The role of vitamin D in outcomes of critical care in COVID-19 patients: Evidence from an umbrella meta-analysis of interventional and observational studies

OBJECTIVES

Several meta-analyses have suggested the beneficial effect of vitamin D on patients infected with SARS-CoV-2. This umbrella meta-analysis aims to evaluate influence of vitamin D supplementation on clinical outcomes and the mortality rate of COVID-19 patients.

DESIGN

Present study was designed as an umbrella meta-analysis. The following international databases were systematically searched till March 2023: Web of Science, PubMed, Scopus, and Embase.

SETTINGS

Random-effects model was employed to perform meta-analysis. Using AMSTAR critical evaluation tools, the methodological quality of the included meta-analyses was evaluated.

PARTICIPANTS

Adult patients suffering from COVID-19 were studied.

RESULTS

Overall, 13 meta-analyses summarizing data from 4 RCTs and 9 observational studies were identified in this umbrella review. Our findings revealed that vitamin D supplementation and status significantly reduced mortality of COVID-19 [Interventional studies: (ES= 0.42; 95% CI: 0.10, 0.75, p <0.001; I2 = 20.4%, p=0.285) and observational studies (ES= 1.99; 95% CI: 1.37, 2.62, p <0.001; I2 = 00.0%, p=0.944). Also, vitamin D deficiency increased risk of infection and disease severity among patients.

CONCLUSION

Overall, vitamin D status is a critical factor influencing the mortality rate, disease severity, admission to ICU and being detached from mechanical ventilation. It is vital to monitor the vitamin D status in all patients with critical conditions including COVID patients.

The efficacy of curcumin in relieving osteoarthritis: A meta-analysis of meta-analyses

Osteoarthritis (OA) is one of the most prevalent degenerative joint diseases. Several meta-analyses have shown that curcumin could improve the function of the knee and alleviate pain in OA, while some meta-analyses demonstrate controversial results. Hence, we assessed curcumin's effects on knee OA in an umbrella meta-analysis. PubMed, Scopus, Embase, and Web of Science databases were employed to find English-language meta-analyses of randomized controlled trials investigating the effect of curcumin supplementation on OA outcomes up to September 2023. The visual analog scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, function, and stiffness scales were analyzed. Effect sizes and 95% confidence intervals were utilized to obtain the overall effect size. A random-effects model was applied to perform the meta-analysis. Heterogeneity was determined by I2 statistics and the Cochrane Q-test. The pooled effect of the 11 included meta-analyses showed that curcumin could significantly decrease the VAS score (weighted mean difference [WMD] and standardized mean difference [SMD]), WOMAC-total (SMD and WMD), WOMAC-Function (SMD and WMD), WOMAC-Pain (SMD), and WOMAC-Stiffness scores (SMD) (p ≤ 0.001, ≤0.001, ≤0.001, 0.007, ≤0.001, 0.002, ≤0.001, ≤0.001, respectively). The results strongly support curcuminoid supplementation in relieving pain, improving joint mobility and stiffness, and shortening medication usage of OA patients.

Corrigendum: Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis

[This corrects the article DOI: 10.3389/fnut.2023.1117387.].

The Effect of Vitamin D Supplementation on Lipid Profiles: an Umbrella Review of Meta-Analyses

