Effects of selected dietary supplements on migraine prophylaxis: A systematic review and dose-response meta-analysis of randomized controlled trials.

BACKGROUND: The existing evidence on the effect of dietary supplements for preventing migraines has generated conflicting results. METHODS: We assessed alterations in migraine clinical features corresponding to the intake of dietary supplements. Our main outcomes included the frequency (number of attacks), duration (in hours), the severity (intensity) and the monthly migraine days. Using a dose-response meta-analysis, we estimated the dose-dependent impact. The certainty of evidence was evaluated using the GRADE tool. RESULTS: Finally, twenty-two trials were included in the systematic review and meta-analysis. Magnesium supplementation reduced migraine attacks (mean difference (MD) = -2.51), severity (MD = -0.88), and the monthly migraine days (MD = -1.66) compared with the control group. CoQ10 decreased the frequency (MD = -1.73), severity (MD = -1.35), and duration of migraine (MD = -1.72). Riboflavin decreased attack frequency (MD = -1.34). Alpha-lipoic acid decreased attack frequency (MD = -1.24) and severity (MD = -0.38). Probiotics decreased the frequency (MD = -1.16), severity (MD = -1.07) and the monthly migraine days (MD = -3.02). Vitamin D reduced migraine frequency (MD = -1.69) and the monthly migraine days (MD = -2.41). In adults, compared with placebo, these supplements did not significantly affect other outcomes, and omega-3 supplementation did not yield a statistically significant reduction in any of these outcomes. CONCLUSION: The use of certain dietary supplements has resulted in a significant decrease in migraine prophylaxis. Further clinical trials of high quality appear to be beneficial.

Postoperative pain and neurocognitive outcomes after noncardiac surgery: a systematic review and dose-response meta-analysis.

BACKGROUND: Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common after noncardiac surgery. Postsurgical pain is frequent and can persist as chronic postsurgical pain (CPSP). The association between postsurgical pain and POD or POCD is biologically plausible. We conducted this systematic review to evaluate the association between acute postsurgical pain or CPSP and POD or POCD in adults undergoing noncardiac surgery. METHODS: We followed Preferred Reporting Items for Systematic Review and Meta-Analyses. We searched MEDLINE, EMBASE, Cochrane, CINAHL and PSYCHINFO up to May 2023. We included cohort, case-control, and cross-sectional studies of any language. Pairs of reviewers independently screened studies, extracted data and assessed the risk of bias using the CLARITY tool and the Joanna Briggs Institute checklist. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. Where possible, we conducted random-effects meta-analyses to summarise our findings. RESULTS: We analysed 30 studies (>9000 participants) that assessed the association between acute postoperative pain and POD/POCD. Dose-response meta-analyses found that postoperative pain intensity was associated with occurrence of POD (adjusted relative risk [aRR]/unit of pain intensity: 1.26; 95% confidence interval [CI]: 1.17-1.35; low certainty of evidence) and risk of developing POD (aRR/unit of pain intensity: 1.18; 95% CI: 1.08-1.30; low certainty of evidence). There was very low certainty of evidence regarding the association between postoperative pain and POCD. No studies assessed the association between CPSP and POCD. Residual confounding and substantial methodological variability between studies prevented pooling data from many of the included studies and lowered certainty of evidence. CONCLUSIONS: Dose-response meta-analyses found that postoperative pain intensity was associated with occurrence of and risk of developing POD. SYSTEMATIC REVIEW PROTOCOL: PROSPERO-CRD42021192105.

Dietary total antioxidant capacity and risk of stroke: a systematic review and dose-response meta-analysis of observational studies.

