-
Advances in Nutrition (Bethesda, Md.) Sep 2023Ghrelin is an orexigenic hormone primarily released by the stomach and has 2 isoforms: acylated ghrelin (AG) and de-acylated ghrelin (DAG), that appear to have different... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Ghrelin is an orexigenic hormone primarily released by the stomach and has 2 isoforms: acylated ghrelin (AG) and de-acylated ghrelin (DAG), that appear to have different functions in humans.
OBJECTIVES
To perform a systematic review and meta-analysis of the association between plasma concentrations of total ghrelin (TG), AG, and DAG and perceptions of hunger in healthy adults.
METHODS
The following criteria were used for inclusion: 1) sample contained adults ≥18 y of age, 2) body mass index [BMI kg/m] was ≥18.5, 3) ghrelin was sampled through blood, 4) subjective hunger was measured on a validated scale, 5) study reported a Pearson product correlation of ghrelin or had relevant figure(s) for data extraction, 6) participants were healthy with no overt disease, 7) protocols contained no physical activity or weight loss medication that suppressed appetite, 8) interventions were conducted without environmental manipulations. Moderators assessed were age, BMI, percentage of body fat (%BF), macronutrient content of test meals, energy intake (kcals), sex, and ghrelin isoform (AG, DAG, or TG).
RESULTS
The analysis included 47 studies (110 trials, n = 1799, age: 31.4 ± 12.0 y, BMI: 26.0 ± 4.75 kg/m) and measured AG (n = 47 trials), DAG (n = 12 trials), and TG (n = 51 trials). The overall model indicated that ghrelin concentrations and perceptions of hunger were moderately correlated (r = 0.43, P < 0.001), and ghrelin isoform significantly moderated this relationship (AG: r = 0.60, P < 0.001; TG: r = 0.215, P = 0.01; DAG: r = 0.53, P = 0.695). Other significant moderators included age (b = -0.02, P = 0.01), BMI (b = -0.03, P = 0.05), %BF (b = -0.03, P = 0.05), energy intake (b = 0.0003, P = 0.04), and percentage of carbohydrates of test meals (b = 0.008, P = 0.05).
CONCLUSIONS
Ghrelin is associated with perceptions of hunger in humans, and this relationship is strengthened when AG is isolated; thus, AG may have a large impact on hunger signals in various populations. Future research should attempt to understand the role of DAG in hunger sensations.
Topics: Adult; Humans; Young Adult; Child, Preschool; Hunger; Ghrelin; Energy Intake; Body Mass Index; Perception; Appetite
PubMed: 37536563
DOI: 10.1016/j.advnut.2023.07.011 -
Molecular Autism Mar 2023Suicidality is highly prevalent in autistic people without co-occurring intellectual disabilities, and high autistic traits are found in adults who have attempted... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Suicidality is highly prevalent in autistic people without co-occurring intellectual disabilities, and high autistic traits are found in adults who have attempted suicide. However, prevalence rates for both autistic and possibly autistic people have not been synthesised meta-analytically.
AIMS
To (1) calculate pooled prevalence estimates of suicidality in autistic people and possibly autistic people without co-occurring intellectual disability; (2) evaluate the influence of participant and study level characteristics on heterogeneity; and (3) determine the quality of evidence.
METHODS
Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. PsycINFO, Embase, MEDLINE and Web of Science were systematically searched from 1992 to January 25, 2022. Empirical quantitative studies reporting prevalence of suicidal ideation, suicide plans, or suicide attempts and behaviours were considered for inclusion. Random effects models were used to estimate pooled prevalence of each suicidality outcome with 95% confidence intervals. Heterogeneity was explored using sensitivity and moderator analyses.
