The metabolic signature of cardiorespiratory fitness: a protocol for a systematic review and meta-analysis

IntroductionA low cardiorespiratory fitness (CRF) is a strong and independent predictor of cardiometabolic, cancer and all-cause mortality. To date, the mechanisms linking CRF with reduced mortality remain largely unknown. Metabolomics, which is a powerful metabolic phenotyping technology to unravel molecular mechanisms underlying complex phenotypes, could elucidate how CRF fosters human health.Methods and analysisThis study aims at systematically reviewing and meta-analysing the literature on metabolites of any human tissue sample, which are positively or negatively associated with CRF. Studies reporting estimated CRF will not be considered. No restrictions will be placed on the metabolomics technology used to measure metabolites. PubMed, Web of Science and EMBASE will be searched for relevant articles published until the date of the last search. Two authors will independently screen full texts of selected abstracts. References and citing articles of included articles will be screened for additional relevant publications. Data regarding study population, tissue samples, analytical technique, quality control, data processing, metabolites associated to CRF, cardiopulmonary exercise test protocol and exercise exhaustion criteria will be extracted. Methodological quality will be assessed using a modified version of QUADOMICS. Narrative synthesis as well as tabular/charted presentation of the extracted data will be included. If feasible, meta-analyses will be used to investigate the associations between identified metabolites and CRF. Potential sources of heterogeneity will be explored in meta-regressions.Ethics and disseminationNo ethics approval is required. The results will be published in a peer-reviewed journal and as conference presentation.PROSPERO registration numberCRD42020214375.

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What is a multiple treatments meta-analysis?

Epidemiology and Psychiatric Sciences ◽

10.1017/s2045796011000837 ◽

2012 ◽

Vol 21 (2) ◽

pp. 151-153 ◽

Cited By ~ 15

Author(s):

A. Cipriani ◽

C. Barbui ◽

C. Rizzo ◽

G. Salanti

Keyword(s):

Evidence Based Medicine ◽

Treatment Effects ◽

Meta Analysis ◽

Evidence Based ◽

Relative Efficacy ◽

Analytical Technique ◽

Multiple Treatments ◽

Meta Analyses ◽

Based Medicine ◽

Indirect Comparisons

Standard meta-analyses are an effective tool in evidence-based medicine, but one of their main drawbacks is that they can compare only two alternative treatments at a time. Moreover, if no trials exist which directly compare two interventions, it is not possible to estimate their relative efficacy. Multiple treatments meta-analyses use a meta-analytical technique that allows the incorporation of evidence from both direct and indirect comparisons from a network of trials of different interventions to estimate summary treatment effects as comprehensively and precisely as possible.

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Diagnostic Accuracy of the Xpert MTB/RIF Assay for Lymph Node Tuberculosis: A Systematic Review and Meta-Analysis

BioMed Research International ◽

10.1155/2019/4878240 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 3

Author(s):

Guocan Yu ◽

Fangming Zhong ◽

Bo Ye ◽

Xudong Xu ◽

Da Chen ◽

...

Keyword(s):

Lymph Node ◽

Sensitivity And Specificity ◽

Meta Analysis ◽

Needle Aspiration ◽

Diagnostic Efficiency ◽

Tissue Samples ◽

Significant Difference ◽

Lymph Node Tuberculosis ◽

Meta Analyses ◽

Composite Reference Standard

Objectives. To evaluate the performance of Xpert MTB/RIF for lymph node tuberculosis (LNTB). Methods. We searched databases for published reports. We reviewed the studies and identified the performance of Xpert MTB/RIF with respect to a composite reference standard (CRS) and culture. We used a bivariate random-effects model to perform meta-analyses and used metaregression to analyze sources of heterogeneity. Results. 15 independent studies compared Xpert MTB/RIF with CRS while 21 comparing it with culture were included. The pooled sensitivity and specificity of Xpert MTB/RIF were 79% and 98% compared to that of CRS, respectively, and 84% and 91% compared to that of culture, respectively. The pooled sensitivity and specificity using fine needle aspiration (FNA) samples versus CRS were 80% and 96%, whereas those against culture were 90% and 89%, respectively. The percentages while working with tissue samples versus CRS were 76% and 100%, respectively, whereas those against culture were 76% and 92%, respectively. There was no significant difference in diagnostic efficiency among the types of specimen. Conclusions. Xpert MTB/RIF demonstrates good diagnostic efficiency for LNTB and is not related to the type of specimen, obtained via different routes.