Background: Previous studies have reported the association between dietary total antioxidant capacity (TAC) and risk of stroke, but these findings have been inconsistent. We therefore performed this systematic review and dose­response meta-analysis of observational studies to evaluate the association between dietary TAC and risk of stroke. Methods: A systematic literature search was carried out through PubMed, ISI Web of Science, EBSCO, Scopus and China National Knowledge Infrastructure (CNKI) databases, to find the relevant articles published up to 31 May, 2024. Random-effects or fixed-effects models were used to pool the relative risks (RRs) and their 95% confidence intervals (CIs) where appropriate. Heterogeneity across studies were determined using the Cochran's Q test and I-square (I 2) statistics. Results: Eight observational studies (six cohort and two case­control studies) were included in the final analysis. The pooled results showed that higher intake of dietary TAC was associated with a lower risk of stroke (RR = 0.88; 95%CI: 0.81­0.95, p = 0.002). Additionally, dose­response analysis of cohort studies demonstrated a linear association between dietary TAC intake and risk of stroke (RR = 0.994; 95%CI: 0.990­0.999, P non-linearity = 0.329, P dose­response = 0.014). Subgroup analyses showed the inverse association between dietary TAC intake and risk of stroke in the studies with mean age < 50 (RR = 0.82, 95%CI: 0.67­0.99, p = 0.044), and there was no evidence of heterogeneity (p = 0.360; I 2 = 0.0%). Conclusion: Our findings indicated that higher intake of dietary TAC was inversely associated with the risk of stroke. Future studies in particular of longitudinal design are needed to confirm this inverse relationship. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024547706.

Role of physical activity and sedentary behavior in venous thromboembolism: a systematic review and dose-response meta-analysis.

Increasing studies have investigated the link between physical activity (PA) and sedentary behavior with venous thromboembolism (VTE) but the existing findings are not consistent and the independent relationship is uncertain. This meta-analysis aimed to comprehensively assess the shape of dose-response relationship between PA and sedentary behavior with VTE and further explore whether the relationship is independent after mutual adjustment. We systematically searched PubMed, Embase and Web of Science from inception to August 1, 2024. PA exposures were converted into MET-h/wk. Categorical meta-analyses and a cubic spline model were performed to evaluate the association between PA, sedentary behavior and VTE. Twenty-five articles including 31 studies were included. A curvilinear dose-response relationship between PA and VTE was observed, with steeper gradients even at lower PA levels. After adjustment for sedentary behavior, higher level of PA was independently associated with a reduced VTE risk (OR = 0.83, 95%CI:0.77-0.89). Based on population attributable fraction analyses, 2.37% (95%CI: 1.90-2.85%) of incident VTE could have been prevented if all adults had achieved half the PA minimum recommended level. A linear dose-response relationship between sedentary behavior and VTE risk was found, and there was a 2% higher risk of VTE (OR = 1.02, 95%CI: 1.00-1.03) for 1 h increment of sedentary behavior per day. After adjustment for PA, sedentary behavior was independently associated with an increased VTE risk (OR = 1.19, 95CI%:1.01-1.39). Our analyses demonstrated PA and sedentary time were indeed independently associated with the risk of VTE after mutually adjusting for sedentary time or PA, highlighting a unique perspective on their individual contributions. Further studies assessing the effects of different combinations of PA and sedentary time for assessing joint effects on VTE are needed.

Cadmium exposure and risk of hypertension: a systematic review and dose-response meta-analysis.

BACKGROUND: Exposure to environmental toxic metals represents a significant global public health concern. Many studies have reported that cadmium (Cd) exposure increases the risk of hypertension. Since the shape of such relation has not been well characterized, we assessed it by performing a systematic review and dose-response meta-analysis of human studies. METHODS: We searched the literature through September 5, 2024 to identify papers related to Cd, hypertension, and blood pressure. Inclusion criteria were: observational design, adult population, assessment of exposure using Cd biomarkers, and availability of exposure category-specific risk estimates for hypertension. We performed a dose-response meta-analysis of the results from included studies. RESULTS: Of the 18 studies published between 2006-2024, most had a cross-sectional design. Cd was measured in whole blood and/or urine in almost all studies, whereas only two studies measured Cd in serum. The dose-response meta-analysis indicated an almost linear relation between urinary Cd concentrations and hypertension risk with RR=1.18, 95% CI 1.02-1.37 at 2.0 µg/g creatinine compared with no exposure. In contrast, the association between blood Cd concentrations and hypertension risk was non-linear: there was a steep monotonic increase in risk for Cd concentrations below 2 µg/L, reaching a RR of 1.48 (95% CI 1.17-1.86) at 2.0 µg/L, after which a plateau seemed reached. We found similar trends when restricting to studies of Asian population, while when considering North American studies, hypertension risk increased above 1.0 µg/g creatinine. CONCLUSIONS: In this dose-response meta-analysis, risk of hypertension showed a non-linear positive association with blood Cd concentrations and a linear positive association with urinary Cd concentrations. Inconsistency in the shape of associations could relate to the different timing of exposure assessed by the biomarkers or the alteration Cd excretion at increasing exposure levels. Mitigation of Cd exposure is confirmed as a public health priority for chronic disease prevention.

