatal infection. We aimed to systematically review this association.Methods: We conducted this systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies were obtained from four databases including Pubmed, Embase, Web of Science, and The Cochrane Database. Newborns with encephalopathy with and without markers of perinatal infection were compared with regard to neurodevelopmental assessments, neurological disorders, and early biomarkers of brain damage. Risk of bias and quality of evidence were assessed by the Newcastle-Ottawa scale and Grading of Recommendations Assessment, Development and Evaluation (GRADE).Results: We screened 4,284 studies of which eight cohort studies and one case-control study met inclusion criteria. A narrative synthesis was composed due to heterogeneity between studies. Six studies were classified as having low risk of bias, while three studies were classified as having high risk of bias. Across all outcomes, the quality of evidence was very low. The neurological outcome was similar in newborns with encephalopathy with and without markers of perinatal infection.Conclusions: Further studies of higher quality are needed to clarify whether perinatal infection may affect neurological outcome following newborn encephalopathy.Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier CRD42020185717.

scholarly journals An umbrella review of systematic reviews and meta-analyses of observational investigations of obstructive sleep apnea and health outcomes

2021 ◽  
Author(s):  
Weiwei Chen ◽  
Yuting Li ◽  
Liliangzi Guo ◽  
Chenxing Zhang ◽  
Shaohui Tang
Keyword(s):  
Obstructive Sleep Apnea ◽  
Health Outcomes ◽  
Systematic Reviews ◽  
Coronary Revascularization ◽  
Umbrella Review ◽  
High Quality ◽  
Quality Of Evidence ◽  
Obstructive Sleep ◽  
Meta Analyses

Abstract Purpose The previous analysis of systematic reviews and meta-analyses have illustrated that obstructive sleep apnea (OSA) is correlated with multiple health outcomes. In the present research, our main aim was to execute an umbrella review to assess the available evidence for the associations between OSA and health outcomes. Methods Herein, a meta-analysis of previous observational investigations that have reported associations between OSA and health outcomes in all human populations and settings was performed. We used these studies to execute an umbrella review of available meta-analyses and systematic reviews. Results Sixty-six articles comprising 136 unique outcomes were enrolled in this analysis. Of the 136 unique outcomes, 111 unique outcomes had significant associations (p < 0.05). Only 7 outcomes (coronary revascularization after PCI, postoperative respiratory failure, steatosis, alaninetrans aminase (ALT) elevation, metabolic syndrome (MS), psoriasis, and Parkinson’s disease) had a high quality of evidence. Twenty-four outcomes had a moderate quality of evidence, and the remaining 80 outcomes had a weak quality of evidence. Sixty-nine outcomes exhibited significant heterogeneity. Twenty-five outcomes exhibited publication bias. Sixty-three (95%) studies showed critically low methodological quality. Conclusion Among the 66 meta-analyses exploring 136 unique outcomes, only 7 statistically significant outcomes were rated as high quality of evidence. OSA may correlate with an increased risk of coronary revascularization after PCI, postoperative respiratory failure, steatosis, ALT elevation, MS, psoriasis, and Parkinson’s disease.

scholarly journals Role of diet in type 2 diabetes incidence: umbrella review of meta-analyses of prospective observational studies

BMJ ◽  
2019 ◽  
pp. l2368 ◽  
Author(s):  
Manuela Neuenschwander ◽  
Aurélie Ballon ◽  
Katharina S Weber ◽  
Teresa Norat ◽  
Dagfinn Aune ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Dietary Factors ◽  
Alcoholic Beverages ◽  
Diabetes Incidence ◽  
Food Groups ◽  
Quality Of Evidence ◽  
Dietary Behaviours ◽  
Meta Analyses

Abstract Objective To summarise the evidence of associations between dietary factors and incidence of type 2 diabetes and to evaluate the strength and validity of these associations. Design Umbrella review of systematic reviews with meta-analyses of prospective observational studies. Data sources PubMed, Web of Science, and Embase, searched up to August 2018. Eligibility criteria Systematic reviews with meta-analyses reporting summary risk estimates for the associations between incidence of type 2 diabetes and dietary behaviours or diet quality indices, food groups, foods, beverages, alcoholic beverages, macronutrients, and micronutrients. Results 53 publications were included, with 153 adjusted summary hazard ratios on dietary behaviours or diet quality indices (n=12), food groups and foods (n=56), beverages (n=10), alcoholic beverages (n=12), macronutrients (n=32), and micronutrients (n=31), regarding incidence of type 2 diabetes. Methodological quality was high for 75% (n=115) of meta-analyses, moderate for 23% (n=35), and low for 2% (n=3). Quality of evidence was rated high for an inverse association for type 2 diabetes incidence with increased intake of whole grains (for an increment of 30 g/day, adjusted summary hazard ratio 0.87 (95% confidence interval 0.82 to 0.93)) and cereal fibre (for an increment of 10 g/day, 0.75 (0.65 to 0.86)), as well as for moderate intake of total alcohol (for an intake of 12-24 g/day v no consumption, 0.75 (0.67 to 0.83)). Quality of evidence was also high for the association for increased incidence of type 2 diabetes with higher intake of red meat (for an increment of 100 g/day, 1.17 (1.08 to 1.26)), processed meat (for an increment of 50 g/day, 1.37 (1.22 to 1.54)), bacon (per two slices/day, 2.07 (1.40 to 3.05)), and sugar sweetened beverages (for an increase of one serving/day, 1.26 (1.11 to 1.43)). Conclusions Overall, the association between dietary factors and type 2 diabetes has been extensively studied, but few of the associations were graded as high quality of evidence. Further factors are likely to be important in type 2 diabetes prevention; thus, more well conducted research, with more detailed assessment of diet, is needed. Systematic review registration PROSPERO CRD42018088106.