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Pain-related opioidergic and dopaminergic neurotransmission: Dual Meta-Analyses of PET Radioligand Studies

10.1101/2020.09.18.302943 ◽

2020 ◽

Author(s):

Sergio Guerra Garcia ◽

Andrea Spadoni ◽

Jennifer Mitchell ◽

Irina A. Strigo

Keyword(s):

Human Brain ◽

Molecular Mechanisms ◽

Meta Analysis ◽

Inferior Frontal Gyrus ◽

Superior Temporal Gyrus ◽

Cingulate Gyrus ◽

Positron Emission ◽

Pet Radiotracers ◽

Meta Analyses ◽

Coordinate Data

AbstractMolecular mechanisms of the interaction between pain and reward associated with pain relief processes in the human brain are still incompletely understood. This is partially due to the invasive nature of the available techniques to visualize and measure metabolic activity. Positron Emission Tomography (PET) radioligand studies using radioactive substances are still the only available modality to date that allows for the investigation of the molecular mechanisms in the human brain. For pain and reward studies, the most commonly studied PET radiotracers are [11C]-carfentanil (CFN) and [11C]- or [18F]-diprenorphine (DPN), which bind to opioid receptors, and [11C]-raclopride (RAC) and [18F]-fallypride (FAL) tracers, which bind to dopamine receptors. The current meta-analysis looks at 15 pain-related studies using opioid radioligands and 8 studies using dopamine radioligands in an effort to consolidate the available data into the most likely activated regions. Our primary goal was to identify regions of shared opioid/dopamine neurotransmission during pain-related experiences. SDM analysis of previously published voxel coordinate data showed that opioidergic activations were strongest in the bilateral caudate, thalamus, right putamen, cingulate gyrus, midbrain, inferior frontal gyrus, and left superior temporal gyrus. The dopaminergic studies showed that the bilateral caudate, thalamus, right putamen, cingulate gyrus, and left putamen had the highest activations. We were able to see a clear overlap between opioid and dopamine activations in a majority of the regions during pain-related processing, though there were some unique areas of dopaminergic activation such as the left putamen. Regions unique to opioidergic activation include the midbrain, inferior frontal gyrus, and left superior temporal gyrus. By investigating the regions of dopaminergic and opioidergic activation, we can potentially provide more targeted treatment to these sets of receptors in patients with pain conditions. These findings could eventually assist in the development of more targeted medication in order to help treat pain conditions and simultaneously prevent physical dependency.

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Pairwise genetic meta-analyses between schizophrenia and substance dependence phenotypes reveals novel association signals

10.1101/2021.09.12.21263471 ◽

2021 ◽

Author(s):

Laura A. Greco ◽

William R. Reay ◽

Christopher V. Dayas ◽

Murray J. Cairns

Keyword(s):

Substance Use ◽

Molecular Mechanisms ◽

Substance Dependence ◽

System Development ◽

Causal Effect ◽

Meta Analysis ◽

Nervous System Development ◽

Cannabis Use ◽

Individual Substance ◽

Meta Analyses

AbstractAlmost half of individuals diagnosed with schizophrenia also present with a substance use disorder, however, little is known about potential molecular mechanisms underlying this comorbidity. We used genetic analyses to enhance our understanding of the molecular overlap between these conditions. Our analyses revealed a positive genetic correlation between schizophrenia and the following dependence phenotypes: alcohol (rg = 0.3685, SE = 0.0768, P = 1.61 × 10−06), cannabis use disorder (rg = 0.309, SE = 0.0332, P = 1.19 × 10−20) and nicotine dependence (rg = 0.1177, SE = 0.0436, P = 7.0 × 10-03), as well as lifetime cannabis use (rg = 0.234, SE = 0.0298, P = 3.73 × 10−15) and drinks per week (rg = 0.0688, SE = 0.0217, P = 1.5 × 10−03). We further constructed latent causal variable (LCV) models to test for partial genetic causality and found evidence for a potential causal relationship between alcohol dependence and schizophrenia (GCP = 0.6, SE = 0.22, P = 1.6 × 10−03). This putative causal effect with schizophrenia was not seen using a continuous phenotype of drinks consumed per week, suggesting that distinct molecular mechanisms underlying dependence are involved in the relationship between alcohol and schizophrenia. To localise the specific genetic overlap between schizophrenia and substance use disorders, we conducted a gene-based and gene-set pairwise meta-analysis between schizophrenia and each of the four individual substance dependence phenotypes in up to 790,806 individuals. These bivariate meta-analyses identified 44 associations not observed in the individual GWAS, including five shared genes that play a key role in early central nervous system development. These genes may play an important role in substance dependence in schizophrenia, and, as a result, could represent important targets for future treatment or early intervention, as comorbid substance dependence is associated with poor treatment adherence, greater chronicity and increased mortality.

