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Effects of time-restricted eating on markers of glucose metabolism and regulation in individuals with prediabetes or type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials.

AIMS/HYPOTHESIS: This systematic review and meta-analysis aimed to investigate the effects of time-restricted eating (TRE) on glucose metabolism and regulation in individuals with prediabetes (fasting blood glucose of 5.6-6.9 mmol/l or HbA1c of 39-47 mmol/mol [5.7-6.4%]) or type 2 diabetes (fasting blood glucose &#x2265;7 mmol/l or HbA1c &#x2265;48 mmol/mol [6.5%]). METHODS: A literature search was performed in MEDLINE, Embase and CENTRAL from inception to 5 August 2025. Moreover, forward and backward citation searches were performed. Eligible studies were RCTs in adults with prediabetes or type 2 diabetes, lasting &#x2265;2 weeks, reporting markers of glucose metabolism and regulation, comparing TRE (&#x2264;12 h eating window) with a non-time-restricted control diet. Studies involving pregnancy, other fasting regimens, or non-peer-reviewed publications were excluded. Data were pooled as weighted mean differences with 95% CIs using random-effects generic inverse variance models in Cochrane Review Manager Web, and results are presented as forest plots. The certainty of evidence was defined using Grading of Recommendations, Assessment, Development and Evaluations methodology, and risk of bias was estimated by using the Revised Cochrane risk-of-bias tool for randomised trials (RoB 2). RESULTS: Out of 2043 records identified through the database search, as well as 1249 from forward and backward citation searches, ten RCTs including 599 participants were included. The mean length of the studies was 4 months, and the eating windows ranged from 4 to 10 h per day. The pooled meta-analysis showed no overall effect of TRE on HbA1c (-3.33 mmol/mol; 95% CI -6.87, 0.20 (-0.30% points; -0.63, 0.02); p=0.06, moderate certainty). Nevertheless, following stratification by subgroups, TRE resulted in a reduction in HbA1c of 0.93 mmol/mol (-1.70, -0.17 [-0.09% points; -0.16, -0.02]; p=0.02) in individuals with prediabetes but not in individuals with type 2 diabetes (-4.68 mmol/mol; -10.08, 0.72 (-0.43% points; -0.92, 0.07); p=0.09). TRE reduced fasting blood glucose in the pooled analysis (-0.30 mmol/l; -0.53, -0.07; p<0.01, moderate certainty) as well as in the subgroup analyses in individuals with prediabetes (-0.14 mmol/l; -0.27, -0.01; p=0.03) and with type 2 diabetes (-0.48 mmol/l; -0.78, -0.17; p<0.01). Moreover, TRE lowered body weight by 1.6 kg (-2.2, -1.0; p<0.001) in the pooled analysis. The evidence was limited by imprecision arising from wide confidence intervals in some of the included studies, which may be due to small sample sizes. Lastly, the effects of TRE on markers of insulin sensitivity, beta cell function and continuous glucose monitoring measurements were inconclusive. CONCLUSIONS/INTERPRETATION: Moderate-certainty evidence indicates that TRE reduces fasting blood glucose but not HbA1c. The subgroup analyses revealed that TRE improved HbA1c and fasting glucose in individuals with prediabetes and improved fasting glucose in individuals with type 2 diabetes. Future large-scale studies should investigate long-term effects of TRE in prevention and treatment of type 2 diabetes. TRIAL REGISTRATION: PROSPERO CRD42024523591 FUNDING: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Three authors (JS, A-DT, THA) are employed at Steno Diabetes Center Copenhagen, a public hospital and research institution under the Capital Region of Denmark, partly funded by a grant from the Novo Nordisk Foundation.

Humans↗

Instructing adolescents with learning disabilities: converting a meta-analysis to practice.

A previous meta-analysis indicated that eight instructional factors--Questioning, Sequencing and Segmentation, Skill Modeling, Organization and Explicit Practice, Small-Group Setting, Indirect Teacher Activities (e.g., homework), Technology, and Scaffolding-captured the majority of successful intervention programs for adolescents with learning disabilities (LD). Most important was the Organization/Explicit factor, which contributed significant variance (16%) to effect size. This factor included two important instructional components: advance organization and explicit practice. In this article, we convert these findings into practical guidelines to direct instructional practice.