Aerobic exercise training and obstructive sleep apnea: dose-response meta-analyses.

PURPOSE: Several studies have shown that aerobic exercise training improves obstructive sleep apnea (OSA) severity. However, a dose-response relationship has never been shown. This study aimed to quantify any dose-response relationships between time spent per week in aerobic exercise and key sleep apnea outcomes. METHODS: Randomized controlled trials (RCT) were selected from literature search studying the effects of supervised aerobic exercise training on patients with OSA. Dose-response meta-analyses were performed, where the 'dose' was the total weekly duration of aerobic exercise training. Primary outcomes were apnea hypopnea index (AHI), cardiorespiratory fitness (maximum oxygen consumption or VO2peak) and Epworth Sleepiness Scale (ESS). RESULTS: Analysis of data from 11 RCTs showed a non-linear dose-response relationship between the total weekly duration of aerobic exercise training and mean differences in AHI. Maximum effects on AHI (-10.92 (95%CIs: -15.57; -6.27)) were observed when the weekly duration of aerobic exercise reached 100 min/week. Similar non-linear dose-response trend was observed in the mean differences in VO2peak. Studies in which aerobic exercise training lasted ≥ 12 weeks showed greater proportional changes in mean AHI differences with maximal effects reaching a peak at ∼ 70 min/week of aerobic exercise training. ESS and total weekly duration of aerobic exercise training showed a linear dose-response relationship based on 4 RCTs. CONCLUSIONS: Based on these analyses, aerobic exercise training of 70-100 min/week over 3 or 5 days a week should be recommended as adjunctive treatment for patients with OSA.

Association of dietary glycemic index and glycemic load with the risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis.

OBJECTIVE: To comprehensively assess the dose-response association between dietary glycemic index (GI) and glycemic load (GL) and gestational diabetes mellitus (GDM) risk. METHODS: PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang, and VIP databases were searched up to May 29, 2024. Studies with at least three exposure categories were included. Dose-response analysis was also performed when covariates were adjusted in the included studies. RESULTS: Thirteen studies involving 39,720 pregnant women were included. A linear relationship was found between GI and the risk of GDM (χ2 = 4.77, Pnon-linearity = .0923). However, association was not significant (χ2 = 0.06, p = .8000). For every unit increase in GI (range 0-30), GDM risk increased by 0.29%. After adjusting for covariates, the linear relationship persisted (χ2 = 4.95, Pnon-linearity = .084) with no significant association (χ2 = 0.08, p = .7775). For GL, a linear relationship was also found (χ2 = 4.17, Pnon-linearity =.1245), but GL was not significantly associated with GDM risk (χ2 = 2.63, p = .1049). The risk of GDM increased by 0.63% per unit increase in GL. After covariate adjustment, a significant association was observed (χ2 = 6.28, p = .0122). CONCLUSION: No significant association between GI and GDM risk was found. After adjusting for covariates, GL shows a significant association with GDM risk. Our findings emphasize the importance of considering dietary GL in managing the risk of GDM. Future research should continue to explore these relationships with standardized diagnostic criteria and robust adjustment for potential confounders.

The severity of intrahepatic cholestasis during pregnancy increases risks of adverse outcomes beyond stillbirth: evidence from 15,826 patients.