According to published meta-analyses, vitamin D exerts different beneficial effects in preventing and controlling risk factors associated with noncommunicable chronic diseases; however, the results are still conflicting. The purpose of this umbrella meta-analysis was to investigate the effect of vitamin D supplementation on low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol (TC), and triglyceride (TG) as components of the lipid profile. PubMed, Scopus, Web of Science, and Cochrane Database of Systematic Reviews were systematically searched for meta-analyses of randomized controlled trials. The umbrella meta-analysis followed the PRISMA guidelines. The random-effects model was employed to estimate the overall effect size (ES). Overall, 25 meta-analyses were included. In the standardized mean difference analysis, vitamin D significantly decreased TG (ES: -0.15; 95% CI: -0.23, -0.08; P ≤ 0.001) and TC levels (ES: -0.17; 95% CI: -0.23, -0.11; P ≤ 0.001) and increased HDL levels (ES: 0.08; 95% CI: 0.01, 0.15; P = 0.025). In the weighted mean difference analysis, vitamin D significantly decreased only TG levels (ES: -4.63 mg/dL; 95% CI: -7.70, -1.57; P = 0.003). The present study supports that vitamin D supplementation could be considered a beneficial adjuvant therapy in managing lipid profile levels, especially in individuals with vitamin D deficiency. This systematic review was registered in PROSPERO as CRD42022306334.

The Impact of Vitamin D Supplementation on Improving Blood Pressure: Evidence Obtained From an Umbrella Meta-analysis

PURPOSE

The results of meta-analyses regarding the effect of vitamin D on blood pressure are conflicting. The present umbrella meta-analysis was conducted to provide definite and conclusive results.

METHODS

Systematically, Scopus, EMBASE, PubMed, and Web of Science databases and Google Scholar were searched for relevant literature published up to July 2022. All meta-analyses of clinical trials addressing the effect of vitamin D on blood pressure were included. Random effects analysis was performed to obtain the overall effect size based on the standardized mean differences (SMDs) and weighted mean differences (WMDs) separately. The quality of included meta-analyses was assessed by using the Measurement Tool for Assessing Multiple Systematic Reviews 2 questionnaire.

FINDINGS

Overall, 21 meta-analyses were enrolled in the umbrella review. The results indicated that systolic blood pressure was significantly reduced after the intervention based on WMD effect size analysis (ESWMD = -0.69 mm Hg; 95% CI, -1.35 to -0.04 [P < 0.038]; I2 = 46.7%, P = 0.021); however, no considerable impact was observed based on analysis of SMD effect sizes (ESSMD = -0.05 mm Hg; 95% CI, -0.24 to 0.14; P = 0.615). Also, vitamin D supplementation indicated a significant improvement in diastolic blood pressure based on WMD effect sizes (ESWMD = -0.66 mm Hg; 95% CI, -1.05 to -0.27 [P < 0.001]; I2 = 56.4%, P = 0.004) but not SMD analysis (ESSMD = -0.04 mm Hg; 95% CI, -0.13 to 0.04 [P = 0.328]; I2 = 53.4%, P = 0.057).

IMPLICATIONS

Based on obtained evidence, vitamin D could be considered an efficient adjuvant for improving blood pressure.

Can omega-3 fatty acids and vitamin E co-supplementation affect obesity indices?

Background: Studies have shown that vitamin E as an antioxidant protects omega-3 fatty acids (FAs) from oxidation. Several studies have evaluated the effect of omega-3 FAs and vitamin E co-supplementation on obesity indices; however, the results are inconsistent. The present systematic review and meta-analysis was conducted to address the role of omega-3 FAs plus vitamin E on obesity indices. Methods: Cochrane Library, PubMed, Scopus, Embase, and Web of Science databases were searched up to February 2022. Among all of the qualified studies, 10 articles were selected. The effect size was presented as weighted mean difference (WMD) and 95% confidence interval (CI). Fixed-effects model was employed to perform meta-analysis. Subgroup analysis and publication bias assessment were carried out. Results: Ten eligible randomized controlled trials comprising 558 participants were included. The average dose of omega-3 FAs and vitamin E co-supplementation in studies was 1000-4000 mg/day and 400 IU, respectively. Intervention duration varied from 6 to 16 weeks. There was no significant effect of omega-3 and vitamin E co-supplementation on body weight (BW) (WMD=0.14 kg; 95% CI: -0.13 to 0.42; p=0.297), and body mass index (BMI) (WMD=0.08, 95% CI: -0.01 to 0.16, p=0.073). However, subgroup analysis showed that it might increase BMI in women over 50 years and if the intervention lasted more than 8 weeks. Conclusion: There was no significant impact of combined omega-3 FAs and vitamin E supplementation on BW and BMI; however, it should be noted that the intervention has an increasing impact when supplementation duration was >8 weeks and in individuals with type 2 diabetes mellitus, >50 years old, and BMI>25 kg/m2.