RESULTS
Data from 48,186 autistic and possibly autistic participants in 36 primary studies were meta-analysed. Pooled prevalence of suicidal ideation was 34.2% (95% CI 27.9-40.5), suicide plans 21.9% (13.4-30.4), and suicidal attempts and behaviours 24.3% (18.9-29.6). High levels of heterogeneity (I > 75) were observed in all three analyses. Estimates did not differ between autistic or possibly autistic samples. Geographical location (p = 0.005), transgender or gender non-conforming samples (p < 0.001) and type of report (p < 0.001) significantly moderated suicidal ideation, whereas age group (p = 0.001) and measure of suicidality (p = 0.001) significantly moderated suicide plans. There was a significant association between the proportion of male participants and prevalence of suicide plans, with a decrease in the proportion of males for every unit change of suicide plan prevalence (p = 0.013). No variables were found to moderate estimates of suicide attempts and behaviours.
CONCLUSIONS
The results confirm suicidality is highly prevalent in both autistic and possibly autistic people without co-occurring intellectual disability and highlights potential moderators. Possibly autistic individuals require more attention in clinical and research considerations going forward to further understand and prevent suicide in both groups.
Topics: Adult; Humans; Male; Suicidal Ideation; Intellectual Disability; Autistic Disorder; Suicide; Suicide, Attempted
PubMed: 36922899
DOI: 10.1186/s13229-023-00544-7 -
Sports Medicine (Auckland, N.Z.) Sep 2023Augmented feedback is often used during resistance training to enhance acute physical performance and has shown promise as a method of improving chronic physical... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Augmented feedback is often used during resistance training to enhance acute physical performance and has shown promise as a method of improving chronic physical adaptation. However, there are inconsistencies in the scientific literature regarding the magnitude of the acute and chronic responses to feedback and the optimal method with which it is provided.
OBJECTIVE
This systematic review and meta-analysis aimed to (1) establish the evidence for the effects of feedback on acute resistance training performance and chronic training adaptations; (2) quantify the effects of feedback on acute kinematic outcomes and changes in physical adaptations; and (3) assess the effects of moderating factors on the influence of feedback during resistance training.
METHODS
Twenty studies were included in this systematic review and meta-analysis. This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Four databases were searched, and studies were included if they were peer-reviewed investigations, written in English, and involved the provision of feedback during or following dynamic resistance exercise. Furthermore, studies must have evaluated either acute training performance or chronic physical adaptations. Risk of bias was assessed using a modified Downs and Black assessment tool. Multilevel meta-analyses were performed to quantify the effects of feedback on acute and chronic training outcomes.
RESULTS
Feedback enhanced acute kinetic and kinematic outputs, muscular endurance, motivation, competitiveness, and perceived effort, while greater improvements in speed, strength, jump performance, and technical competency were reported when feedback was provided chronically. Furthermore, greater frequencies of feedback (e.g., following every repetition) were found to be most beneficial for enhancing acute performance. Results demonstrated that feedback improves acute barbell velocities by approximately 8.4% (g = 0.63, 95% confidence interval [CI] 0.36-0.90). Moderator analysis revealed that both verbal (g = 0.47, 95% CI 0.22-0.71) and visual feedback (g = 1.11, 95% CI 0.61-1.61) were superior to no feedback, but visual feedback was superior to verbal feedback. For chronic outcomes, jump performance might have been positively influenced (g = 0.39, 95% CI - 0.20 to 0.99) and short sprint performance was likely enhanced (g = 0.47, 95% CI 0.10-0.84) to a greater extent when feedback is provided throughout a training cycle.
CONCLUSIONS
Feedback during resistance training can lead to enhanced acute performance within a training session and greater chronic adaptations. Studies included in our analysis demonstrated a positive influence of feedback, with all outcomes showing superior results than when no feedback is provided. For practitioners, it is recommended that high-frequency, visual feedback is consistently provided to individuals when they complete resistance training, and this may be particularly useful during periods of low motivation or when greater competitiveness is beneficial. Alternatively, researchers must be aware of the ergogenic effects of feedback on acute and chronic responses and ensure that feedback is standardised when investigating resistance training.