Adolescent↗

Bacterial vaginosis in pregnancy and the risk of prematurity: a meta-analysis.

OBJECTIVE: We conducted this meta-analysis to determine the magnitude of risk conferred by bacterial vaginosis during pregnancy on preterm delivery. SEARCH STRATEGY: We selected articles from a combination of the results of a MEDLINE search (1966-1996), a manual search of bibliographies, and contact with leading researchers. SELECTION CRITERIA: We included case control and cohort studies evaluating the risk of preterm delivery, low birth weight, preterm premature rupture of membranes, or preterm labor for pregnant women who had bacterial vaginosis and those who did not. DATA COLLECTION AND ANALYSIS. Two investigators independently conducted literature searches, applied inclusion criteria, performed data extraction, and critically appraised included studies. Summary estimates of risk were calculated as odds ratios (ORs) using the fixed and random effects models. MAIN RESULTS: We included 19 studies in the final analysis. Bacterial vaginosis during pregnancy was associated with a statistically significant increased risk for all outcomes evaluated. In the subanalyses for preterm delivery, bacterial vaginosis remained a significant risk factor. Pooling adjusted ORs yielded a 60% increased risk of preterm delivery given the presence of bacterial vaginosis. CONCLUSIONS: Bacterial vaginosis is an important risk factor for prematurity and pregnancy morbidity. Further studies will help clarify the benefits of treating bacterial vaginosis and the potential role of screening during pregnancy.

Anti-Bacterial Agents↗

Heart healthy eating behaviors of children following a school-based intervention: a meta-analysis.

The purpose of this meta-analysis was to estimate the effects of school-based interventions on heart healthy eating behaviors of fourth and fifth grade students. The overall effect size (d value) across 12 studies was .24. The 95% confidence interval ranged from .174 to .301. It can be concluded that the school-based cardiovascular health promotion programs had a significant effect on the heart healthy eating behaviors of student participants. Recommendations include identification of reliable measures and inclusion of culturally diverse populations in future studies.

Child↗

A critical review of cancer epidemiology in the petroleum industry, with a meta-analysis of a combined database of more than 350,000 workers.

In 1989 we published a critical review of cancer epidemiology in petroleum workers, which included as a component of the review a meta-analysis by cancer site. Subsequently we have completed three additional reviews and meta-analyses on cell-type-specific leukemias (1995), multiple myeloma (1997), and non-Hodgkin's lymphoma (2000). The objective of the present investigation was to update our 1989 review and meta-analysis of nonlymphohematopoietic cancers in cohort studies of petroleum workers. Included in the present investigation were cohort studies of petroleum workers from the United States, the United Kingdom, Canada, Australia, Finland, Sweden, and Italy. Individual studies were reviewed with regard to specific cancer sites. For each cancer of interest, risk ratios from the individual studies were presented. In some studies, subcohort analyses stratified by exposure parameters such as length of employment, job category, and hire year were also reported. These subcohort or stratified analyses were reviewed and the results of these analyses were taken into consideration in our interpretation. In addition to the qualitative review of individual studies, a meta-analysis was performed to combine data from individual cohort studies of petroleum workers. The primary purpose of the meta-analysis was to provide a summary measure of risk for each cancer site. Based on a review and meta-analyses of cohort studies of more than 350,000 petroleum workers in the United States, the United Kingdom, Canada, Australia, Finland, Sweden, and Italy, we concluded that there was no increased mortality from digestive cancers (stomach, large intestine, liver, or pancreas), lung cancer, bladder cancer, kidney cancer, or brain cancer. The summary standardized mortality ratios for these cancer sites were all below unity. Significant increases of melanoma mortality were reported in some small groups of refinery workers in the United Kingdom and upstream operation workers in Canada, but no responsible agent(s) had been identified. The observed mortality from skin cancer in all other studies was similar to the expected. In particular, no significant increase of skin cancer mortality was reported in any of the U.S. studies. Elevated mortality from prostate cancer was noted in short-term workers at a U.S. refinery and in short-term workers employed in certain crafts at U.S. crude oil operations. However, the absence of an upward trend by length of employment in these workers argued against an association between exposure to petroleum products and prostate cancer. For all petroleum workers as a whole, mortality from prostate cancer was as expected.