scholarly journals Differentiating PSP from MSA using MR planimetric measurements: a systematic review and meta-analysis

2021 ◽  
Author(s):  
Beatrice Heim ◽  
Florian Krismer ◽  
Klaus Seppi
Keyword(s):  
Sensitivity And Specificity ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Index Test ◽  
Study Quality ◽  
Parkinsonian Syndromes ◽  
Quantitative Mr ◽  
Meta Analyses ◽  
Planimetric Measurements

AbstractDifferential diagnosis of parkinsonian syndromes is considered one of the most challenging in neurology. Quantitative MR planimetric measurements were reported to discriminate between progressive supranuclear palsy (PSP) and non-PSP-parkinsonism. Several studies have used midbrain to pons ratio (M/P) and the Magnetic Resonance Parkinsonism Index (MRPI) in distinguishing PSP patients from those with Parkinson's disease. The current meta-analysis aimed to compare the performance of these measures in discriminating PSP from multiple system atrophy (MSA). A systematic MEDLINE review identified 59 out of 2984 studies allowing a calculation of sensitivity and specificity using the MRPI or M/P. Meta-analyses of results were carried out using random effects modelling. To assess study quality and risk of bias, the QUADAS-2 tool was used. Eight studies were suitable for analysis. The meta‐analysis showed a pooled sensitivity and specificity for the MRPI of PSP versus MSA of 79.2% (95% CI 72.7–84.4%) and 91.2% (95% CI 79.5–96.5%), and 84.1% (95% CI 77.2–89.2%) and 89.2% (95% CI 81.8–93.8%), respectively, for the M/P. The QUADAS-2 toolbox revealed a high risk of bias regarding the methodological quality of patient selection and index test, as all patients were seen in a specialized outpatient department without avoiding case control design and no predefined threshold was given regarding MRPI or M/P cut-offs. Planimetric brainstem measurements, in special the MRPI and M/P, yield high diagnostic accuracy for the discrimination of PSP from MSA. However, there is an urgent need for well-designed, prospective validation studies to ameliorate the concerns regarding the risk of bias.

scholarly journals Predictability of rotational tooth movement with orthodontic aligners comparing software-based and achieved data: A systematic review and meta-analysis of observational studies

2021 ◽  
pp. 146531252110272
Author(s):  
Despina Koletsi ◽  
Anna Iliadi ◽  
Theodore Eliades
Keyword(s):  
Effect Size ◽  
Tooth Movement ◽  
Data Extraction ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Patient Treatment ◽  
Qualitative Synthesis ◽  
Meta Analyses ◽  
Enamel Reduction

Objective: To evaluate all available evidence on the prediction of rotational tooth movements with aligners. Data sources: Seven databases of published and unpublished literature were searched up to 4 August 2020 for eligible studies. Data selection: Studies were deemed eligible if they included evaluation of rotational tooth movement with any type of aligner, through the comparison of software-based and actually achieved data after patient treatment. Data extraction and data synthesis: Data extraction was done independently and in duplicate and risk of bias assessment was performed with the use of the QUADAS-2 tool. Random effects meta-analyses with effect sizes and their 95% confidence intervals (CIs) were performed and the quality of the evidence was assessed through GRADE. Results: Seven articles were included in the qualitative synthesis, of which three contributed to meta-analyses. Overall results revealed a non-accurate prediction of the outcome for the software-based data, irrespective of the use of attachments or interproximal enamel reduction (IPR). Maxillary canines demonstrated the lowest percentage accuracy for rotational tooth movement (three studies: effect size = 47.9%; 95% CI = 27.2–69.5; P < 0.001), although high levels of heterogeneity were identified (I2: 86.9%; P < 0.001). Contrary, mandibular incisors presented the highest percentage accuracy for predicted rotational movement (two studies: effect size = 70.7%; 95% CI = 58.9–82.5; P < 0.001; I2: 0.0%; P = 0.48). Risk of bias was unclear to low overall, while quality of the evidence ranged from low to moderate. Conclusion: Allowing for all identified caveats, prediction of rotational tooth movements with aligner treatment does not appear accurate, especially for canines. Careful selection of patients and malocclusions for aligner treatment decisions remain challenging.

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