Topics: Humans; Resistance Training; Muscle Strength; Exercise; Adaptation, Physiological; Acclimatization
PubMed: 37410360
DOI: 10.1007/s40279-023-01877-2 -
Schizophrenia Research. Cognition Mar 2022In schizophrenia, impairments in neurocognition (NC) and social cognition (SC) are associated with reduced functional capacity (FC) and poor real-world functioning... (Review)
Review
In schizophrenia, impairments in neurocognition (NC) and social cognition (SC) are associated with reduced functional capacity (FC) and poor real-world functioning (RWF). In this semi-systematic review, we examined this association across a range of research questions. We conducted a systematic search in Embase and MEDLINE from 2005 to 2019, and conducted additional pragmatic searches. After screening of titles, abstracts and full-texts, we included 564 citations, of which 44 (26 primary studies, 15 systematic reviews and 3 narrative reviews) were prioritized for reporting. Both NC and SC were significantly associated with functioning, with slightly stronger association for SC. Effect sizes were generally larger for FC than for RWF. NC showed stronger associations with occupational functioning and independent living, and SC with social functioning. Baseline cognition predicted long-term RWF up to 20 years of follow-up, though long-term data were limited for SC. Cognitive remediation improved RWF functioning, especially when it was combined with psychosocial rehabilitation. SC mediated the relationship of NC with functioning. Negative symptoms appeared to mediate and moderate the association of cognition with functioning. Other factors involved included severity of cognitive dysfunction, metacognition, depression and choice of RWF instrument. We discuss potential implications for studies of pharmacological cognitive interventions in schizophrenia - the relevance of both NC and SC, the advantage of adjunctive psychosocial rehabilitation, the role of relevant moderating and mediating variables, and the challenges with RWF instrument selection. Successful cognitive interventions could allow patients with schizophrenia to improve their potential for community functioning.
PubMed: 34631435
DOI: 10.1016/j.scog.2021.100217 -
Journal of Anxiety Disorders Mar 2021This systematic review and meta-analysis aimed to clarify the association between social anxiety and affective (AE) and cognitive empathy (CE). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This systematic review and meta-analysis aimed to clarify the association between social anxiety and affective (AE) and cognitive empathy (CE).
METHODS
1442 studies from PsycINFO, Medline, and EMBASE (inception-January 2020) were systematically reviewed. Included studies (N = 48) either predicted variance in empathy using social anxiety scores or compared empathy scores between socially anxious individuals and a control group.
RESULTS
Social anxiety and AE were statistically significantly positively associated, k = 14, r = .103 (95%CI [.003, .203]), z = 2.03, p = .043. Sex (Q (2) = 18.79, p < .0001), and type of measures (Q (1 = 7.34, p = .007) moderated the association. Correlations were significant for male samples (r = .316, (95%CI [.200, .432])) and studies using self-report measures (r = .162 (95%CI [.070, .254])). Overall, social anxiety and CE were not significantly associated, k = 52, r =-.021 (95%CI [-.075, .034]), z= -0.74, p = .459. Sample type moderated the association (Q (1) = 5.03, p < .0001). For clinical samples the association was negative (r= -.112, (95%CI [-.201, -.017]).
CONCLUSION
There was evidence for a positive association between social anxiety and AE, but future studies are needed to verify the moderating roles of sex and type of measure. Besides, low CE might only hold for patients with SAD.
Topics: Anxiety; Empathy; Fear; Humans; Male; Self Report
PubMed: 33588287
DOI: 10.1016/j.janxdis.2021.102357 -
Sports Medicine (Auckland, N.Z.) Apr 2024Running economy is defined as the energy demand at submaximal running speed, a key determinant of overall running performance. Strength training can improve running... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Running economy is defined as the energy demand at submaximal running speed, a key determinant of overall running performance. Strength training can improve running economy, although the magnitude of its effect may depend on factors such as the strength training method and the speed at which running economy is assessed.
AIM
To compare the effect of different strength training methods (e.g., high loads, plyometric, combined methods) on the running economy in middle- and long-distance runners, over different running speeds, through a systematic review with meta-analysis.