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Defence priming in Arabidopsis – a Meta-Analysis

Scientific Reports ◽

10.1038/s41598-019-49811-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 7

Author(s):

Sara M. Westman ◽

Karen J. Kloth ◽

Johannes Hanson ◽

Anna B. Ohlsson ◽

Benedicte R. Albrectsen

Keyword(s):

Biotic Stress ◽

Agricultural Production ◽

Molecular Mechanisms ◽

Meta Analysis ◽

Plant Defence ◽

Early Age ◽

Priming Effects ◽

Pests And Diseases ◽

Published Evidence ◽

Meta Analyses

Abstract Defence priming by organismal and non-organismal stimulants can reduce effects of biotic stress in plants. Thus, it could help efforts to enhance the sustainability of agricultural production by reducing use of agrochemicals in protection of crops from pests and diseases. We have explored effects of applying this approach to both Arabidopsis plants and seeds of various crops in meta-analyses. The results show that its effects on Arabidopsis plants depend on both the priming agent and antagonist. Fungi and vitamins can have strong priming effects, and priming is usually more effective against bacterial pathogens than against herbivores. Moreover, application of bio-stimulants (particularly vitamins and plant defence elicitors) to seeds can have promising defence priming effects. However, the published evidence is scattered, does not include Arabidopsis, and additional studies are required before we can draw general conclusions and understand the molecular mechanisms involved in priming of seeds’ defences. In conclusion, defence priming of plants has clear potential and application of bio-stimulants to seeds may protect plants from an early age, promises to be both labour- and resource-efficient, poses very little environmental risk, and is thus both economically and ecologically promising.

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Are the Current Cardiac Rehabilitation Programs Optimized to Improve Cardiorespiratory Fitness in Patients? A Meta-Analysis

Journal of Aging and Physical Activity ◽

10.1123/japa.2019-0363 ◽

2020 ◽

pp. 1-16

Author(s):

Agustín Manresa-Rocamora ◽

José Manuel Sarabia ◽

Julio Sánchez-Meca ◽

José Oliveira ◽

Francisco Jose Vera-Garcia ◽

...

Keyword(s):

Confidence Interval ◽

Cardiac Rehabilitation ◽

Cardiorespiratory Fitness ◽

Meta Analysis ◽

Statistical Significance ◽

Empirical Studies ◽

Mean Difference ◽

Continuous Training ◽

Rehabilitation Programs ◽

Meta Analyses

Previous meta-analyses have shown that high-intensity interval training (HIIT) is more suitable than moderate continuous training (MCT) for improving peak oxygen uptake (VO2peak) in patients with coronary artery disease. However, none of these meta-analyses have tried to explain the heterogeneity of the empirical studies in optimizing cardiac rehabilitation programs. Therefore, our aims were (a) to estimate the effect of MCT and HIIT on VO2peak, and (b) to find the potential moderator variables. A search was conducted in PubMed, Scopus, and ScienceDirect. Out of the 3,110 references retrieved, 29 studies fulfilled the selection criteria to be included in our meta-analysis. The mean difference was used as the effect size index. Our results showed significant enhancements in VO2peak after cardiac rehabilitation based on MCT and HIIT (mean difference = 3.23; 95% confidence interval [2.81, 3.65] ml·kg−1·min−1 and mean difference = 4.61; 95% confidence interval [4.02, 5.19] ml·kg−1·min−1, respectively), with greater increases after HIIT (p < .001). Heterogeneity analyses reached statistical significance with moderate heterogeneity for MCT (p < .001; I2 = 67.0%), whereas no heterogeneity was found for the effect of HIIT (p = .220; I2 = 22.0%). Subgroup analyses showed significant between-group heterogeneity of the MCT-induced effect based on the training mode (p < .001; I2 = 90.4%), the risk of a new event (p = .010; I2 = 77.4%), the type of cardiovascular event (p = .009; I2 = 84.8%), the wait time to start cardiac rehabilitation (p = .010; I2 = 76.6%), and participant allocation (p = .002; I2 = 89.9%). Meta-regressions revealed that the percentages of patients undergoing a revascularization procedure (B = −0.022; p = .041) and cardiorespiratory fitness at baseline (B = −0.103; p = .025) were inversely related to the MCT-induced effect on the VO2peak.