BACKGROUND: What kinds of fetal adverse outcomes beyond stillbirth directly correlate to the severity of intrahepatic cholestasis during pregnancy (ICP) remained tangled. Herein, we conducted a retrospective cohort study and a dose-response meta-analysis to speculate the association between the severity of ICP and its adverse outcomes. METHODS: We retrospectively collected a cohort of ICP patients from electronic records from Guangzhou Women and Children's Medical Center between Jan 1st, 2018, and Dec 31st, 2022. Also, we searched PubMed, Cochrane, Embase, Scopus, and Web of Science to extract prior studies for meta-analysis. The Kruskal-Wallis test, a one-way or two-way variants analysis (ANOVA), and multi-variant regression are utilized for cohort study. One stage model, restricted cubic spline analysis, and fixed-effect model are applied for dose-response meta-analysis. The data analysis was performed using the R programme. RESULTS: Our cohort included 1,289 pregnant individuals, including 385 mild ICP cases, 601 low moderate ICP cases, 282 high moderate ICP cases, and 21 severe ICP cases. The high moderate bile acid levels were correlated to preterm birth [RR = 2.14, 95%CI 1.27 to 3.62), P < 0.01], and preterm premature rupture of membranes [RR = 0.34, 95%CI 0.19 to 0.62), P < 0.01]. We added our cases to cases reported by other studies included in the meta-analysis. There were 15,826 patients included in dose-response meta-analysis. The severity of ICP was associated with increased risks of stillbirth, spontaneous preterm birth, iatrogenic preterm birth, preterm birth, admission to neonatal intensive care unit, and meconium-stained fluid (P < 0.05). CONCLUSIONS: Our study shows the correlation between the severity of ICP and the ascending risks of stillbirth, preterm birth, and meconium-stained fluid, providing new threshold TBA levels. PROSPERO REGISTRATION NUMBER: CRD42023472634.

Night shift work and female breast cancer: a two-stage dose-response meta-analysis for the correct risk definition.

INTRODUCTION: The hypothesis of this study is night shift work exposure can increase the risk of female breast cancer. To validate this hypothesis, the authors conducted a two-stage dose-response meta-analysis with improved quality on this topic. METHODS: The medical librarian searched PubMed, EMBASE, and the Cochrane Library on December 30th, 2022. The eight inclusion criteria were determined and strictly applied to the selection process. A reliable dose-response meta-analysis methodology was applied. RESULTS: Reliable 10 cohort (total cases: 15,953, and total person-years: 6,812,138) and 11 case-control reports (total cases: 9196, and total controls:12,210) were included in the final analysis. The pooled risk ratio (RR) of female breast cancer (from cohort studies) for 1, 10, 20, and 30 years of night shift work exposure was 1.0042 (95% CI 1.0014-1.0070), 1.0425 (95% CI 1.0138-1.0719), 1.0867 (95% CI 1.0278-1.1490), and 1.1328 (95% CI 1.0419-1.2317), respectively. The pooled odds ratio (OR) of female breast cancer (from case-control studies) for 1, 10, 20, and 30 years of night shift work exposure was 1.0213 (95% CI 1.0108-1.0319), 1.2346 (95% CI 1.1129-1.3695), 1.5242 (95% CI 1.2386-1.8756), and 1.8817 (95% CI 1.3784-2.5687), respectively. DISCUSSION: This study has several strengths from the perspective of a dose-response meta-analysis: Strictly applied eight inclusion criteria, separately synthesized RRs from cohort studies and ORs from case-control studies, clearly defined exposure dose, years of night shift work for each risk estimate, a reliable dose-response meta-analysis methodology, and careful considering of selection, exposure, and outcome biases and confounder adjustment for each study. This careful consideration of potential biases and confounding led to the exclusion of unreliable two cohort and five case-control studies.

Artificially sweetened beverage consumption and all-cause and cause-specific mortality: an updated systematic review and dose-response meta-analysis of prospective cohort studies.