METHODS
A systematic search was conducted across several electronic databases including Web of Science, PubMed, SPORTDiscus, and SCOPUS. Using different keywords and Boolean operators for the search, all articles indexed up to November 2022 were considered for inclusion. In addition, the PICOS criteria were applied: Population: middle- and long-distance runners, without restriction on sex or training/competitive level; Intervention: application of a strength training method for ≥ 3 weeks (i.e., high loads (≥ 80% of one repetition maximum); submaximal loads [40-79% of one repetition maximum); plyometric; isometric; combined methods (i.e., two or more methods); Comparator: control group that performed endurance running training but did not receive strength training or received it with low loads (< 40% of one repetition maximum); Outcome: running economy, measured before and after a strength training intervention programme; Study design: randomized and non-randomized controlled studies. Certainty of evidence was assessed with the GRADE approach. A three-level random-effects meta-analysis and moderator analysis were performed using R software (version 4.2.1).
RESULTS
The certainty of the evidence was found to be moderate for high load training, submaximal load training, plyometric training and isometric training methods and low for combined methods. The studies included 195 moderately trained, 272 well trained, and 185 highly trained athletes. The strength training programmes were between 6 and 24 weeks' duration, with one to four sessions executed per week. The high load and combined methods induced small (ES = - 0.266, p = 0.039) and moderate (ES = - 0.426, p = 0.018) improvements in running economy at speeds from 8.64 to 17.85 km/h and 10.00 to 14.45 km/h, respectively. Plyometric training improved running economy at speeds ≤ 12.00 km/h (small effect, ES = - 0.307, p = 0.028, β = 0.470, p = 0.017). Compared to control groups, no improvement in running economy (assessed speed: 10.00 to 15.28 and 9.75 to 16.00 km/h, respectively) was noted after either submaximal or isometric strength training (all, p > 0.131). The moderator analyses showed that running speed (β = - 0.117, p = 0.027) and VOmax (β = - 0.040, p = 0.020) modulated the effect of high load strength training on running economy (i.e., greater improvements at higher speeds and higher VOmax).
CONCLUSIONS
Compared to a control condition, strength training with high loads, plyometric training, and a combination of strength training methods may improve running economy in middle- and long-distance runners. Other methods such as submaximal load training and isometric strength training seem less effective to improve running economy in this population. Of note, the data derived from this systematic review suggest that although both high load training and plyometric training may improve running economy, plyometric training might be effective at lower speeds (i.e., ≤ 12.00 km/h) and high load strength training might be particularly effective in improving running economy (i) in athletes with a high VOmax, and (ii) at high running speeds.
PROTOCOL REGISTRATION
The original protocol was registered ( https://osf.io/gyeku ) at the Open Science Framework.
Topics: Humans; Resistance Training; Running; Athletic Performance; Plyometric Exercise; Physical Endurance; Muscle Strength
PubMed: 38165636
DOI: 10.1007/s40279-023-01978-y -
Journal of Medical Internet Research Dec 2023Caregiving can affect people of all ages and can have significant negative health impacts on family caregivers themselves. Research has shown that social support acts as... (Review)
Review
BACKGROUND
Caregiving can affect people of all ages and can have significant negative health impacts on family caregivers themselves. Research has shown that social support acts as a buffer against many negative health impacts. A common source of social support is support groups. Although traditionally, these groups were conducted in a face-to-face setting, the advent of the internet, social media applications, and the smartphone have seen online support groups (OSGs) develop as a space where many caregivers seek support. The number of OSGs has increased exponentially, but there is no clear consensus on what factors or characteristics of OSGs contribute to social support development within them or what types of OSGs are available to family caregivers.
OBJECTIVE
This study aimed to conduct a scoping review to contribute to the understanding of the types and characteristics of OSGs for family caregivers.
METHODS
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines, the CINAHL, PsychInfo, Psych Articles, Social Sciences, Communication Source, Medline, and Web of Science databases were searched for studies (caregiver focused, adults aged 18 years or older, online social support groups, caring for a living person, peer-reviewed journal publications on empirical research). In total, 19 studies were included in the review. The research questions were (1) what type of social support groups are online for adult family caregivers, (2) what the communication mediums and characteristics of these OSGs are, and (3) what psychosocial or other factors make OSGs successful or unsuccessful for participants.