Australia↗

Why do semantic priming effects increase in old age? A meta-analysis.

This study reports a meta-analysis comparing the size of semantic priming effects on young and older adults' lexical decision and pronunciation latency. The analysis included 15 studies with 49 conditions varying the semantic relatedness of a prime stimulus (single word or whole sentence) and a target word. An effect-size analysis on the difference between young and older adults' semantic priming effect (unrelated minus related latency) indicated that semantic priming effects are reliably larger for older than for young adults. There was no evidence for nonhomogeneity in this age difference across the different conditions. The relationship between young and older adults' semantic priming effects was described by a function with a positive intercept and a slope of 1.0. This pattern of findings favors aging models postulating process-specific slowing rather than general cognitive slowing.

Adult↗

Aging and verbal memory span: a meta-analysis.

Using Brinley plots, this meta-analysis provides a quantitative examination of age differences in eight verbal span tasks. The main conclusions are these: (a) there are age differences in all verbal span tasks; (b) the data support the conclusion that working memory span is more age sensitive than short-term memory span; and (c) there is a linear relationship between span of younger adults and span of older adults. A linear model indicates the presence of three distinct functions, in increasing order of size of age effects: simple storage span; backward digit span; and working memory span.

Adult↗

Among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth dependent on the type of analogue used? A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to answer the following clinical question: among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth per randomized patient dependent on the type of analogue used? Eligible studies were randomized controlled trials (RCTs), published as a full manuscript in a peer-reviewed journal, that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared. A literature search identified 22 RCTs comparing GnRH antagonists and GnRH agonists that involved 3176 subjects. Where live birth was not reported in a study that fulfilled the inclusion criteria, an effort was made to contact the corresponding authors to retrieve the missing information. If this was not possible, the reported outcome measure, clinical pregnancy or ongoing pregnancy was converted to live birth in 12 studies using published data (Arce et al., 2005). No significant difference was present in the probability of live birth between the two GnRH analogues [odds ratio (OR), 0.86; 95% confidence intervals (CI), 0.72 to 1.02]. This result remains stable in subgroup analysis that ordered the studies by type of population studied, gonadotrophin type used for stimulation, type of agonist protocol used, type of agonist used, type of antagonist protocol used, type of antagonist used, presence of allocation concealment, presence of co-intervention and the way the information on live birth was retrieved. In conclusion, the probability of live birth after ovarian stimulation for IVF does not depend on the type of analogue used for pituitary suppression.

Female↗

Is all-rac-alpha-tocopherol different from RRR-alpha-tocopherol regarding cardiovascular efficacy? A meta-analysis of clinical trials.

A meta-analysis of 14 clinical studies with RRR- or all-rac-alpha-tocopherol (83,800 subjects) was performed to evaluate whether RRR and all-rac differ in cardiovascular efficacy based on those clinical endpoints that are most consistently documented in the publications of the studies. Odds ratios of treatment versus control for individual studies and for studies pooled by form were centered around unity, with no significant differences between vitamin E forms. The results corroborate the present opinion that vitamin E supplements up to 800 mg/d for up to 6.5 years are safe.

Cardiovascular Diseases↗

The characteristics of persistent sexual offenders: a meta-analysis of recidivism studies.

A meta-analysis of 82 recidivism studies (1,620 findings from 29,450 sexual offenders) identified deviant sexual preferences and antisocial orientation as the major predictors of sexual recidivism for both adult and adolescent sexual offenders. Antisocial orientation was the major predictor of violent recidivism and general (any) recidivism. The review also identified some dynamic risk factors that have the potential of being useful treatment targets (e.g., sexual preoccupations, general self-regulation problems). Many of the variables commonly addressed in sex offender treatment programs (e.g., psychological distress, denial of sex crime, victim empathy, stated motivation for treatment) had little or no relationship with sexual or violent recidivism.