BACKGROUND: Artificially sweetened beverages (ASB) are consumed globally, but their impact on overall health remains uncertain. We summarized published associations between ASB intake with all-cause and cause-specific mortality. METHODS: We searched Medline, Embase, Web of Science, and Cochrane CENTRAL databases until August 2023. Random effect meta-analysis was conducted to calculate pooled risk ratios (RRs) and 95% confidence intervals (95%CIs) for highest versus lowest categories of ASB consumption in relation to all-cause and cause-specific mortality. Linear and non-linear dose-response analyses were also performed. RESULTS: Our systematic review and meta-analysis included 11 prospective cohort studies. During a median/mean follow-up period of 7.0 to 28.9 years, 235,609 deaths occurred among 2,196,503 participants. Intake of ASB was associated with higher risk of all-cause and CVD mortality with pooled RRs (95%CIs) of highest vs. lowest intake categories of 1.13 (1.06, 1.21) (I2 = 66.3%) for all-cause mortality and 1.26 (1.10, 1.44) (I2 = 52.0%) for CVD mortality. Dose-response analysis revealed a non-linear association of ASB with all-cause mortality (pnon-linearity = 0.01), but a linear positive association with CVD mortality (pnon-linearity = 0.54). No significant association was observed for ASB intake and cancer mortality. Moreover, a secondary meta-analysis demonstrated that replacing 1 serving/day of sugary sweetened beverages (SSB) with ASB was associated with 4-6% lower risk of all-cause and CVD mortality. Per NutriGrade, the evidence quality for associations between ASB intake with all-cause and CVD mortality was moderate. CONCLUSIONS: Higher intake of ASB was associated with higher risk of all-cause and CVD mortality, albeit a lower risk than for SSB. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42022365701.

Response trajectory to left dorsolateral prefrontal rTMS in major depressive disorder: A systematic review and meta-analysis: Trajectory of rTMS.

The depression response trajectory after a course of repetitive transcranial magnetic stimulation(rTMS) remains understudied. We searched for blinded randomized controlled trials(RCTs) that examined conventional rTMS over left dorsolateral prefrontal cortex(DLPFC) for major depressive episodes(MDE). The effect size was calculated as the difference in depression improvement, between active and sham rTMS. We conducted a random-effects dose-response meta-analysis to model the response trajectory from the beginning of rTMS to the post-treatment follow-up phase. The area under curve (AUC) of the first 8-week response trajectory was calculated to compare antidepressant efficacy between different rTMS protocols. We included 40 RCTs(n = 2012). The best-fitting trajectory model exhibited a logarithmic curve(X2=17.7, P < 0.001), showing a gradual ascent with tapering off around the 3-4th week mark and maintaining until week 16. The maximum effect size was 6.1(95 %CI: 1.25-10.96) at week 16. The subgroup analyses showed distinct trajectories across different rTMS protocols. Besides, the comparisons of AUC showed that conventional rTMS protocols with more pulse/session group or more total pulses were associated with greater efficacy than those with fewer pulse/session or fewer total pulses, respectively. A course of conventional left DLPFC rTMS could lead to both acute antidepressant effects and sustained after-effects, which were modeled by different rTMS protocols in MDE.

Investigating the Relationship between Cadmium Exposure and the Risk of Prostate Cancer: A Systematic Review and Dose-Response Meta-Analysis.

Background: Cadmium, a toxic heavy metal, experienced a surge in production during the 20th century due to the rise of nickel-cadmium batteries, metal plating, and plastic stabilizers. Exposure to cadmium primarily occurs through the consumption of contaminated food, such as vegetables and grains, as well as drinking water or inhaling polluted air. The objective of this study was to investigate the relationship between cadmium exposure and the incidence of prostate cancer using a systematic review and meta-analysis approach. Methods: This research involved searching and retrieving observational and experimental studies conducted until May 2022 from various databases, including ISI Web of Science, Cochrane, Science Direct, Scopus, Pub-Med, and Google Scholar. Data analysis was performed using Stata 15 statistical software. Results: The initial search yielded 794 articles, which were subsequently reduced to 427 articles after eliminating duplicates. Following the application of inclusion and exclusion criteria, a total of 16 studies were included in the meta-analysis. The odds ratio of prostate cancer compared to the first quartile of exposure in the second quartile was 1.03 (0.95-1.12), in the third quartile it was 1.12 (0.99-1.26) and in the fourth quartile of exposure was equal to 1.16 (0.79-1.70). Regarding the investigation of the probability of the occurrence of publication bias, the results of Begg's and Egger's tests were not statistically significant. Conclusion: Although exposure to cadmium leads to an increase in the chance of prostate cancer, this chance increase was not statistically significant.