RESULTS
In response to the first research question, we found that the majority of OSGs took place on public text-based forums and were illness specific. Where demographics were reported, participants were predominately women, White, and working with university-level education. There were a variety of caregiving relationships. For the second research question, the most common communication medium found was text-based communication, with the use of emojis, photos, and GIF (Graphics Interchange Format) files as part of these exchanges. Most frequently, the OSGs were asynchronous with a degree of anonymity, not time-limited by the frequency of contact or duration, and moderated by peer or professional moderators or facilitators. Results for the third research question explored the overarching categories of safe communication and engagement and group management. These described successful OSGs as having a focus on similar others with shared lived experiences communicated in a nonjudgmental space overseen by trained peer or professional facilitators.
CONCLUSIONS
There are several key considerations for OSGs to be successful for family caregivers. A general recommendation for practitioners is to give importance to building active moderation and multifaceted structures of support to meet different levels of caregiver needs and the ability to engage.
Topics: Adult; Humans; Female; Caregivers; Self-Help Groups; Social Support; Health Services; Communication; Family
PubMed: 38090796
DOI: 10.2196/46858 -
JAMA Network Open Feb 2024Physical activity is associated with the risk for cognitive decline, but much of the evidence in this domain comes from studies with short follow-ups, which is prone to... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Physical activity is associated with the risk for cognitive decline, but much of the evidence in this domain comes from studies with short follow-ups, which is prone to reverse causation bias.
OBJECTIVE
To examine how length of follow-up, baseline age, physical activity amount, and study quality modify the longitudinal associations of physical activity with cognition.
DATA SOURCES
Observational studies of adults with a prospective follow-up of at least 1 year, a valid baseline cognitive measure or midlife cohort, and an estimate of the association of baseline physical activity and follow-up cognition were sought from PsycInfo, Scopus, CINAHL, Web of Science, SPORTDiscus, and PubMed, with the final search conducted on November 2, 2022.
STUDY SELECTION
Two independent researchers screened titles with abstracts and full-text reports.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently assessed study quality and extracted data. Pooled estimates of association were calculated with random-effects meta-analyses. An extensive set of moderators, funnel plots, and scatter plots of physical activity amount were examined. This study is reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.
MAIN OUTCOMES AND MEASURES
Pooled estimates of the associations between physical activity and global cognition, as well as specific cognitive domains, were examined.
RESULTS
A total of 104 studies with 341 471 participants were assessed. Analysis of binary outcomes included 45 studies with 102 452 individuals, analysis of follow-up global cognition included 14 studies with 41 045 individuals, and analysis of change in global cognition included 25 studies with 67 463 individuals. Physical activity was associated with a decreased incidence of cognitive impairment or decline after correction for funnel plot asymmetry (pooled risk ratio, 0.97; 95% CI, 0.97-0.99), but there was no significant association in follow-ups longer than 10 years. Physical activity was associated with follow-up global cognition (standardized regression coefficient, 0.03; 95% CI, 0.02-0.03) and change in global cognition (standardized regression coefficient, 0.01; 95% CI, 0.01 to 0.02) from trim-and-fill analyses, with no clear dose-response or moderation by follow-up length, baseline age, study quality or adjustment for baseline cognition. The specific cognitive domains associated with physical activity were episodic memory (standardized regression coefficient, 0.03; 95% CI, 0.02-0.04) and verbal fluency (standardized regression coefficient, 0.05; 95% CI, 0.03-0.08).
CONCLUSIONS AND RELEVANCE
In this meta-analysis of the association of physical activity with cognitive decline, physical activity was associated with better late-life cognition, but the association was weak. However, even a weak association is important from a population health perspective.