Humans↗

Meta-analysis of desipramine as an adjunct in the treatment of cocaine addiction.

Many pharmacologic regimens have been recommended as supplemental treatment strategies for cocaine abuse. Using the technique of meta-analysis, we compared and combined the data from six studies to examine the efficacy of desipramine as an adjunctive treatment approach for cocaine addiction. These studies were randomized, placebo-controlled clinical trials of desipramine and involved a total of 200 cocaine-addicted patients. We found that desipramine is no better than placebo in retaining patients in treatment. However, while patients are in treatment, desipramine is helpful in promoting abstinence (p less than 0.001). There were several compromises made to use meta-analysis for these studies. These included comparing patient populations with different psychiatric and substance use diagnoses, comparing studies that used varying amounts of psychotherapy, and comparing studies that defined certain outcome variables in diverse ways. There are other limitations in the use of meta-analysis that were not specific to the studies we compared. These include such issues as statistical bias and publication bias. The purpose of this paper is to suggest the use of meta-analysis as one way to help the clinician evaluate the literature and to point out the areas of difficulty when assessing the literature.

Cocaine↗

Antibiotics to prevent infection of simple wounds: a meta-analysis of randomized studies.

A meta-analysis was conducted to determine whether prophylactic systemic antibiotics prevent infection in patients with nonbite wounds that are managed in the emergency department (ED). A literature search was performed to identify published, randomized trials of prophylactic antibiotics for nonbite wounds. Blinded review of trial methods was used to select trials that randomly assigned patients to antibiotic or control groups and analyzed results by intention to treat. Of 9 randomized trials, 7 (with 1,734 study subjects) were accepted for analysis. The odds ratio for infection in treated patients compared with controls was used as the measure of effect, and a summary odds ratio was calculated. Patients treated with antibiotics had a slightly greater incidence of infection compared with untreated controls: odds ratio 1.16 (95% confidence interval [CI] 0.77 to 1.78). Even among patients treated with a penicillinase-resistant antibiotic (5 trials with 1,204 patients), there was no benefit from treatment; odds ratio 1.00 (95% CI 0.59 to 1.71). In conclusion, there is no evidence in published trials that prophylactic antibiotics offer protection against infection of nonbite wounds in patients treated in EDs.

Anti-Bacterial Agents↗

Predicting workplace aggression: a meta-analysis.

The authors conducted a meta-analysis of 57 empirical studies (59 samples) concerning enacted workplace aggression to answer 3 research questions. First, what are the individual and situational predictors of interpersonal and organizational aggression? Second, within interpersonal aggression, are there different predictors of supervisor- and coworker-targeted aggression? Third, what are the relative contributions of individual (i.e., trait anger, negative affectivity, and biological sex) and situational (i.e., injustice, job dissatisfaction, interpersonal conflict, situational constraints, and poor leadership) factors in explaining interpersonal and organizational aggression? Results show that both individual and situational factors predict aggression and that the pattern of predictors is target specific. Implications for future research are discussed.

Aggression↗

Cardiovascular reactivity and family history of hypertension: a meta-analysis.

A regression-based meta-analysis examined the degree to which the effects of a family history of hypertension on cardiovascular reactivity are moderated by the magnitude of cardiovascular responses elicited in challenge/task conditions. Mean change scores for negative family history groups were regressed on mean change scores for positive family history groups. The slopes of separate regression lines obtained for systolic and diastolic blood pressure and heart rate were significantly less than 1.0 and the y-intercepts for these regression lines were significantly greater than zero. This pattern indicates that family history differences in cardiovascular reactivity to stress are greatest in situations that elicit the smallest baseline-stressor change scores in non-family-history groups.

Blood Pressure↗

Reaction time slowing in adults with HIV: results of a meta-analysis using brinley plots.