Association Between Vitamin D Level and Clinical Outcomes of Assisted Reproductive Treatment: A Systematic Review and Dose-Response Meta-Analysis.

The investigation about association between vitamin D level and clinical outcomes of assisted reproductive treatment showed various outcomes. This study aimed to review the correlation between vitamin D and outcomes of assisted reproductive treatment. The search was registered on the PROSPERO database (CRD42023458040). PubMed, Embase, Medline, ClinicalTrials.gov, and Cochrane databases were searched up to July 2023. Twenty-three observational studies were selected for meta-analysis. Comparing groups with deficient and 'insufficient + sufficient' vitamin D level, meta-analysis showed positive correlation between clinical pregnancy rate and vitamin D (OR 0.81, 95%CI: 0.70, 0.95, P = 0.0001). Comparing groups with 'deficient + insufficient' and sufficient vitamin D level, meta-analysis showed positive correlation between vitamin D and clinical pregnancy rate (OR 0.71, 95%CI: 0.55, 0.91, P = 0.006), vitamin D and live birth rate (OR 0.69, 95%CI: 0.54, 0.89, P = 0.003). Subgroup analysis did not show the source of high heterogeneity. No correlation was found in biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. In dose-response meta-analysis, a nonlinear association was found between vitamin D levels and outcomes when levels are below approximately 24 ng/L. The study shows that vitamin D level is associated with clinical pregnancy rate and live birth rate. Low vitamin D level does not influence biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. Furthermore, 24 ng/L may be a possible threshold of vitamin D concentration in assisted reproduction therapy.

The dose-effect relationship of six stimulation parameters with rTMS over left DLPFC on treatment-resistant depression: A systematic review and meta-analysis.

This study aimed to evaluate the association of the six parameters, namely stimulation intensity, stimulation frequency, pulses per session, treatment duration, number of sessions, and total number of pulses with the efficacy of conventional transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex for patients with treatment-resistant depression (TRD). A random-effects dose-response meta-analysis of blinded randomized controlled trials (RCTs) involving 2391 participants were conducted to examine the dose-effect relationship of six stimulation parameters. Any of the six parameters significantly individually predicted proportion of variance in efficacy: pulses per session (R²=52.7%), treatment duration (R²=51.2%), total sessions (R²=50.9%), frequency (R²=49.6%), total pulses (R²=49.5%), and intensity (R²= 40.4%). Besides, we identified frequency as a potential parameter interacting with the other five parameters, resulting in a significant increase in variance(ΔR2) ranging from 5.0% to 16.7%. Finally, we found that RCTs using frequency > 10 Hz compared to those of 10 Hz showed better dose-effect relationships. We conclude that the six stimulation parameters significantly predict the dose-effect relationship of conventional rTMS on TRD. Besides, higher stimulation frequency, higher stimulation intensity, and adequate number of pulses were associated with treatment efficacy.

The effects of citrus flavonoids supplementation on endothelial function: A systematic review and dose-response meta-analysis of randomized clinical trials.