Topics: Humans; Aged; Prospective Studies; Cognitive Dysfunction; Cognition; Exercise; Memory, Episodic
PubMed: 38300618
DOI: 10.1001/jamanetworkopen.2023.54285 -
Clinical Psychology Review Apr 2022Suicidality in autistic youth is a major public health issue. This study aimed to determine global prevalence of, and risk/protective factors for suicidality in autistic... (Meta-Analysis)
Meta-Analysis Review
Suicidality in autistic youth is a major public health issue. This study aimed to determine global prevalence of, and risk/protective factors for suicidality in autistic youth via systematic review and meta-analysis. We systematically searched Embase, PubMed, PsycINFO, Web of Science, and the Cochrane library for studies from inception to November 22nd, 2021. We selected empirical studies reporting on suicide outcomes (i.e., ideation, behaviors, attempts and deaths) in autistic youth (≤25 years). Random effects models were used to estimate the pooled prevalence of suicide outcomes with 95% confidence interval (CI). Heterogeneity was investigated with potential moderators using meta-regression analyses. The final selection included 47 papers, 29 of which were included in meta-analyses and 37 were narratively synthesized (sociodemographic, psychiatric, psychological, other factors, and interventions). The pooled prevalence of suicidal ideation was 25.2% (95% CI 18.2-33.8; i.e., one in four), suicide attempts 8.3% (3.6-18.2), and suicide deaths 0.2% (0.05-0.52). Estimates in self-reports were higher than in parent-reports. Age was a significant but inconsistent moderator on suicide outcomes, but substantial heterogeneity remained. Adverse childhood experiences were strong risk factors for suicidality, while resilience was protective. Participatory suicide risk-assessment, early intervention, and resilience promotion should be primary clinical/research goals.
Topics: Adolescent; Autistic Disorder; Humans; Prevalence; Suicidal Ideation; Suicide; Suicide, Attempted
PubMed: 35290800
DOI: 10.1016/j.cpr.2022.102144 -
Epidemiology and Psychiatric Sciences Mar 2022Lower parental education has been linked to adverse youth mental health outcomes. However, the relationship between parental education and youth suicidal behaviours... (Meta-Analysis)
Meta-Analysis
AIMS
Lower parental education has been linked to adverse youth mental health outcomes. However, the relationship between parental education and youth suicidal behaviours remains unclear. We explored the association between parental education and youth suicidal ideation and attempts, and examined whether sociocultural contexts moderate such associations.
METHODS
We conducted a systematic review and meta-analysis with a systematic literature search in PubMed, PsycINFO, Medline and Embase from 1900 to December 2020 for studies with participants aged 0-18, and provided quantitative data on the association between parental education and youth suicidal ideation and attempts (death included). Only articles published in English in peer-reviewed journals were considered. Two authors independently assessed eligibility of the articles. One author extracted data [e.g. number of cases and non-cases in each parental education level, effect sizes in forms of odds ratios (ORs) or beta coefficients]. We then calculated pooled ORs using a random-effects model and used moderator analysis to investigate heterogeneity.
RESULTS
We included a total of 59 articles (63 study samples, totalling 2 738 374 subjects) in the meta-analysis. Lower parental education was associated with youth suicidal attempts [OR = 1.12, 95% Confidence Interval (CI) = 1.04-1.21] but not with suicidal ideation (OR = 1.05, 95% CI = 0.98-1.12). Geographical region and country income level moderated the associations. Lower parental education was associated with an increased risk of youth suicidal attempts in Northern America (OR = 1.26, 95% CI = 1.10-1.45), but with a decreased risk in Eastern and South-Eastern Asia (OR = 0.72, 95% CI = 0.54-0.96). An association of lower parental education and increased risk of youth suicidal ideation was present in high- income countries (HICs) (OR = 1.14, 95% CI = 1.05-1.25), and absent in low- and middle-income countries (LMICs) (OR = 0.91, 95% CI = 0.77-1.08).
CONCLUSIONS
The association between youth suicidal behaviours and parental education seems to differ across geographical and economical contexts, suggesting that cultural, psychosocial or biological factors may play a role in explaining this association. Although there was high heterogeneity in the studies reviewed, this evidence suggests that the role of familial sociodemographic characteristics in youth suicidality may not be universal. This highlights the need to consider cultural, as well as familial factors in the clinical assessment and management of youth's suicidal behaviours in our increasingly multicultural societies, as well as in developing prevention and intervention strategies for youth suicide.
Topics: Adolescent; Child; Child, Preschool; Educational Status; Humans; Infant; Infant, Newborn; Parents; Poverty; Suicidal Ideation; Suicide
PubMed: 35352676
DOI: 10.1017/S204579602200004X