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Biomedical applications: Pitfalls in the practice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169626 ◽

1994 ◽

Vol 52 ◽

pp. 378-379

Author(s):

J. D. Shelburne ◽

Peter Ingram ◽

Victor L. Roggli ◽

Ann LeFurgey

Keyword(s):

Operating Room ◽

Liquid Nitrogen ◽

Lung Tissue ◽

Biomedical Applications ◽

Microprobe Analysis ◽

Tissue Sample ◽

Cellular Level ◽

Tissue Samples ◽

Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

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A Meta-Analysis of Interviews and Cognitive Ability

Journal of Personnel Psychology ◽

10.1027/1866-5888/a000091 ◽

2013 ◽

Vol 12 (4) ◽

pp. 157-169 ◽

Cited By ~ 7

Author(s):

Philip L. Roth ◽

Allen I. Huffcutt

Keyword(s):

Cognitive Ability ◽

Meta Analysis ◽

Incremental Validity ◽

Employment Interviews ◽

Moderator Analysis ◽

The Future ◽

Research Questions ◽

Meta Analyses ◽

The Relationship

The topic of what interviews measure has received a great deal of attention over the years. One line of research has investigated the relationship between interviews and the construct of cognitive ability. A previous meta-analysis reported an overall corrected correlation of .40 ( Huffcutt, Roth, & McDaniel, 1996 ). A more recent meta-analysis reported a noticeably lower corrected correlation of .27 ( Berry, Sackett, & Landers, 2007 ). After reviewing both meta-analyses, it appears that the two studies posed different research questions. Further, there were a number of coding judgments in Berry et al. that merit review, and there was no moderator analysis for educational versus employment interviews. As a result, we reanalyzed the work by Berry et al. and found a corrected correlation of .42 for employment interviews (.15 higher than Berry et al., a 56% increase). Further, educational interviews were associated with a corrected correlation of .21, supporting their influence as a moderator. We suggest a better estimate of the correlation between employment interviews and cognitive ability is .42, and this takes us “back to the future” in that the better overall estimate of the employment interviews – cognitive ability relationship is roughly .40. This difference has implications for what is being measured by interviews and their incremental validity.

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Power-Enhanced Funnel Plots for Meta-Analysis

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000392 ◽

2020 ◽

Vol 228 (1) ◽

pp. 43-49 ◽

Cited By ~ 1

Author(s):

Michael Kossmeier ◽

Ulrich S. Tran ◽

Martin Voracek

Keyword(s):

Statistical Power ◽

Meta Analysis ◽

Relevant Information ◽

Selective Reporting ◽

Graphical Display ◽

Funnel Plot ◽

Evidential Value ◽

Graphical Displays ◽

Funnel Plots ◽

Meta Analyses

Abstract. Currently, dedicated graphical displays to depict study-level statistical power in the context of meta-analysis are unavailable. Here, we introduce the sunset (power-enhanced) funnel plot to visualize this relevant information for assessing the credibility, or evidential value, of a set of studies. The sunset funnel plot highlights the statistical power of primary studies to detect an underlying true effect of interest in the well-known funnel display with color-coded power regions and a second power axis. This graphical display allows meta-analysts to incorporate power considerations into classic funnel plot assessments of small-study effects. Nominally significant, but low-powered, studies might be seen as less credible and as more likely being affected by selective reporting. We exemplify the application of the sunset funnel plot with two published meta-analyses from medicine and psychology. Software to create this variation of the funnel plot is provided via a tailored R function. In conclusion, the sunset (power-enhanced) funnel plot is a novel and useful graphical display to critically examine and to present study-level power in the context of meta-analysis.

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Which Data to Meta-Analyze, and How?

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000357 ◽

2019 ◽

Vol 227 (1) ◽

pp. 64-82 ◽

Cited By ~ 3

Author(s):

Martin Voracek ◽

Michael Kossmeier ◽

Ulrich S. Tran

Keyword(s):

Empirical Research ◽

Meta Analysis ◽

Curve Analysis ◽

Research Progress ◽

Primary Data ◽

Statistical Procedures ◽

Graphical Displays ◽

Primary Data Analysis ◽

Meta Analyses ◽

Data Analytic

Abstract. Which data to analyze, and how, are fundamental questions of all empirical research. As there are always numerous flexibilities in data-analytic decisions (a “garden of forking paths”), this poses perennial problems to all empirical research. Specification-curve analysis and multiverse analysis have recently been proposed as solutions to these issues. Building on the structural analogies between primary data analysis and meta-analysis, we transform and adapt these approaches to the meta-analytic level, in tandem with combinatorial meta-analysis. We explain the rationale of this idea, suggest descriptive and inferential statistical procedures, as well as graphical displays, provide code for meta-analytic practitioners to generate and use these, and present a fully worked real example from digit ratio (2D:4D) research, totaling 1,592 meta-analytic specifications. Specification-curve and multiverse meta-analysis holds promise to resolve conflicting meta-analyses, contested evidence, controversial empirical literatures, and polarized research, and to mitigate the associated detrimental effects of these phenomena on research progress.

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