The present systematic review and dose-response meta-analysis was conducted to synthesize existing data from randomized clinical trials (RCTs) concerning the impact of citrus flavonoids supplementation (CFS) on endothelial function. Relevant RCTs were identified through comprehensive searches of the PubMed, ISI Web of Science, and Scopus databases up to May 30, 2023. Weighted mean differences and their corresponding 95% confidence intervals (CI) were pooled utilizing a random-effects model. A total of eight eligible RCTs, comprising 596 participants, were included in the analysis. The pooled data demonstrated a statistically significant augmentation in flow-mediated vasodilation (FMD) (2.75%; 95% CI: 1.29, 4.20; I2 = 87.3%; p < 0.001) associated with CFS compared to the placebo group. Furthermore, the linear dose-response analysis indicated that each increment of 200 mg/d in CFS led to an increase of 1.09% in FMD (95% CI: 0.70, 1.48; I2 = 94.5%; p < 0.001). The findings from the nonlinear dose-response analysis also revealed a linear relationship between CFS and FMD (Pnon-linearity = 0.903, Pdose-response <0.001). Our findings suggest that CFS enhances endothelial function. However, more extensive RTCs encompassing longer intervention durations and different populations are warranted to establish more precise conclusions.

Pegbelfermin for reducing transaminase levels in patients with non-alcoholic steatohepatitis: a dose-response meta-analysis of randomized controlled trials.

Background: The efficacy of Pegbelfermin (PGBF) in treating non-alcoholic steatohepatitis (NASH) remains controversial. Therefore, we conducted a dose-response meta-analysis to explore the effect and pattern of PGBF at different dosages and treatment durations on transaminase reduction in NASH patients. Methods: We conducted searches on PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov, and supplemented the search with gray literature and manual searches. Randomized controlled trials (RCTs) evaluating the efficacy of PGBF in NASH patients were included. Risk of bias was assessed by Cochrane Risk of Bias Tool 2.0. We used random-effects models, generalized least squares regression, constrained maximum likelihood, and restricted cubic splines to explore the dose-response relationship. Egger's linear regression was employed to assess publication bias. The study is registered with PROSPERO, CRD42023448024. Results: Four RCT studies from the period 2018-2023, involving 546 participants, were included. No participants discontinued PGBF treatment due to adverse events. High-dose PGBF treatment significantly reduced transaminase levels in NASH patients compared to the low-dose group (ALT %: MD = 14.94, 95% CI = 2.11-27.77; AST %: MD = 9.05, 95% CI = 3.17-14.92). Longer treatment duration further decreased transaminase levels (ALT%: MD = 8.81, 95% CI = 4.07-13.56; AST%: MD = 6.72, 95% CI = 2.62-10.81). Egger's test did not reveal significant publication bias (p > 0.05). Further investigation indicated a ceiling effect of PGBF dosage on transaminase reduction at 30 mg/week, and NASH patients experienced a rebound in transaminase levels after 28 weeks of continuous treatment. Conclusion: There is a positive correlation between PGBF dosage and transaminase reduction within a certain range, showing an overall non-linear dose-response relationship. This finding provides guidance for the clinical application of PGBF. Clinicians should be mindful of the dosage ceiling at 30 mg/week and monitor changes in transaminase levels after 28 weeks for timely adjustments in PGBF dosage. Systematic review registration: PROSPERO, CRD42023448024. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=448024.

Dose-response curves: the next frontier in plant ecology.

A large fraction of experimental work in plant ecology, and thus also on ecosystem functioning and the delivery of ecosystem services, describes experiments that have been carried out under controlled (glasshouse) conditions. Controlled growth settings commonly sacrifice realism through, for example, reducing the densities of plant species in the pots and controlling how environmental settings such as moisture and light vary in favor of a higher mechanistic resolution, which makes these studies particularly suitable for subsequent syntheses. We explore the possibility that further integration of dose-response curves can maximize the impact of existing studies. We suggest that we can expand considerably the scope of the dose and response variables that are considered in plant ecology.

Risk of prostate cancer with increasing years of night shift work: A two-stage dose-response meta-analysis with duration of night shift work as exposure dose.