A meta-analysis in the form of Brinley plots was conducted on the mean reaction times of HIV+ and HIV- groups. HIV+ reaction times were regressed on HIV- reaction times across 122 task conditions from 29 studies, producing a highly linear function (r(2) = .94), with a slope b = 1.039, which was not significantly different than b = 1.00. Asymptomatic and symptomatic HIV+ reaction times were also separately regressed on HIV- reaction times across 67 task conditions from 13 studies. Both functions were highly linear (r(2) = .97 and.90 respectively), with slopes of 1.034 and 1.117 respectively. Only the slope for symptomatic HIV+ groups was significantly larger than b = 1.00, suggesting a modest generalized slowing of cognition in these adults.

Adult↗

High-Flow Nasal Oxygen Versus Conventional Oxygen Therapy and Non-Invasive Ventilation for Acute Respiratory Failure in the Emergency Department: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis compares the use of high-flow nasal oxygen (HFNO) with conventional oxygen therapy (COT) and non-invasive ventilation (NIV) in the management of acute respiratory failure (ARF) in the emergency department (ED). A comprehensive search of relevant sources was undertaken. Randomised controlled trials (RCTs) assessing adult patients (&#x2265;&#x2009;18&#x2009;years) treated in the ED for ARF and comparing HFNO to COT/NIV were included. The primary outcome was the need for endotracheal intubation and mechanical ventilation (IMV). Secondary outcomes included physiological and biochemical parameters, ICU admission, hospital length of stay, dyspnoea scores and mortality. A total of 17 RCTs (1955 patients) were included. There was a significant reduction in IMV favouring the HFNO group compared to COT and NIV (RR 0.64, 95% CI 0.47-0.88). HFNO showed significant improvements in RR, SpO2, PaO2 and Modified Borg Dyspnoea Scale. Subgroup analysis showed reduced rates of IMV with HFNO compared to COT (RR 0.61, 95% CI 0.41-0.91), but not compared to NIV (RR 0.69, 95% CI 0.42-1.14). HFNO additionally showed a reduction of IMV compared to NIV and COT in undifferentiated patients (RR 0.61, 95% CI 0.41-0.93), but not in exacerbations of COPD or acute heart failure. Ten of the 17 studies had at least some concern for risk of bias, with several analyses having notable heterogeneity. HFNO showed a significant reduction in rates of IMV, improvement in peripheral oxygen saturations, PaO2, respiratory rate and patient dyspnoea scores compared to COT and NIV.

Humans↗

Task versus relationship conflict, team performance, and team member satisfaction: a meta-analysis.

This study provides a meta-analysis of research on the associations between relationship conflict, task conflict, team performance, and team member satisfaction. Consistent with past theorizing, results revealed strong and negative correlations between relationship conflict, team performance, and team member satisfaction. In contrast to what has been suggested in both academic research and introductory textbooks, however, results also revealed strong and negative (instead of the predicted positive) correlations between task conflict team performance, and team member satisfaction. As predicted, conflict had stronger negative relations with team performance in highly complex (decision making, project, mixed) than in less complex (production) tasks. Finally, task conflict was less negatively related to team performance when task conflict and relationship conflict were weakly, rather than strongly, correlated.

Conflict, Psychological↗

Information processing deficits associated with developmental coordination disorder: a meta-analysis of research findings.

A meta-analysis was conducted to identify information processing factors that characterise children with Developmental Coordination Disorder (DCD). A total of 50 studies yielded 374 effect sizes based on 983 DCD and 987 control children. A mild generalised performance deficit was indicated, since motor-impaired children were inferior on almost all measures of information processing. There were, however, several areas where their deficiencies were more pronounced. The greatest deficiency was in visual-spatial processing. This was evident regardless of whether or not the tasks involved a motor component. Most other deficiencies were in the small-to-moderate range and included kinaesthetic and cross-modal processing. The findings support the notion that perceptual problems, particularly in the visual modality, are associated with difficulties in motor coordination.

Child↗