Introduction: Night shift work could be a modifiable risk factor for prostate cancer. However, the epidemiological evidence is inconsistent. To summarize the existing evidence on this topic, we conducted a two-stage dose-response meta-analysis. Methods: Medical librarians searched PubMed, EMBASE, and the Cochrane Library on December 30, 2022. Seven criteria were used to determine the inclusion of each study in the present analysis. Results: Eleven cohort studies (12 cohort reports; total cases: 9366; and total person-years: 88,238,009) and seven case-control studies (seven case-control reports; total cases: 5593; and total controls: 6876) were included. This study estimated that the risk of prostate cancer increased by 1, 12, 24, and 39% after 1, 10, 20, and 30 years of night shift work exposure, respectively, according to four cohort and five case-control studies. Discussion: Seven inclusion criteria were used to determine which studies were eligible for this analysis. Risk ratios from cohort studies and odds ratios from case-control studies were analyzed separately. However, all odds ratios from the case-control studies were excluded because of a high likelihood of publication bias. Moreover, exposure, measured in years of night shift work, was defined based on the information provided by individual studies. Finally, we utilized a recently reported two-stage dose-response meta-analysis method. This study provides evidence that night shift work contributes to the risk of prostate cancer in a dose-dependent manner.

Ultra-processed food consumption and chronic kidney disease risk: a systematic review and dose-response meta-analysis.

Background: High intake of ultra-processed food (UPF) has been associated with increased risk of chronic kidney disease(CKD), but the results remain inconsistent. We therefore performed this systematic review and dose­response meta-analysis of observational studies that shed light on the association between UPF consumption and the risk of CKD. Methods: A systematic literature search of PubMed, Embase, Web of Science, Scopus and China National Knowledge Infrastructure (CNKI) databases was carried out to find the eligible articles published up to October 31, 2023. Random-effects or fixed-effects models were used to pool the relative risks(RRs) and their 95% confidence intervals (CIs).The potential sources of heterogeneity across studies were examined using the Cochran's Q test and I-square(I2). Publication bias was examined using the visual inspection of asymmetry in funnel plots and quantified by Begg's and Egger's tests. Results: Eight studies (six cohort and two cross-sectional studies) exploring the association between UPF consumption and risk of CKD, were included in the final analysis. The pooled analyses revealed that high consumption of UPF was associated with an increased risk of CKD (RR = 1.25; 95%CI: 1.09­1.42, p < 0.0001). Moreover, a 10% increase of UPF consumption was associated with a 7% higher risk of CKD (RR = 1.07; 95%CI: 1.04­1.10, p < 0.001). Dose­response analysis of all included studies showed a linear association between UPF consumption and the risk of CKD (RR = 1.02; 95%CI:0.99­1.05, Pdose­response = 0.178, Pnonlinearity = 0.843). Conclusion: Our findings indicate that high consumption of UPF is significantly associated with an increased risk of CKD. Future research with prospective design is required to confirm this positive association.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023478483, PROSPERO identifier CRD42023478483.

The influence of n-3 polyunsaturated fatty acids on cognitive function in individuals without dementia: a systematic review and dose-response meta-analysis.

BACKGROUND: Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been suggested as a cognitive enhancing agent, though their effect is doubtful. We aimed to examine the effect of n-3 PUFA on the cognitive function of middle-aged or older adults without dementia. METHODS: We reviewed randomized controlled trials of individuals aged 40 years or older. We systematically searched PubMed/MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Library databases. We used the restricted cubic splines model for non-linear dose-response meta-analysis in terms of the standardized mean difference with 95% confidence intervals. RESULTS: The current meta-analysis on 24 studies (n 9660; follow-up 3 to 36 months) found that the beneficial effect on executive function demonstrates an upward trend within the initial 12 months of intervention. This effect is prominently observed with a daily intake surpassing 500 mg of n-3 PUFA and up to 420 mg of eicosapentaenoic acid (EPA). Furthermore, these trends exhibit heightened significance in regions where the levels of blood docosahexaenoic acid (DHA) + EPA are not very low. CONCLUSIONS: Supplementation of n-3 PUFA may confer potential benefits to executive function among the middle-aged and elderly demographic, particularly in individuals whose dietary DHA + EPA level is not substantially diminished.