The effect of propolis supplementation in improving antioxidant status: A systematic review and meta-analysis of controlled clinical trials

The present study aimed to assess the effect of propolis supplementation on oxidative status, a key contributor to the etiology of many chronic diseases. A systematic search of multiple databases, including Web of Science, SCOPUS, Embase, PubMed, and Google Scholar, was conducted from inception to October 2022 to identify articles examining the effect of propolis on glutathione (GSH), glutathione peroxidase (GPX), total antioxidant capacity (TAC), superoxide dismutase (SOD), and malondialdehyde (MDA) levels. The quality of the included studies was evaluated using the Cochrane Collaboration tool. A total of nine studies were included in the final analysis, and a random-effects model was used to pool the estimated effects. Results showed that propolis supplementation significantly increased the levels of GSH (SMD = 3.16; 95% CI: 1.15, 5.18; I2  = 97.2%), GPX (SMD = 0.56; 95% CI: 0.07, 1.05; p = 0.025; I2  = 62.3%), and TAC (SMD = 3.26; 95% CI: 0.89, 5.62; I2  = 97.8%, p < 0.001). However, the effect of propolis on SOD was not significant (SMD = 0.05; 95% CI: -0.25, 0.34; I2  = 0.0%). Although the MDA concentration was not significantly decreased overall (SMD = -0.85, 95% CI: -1.70, 0.09; I2  = 93.3%), a significant decrease in MDA levels was observed at doses ≥1000 mg/day (SMD = -1.90; 95% CI: -2.97, -0.82; I2  = 86.4) and supplementation durations of less than 11 weeks (SMD = -1.56; 95% CI: -2.60, -0.51; I2  = 90.4). These results suggest that propolis is a safe supplement with a beneficial effect on GSH, GPX, and TAC levels and may be an effective adjunctive therapy for diseases where oxidative stress is a key factor in the etiology. However, further high-quality studies are necessary to make more precise and comprehensive recommendations given the limited number of studies, clinical diversity, and other limitations.

The effectiveness of treatment with probiotics in Helicobacter pylori eradication: results from an umbrella meta-analysis on meta-analyses of randomized controlled trials

Background and aims: The purpose of this umbrella meta-analysis was to quantitatively summarize meta-analyses of randomized controlled trial (RCT) studies regarding the effects of probiotic supplementation on Helicobacter pylori (H. pylori) eradication. Methods: A thorough search of the electronic databases including PubMed, Web of Science, Embase, Scopus, and Google Scholar was carried out from the inception up to May 2022. For the evaluation of overall effect sizes, the pooled relative risk (RR) or odds ratio (OR) and their corresponding 95% confidence intervals (CI) were calculated. The random-effects model was used for the meta-analysis. Results: Overall, 18 eligible studies (47 278 participants in total) were included in the study. The findings revealed that probiotics have a beneficial impact on H. pylori eradication (pooled ESRR: 1.13; 95% CI: 1.11, 1.14, p < 0.01, and ESOR = 1.86, 95% CI: 1.70, 2.03, p < 0.01). Greater effects on H. pylori eradication were observed when higher doses (>10 × 1010 CFU) and mixed strains were supplemented. Conclusion: The present umbrella meta-analysis suggests that supplementation with probiotics may be considered as an efficient approach to ameliorate H. pylori complications, particularly probiotics with higher CFUs and mixed strains.

Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis

Introduction

Numerous meta-analyses have demonstrated the beneficial effects of probiotics on oxidative stress biomarkers, although some studies have contradictory results. Therefore, the current research was conducted to obtain a precise and definite understanding on the impact of probiotics on oxidative stress biomarkers in adults.

Methods

We conducted a comprehensive systematic search of results on Scopus, PubMed, Embase, Web of Science, and Google Scholar dating up to March 2022. Fifteen meta-analyses were included in this umbrella meta-analysis. The random-effects model was employed to obtain the overall effect size. Subgroup analyses were carried out based on supplementation dosage and duration, mean age, and study population.

Results

Our results indicated that probiotics supplementation meaningfully decreased serum malondialdehyde (MDA) (ESWMD = -0.56, 95% CI: -0.72, -0.39; p < 0.001, and ESSMD = -0.50, 95% CI: -0.66, -0.34; p < 0.001). Moreover, the findings showed that probiotics resulted in a significant increase in total antioxidant capacity (TAC) (ESWMD = 29.18, 95% CI: 16.31, 42.04; p < 0.001, and ESSMD = 0.25, 95% CI: 0.02, 0.47; p = 0.032), total glutathione (GSH) (ESWMD: 30.65; 95% CI: 16.94, 44.35, p < 0.001), and nitric oxide (NO) (ESWMD: 1.48; 95% CI: 0.31, 2.65, p = 0.013; I2 = 51.7%, p = 0.043).

Discussion

Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.

Dietary pattern in autism increases the need for probiotic supplementation: A comprehensive narrative and systematic review on oxidative stress hypothesis

Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut microbiota. Autistic patients have an elevated abundance of certain gut bacteria associated with increased oxidative stress in the gastrointestinal tract. Probiotic supplementation has been shown to decrease oxidative stress in a simulated gut model, but the antioxidant effects of probiotics on the oxidative stress of the gut in autistic patients have not been directly studied. However, it is speculated that probiotic supplementation may help decrease oxidative stress in the gastrointestinal tract of autistic patients due to their specific dietary habits altering the microbiota. PubMed, Scopus and Web of Science databases and Google Scholar were searched up to May 2023. This systematic-narrative review aims to present the latest evidence regarding the changes in eating habits of autistic children which may further increase the gut microbiota induced oxidative stress. Additionally, this review will assess the available literature on the effects of probiotic supplementation on oxidative stress parameters.

The effect of cinnamon supplementation on glycemic control in patients with type 2 diabetes or with polycystic ovary syndrome: an umbrella meta-analysis on interventional meta-analyses

BACKGROUND

Several meta-analyses reported glycemic-lowering effects of cinnamon, while others reported conflicting findings. In the present study, we aimed to perform an umbrella meta-analysis of previous interventional meta-analyses on the effects of cinnamon on glycemic control in patients with type 2 diabetes (T2D) or with polycystic ovary syndrome (PCOS).

METHODS

Relevant studies were searched in PubMed, Scopus, EMBASE, Web of Science, and Google Scholar up to June 2022. Meta-analyses of randomized clinical trials (RCTs) investigating the effects of cinnamon on glycemic indices including fasting plasma glucose (FPG), homeostatic model assessment for insulin resistance (HOMA-IR), insulin, and hemoglobin A1C (HbA1c) were included. Random-effects models were used to perform the umbrella meta-analysis and pool the weighted mean difference (WMD) or standardized mean difference (SMD) and their 95% confidence intervals (CI).

RESULTS

Overall, 11 meta-analyses of RCTs were included. Cinnamon supplementation was effective in reducing serum FPG (WMD: -10.93 mg/dL; 95%CI: -16.22, -5.65; SMD: -0.86; 95%CI: -1.19, -0.52), insulin (WMD: -2.01 IU/mL; 95%CI: -3.96, -0.07; SMD: -0.61; 95%CI: -0.93, -0.30), HOMA-IR levels (WMD: -0.61; 95%CI: -0.91, -0.31; SMD: -0.78; 95%CI: -1.26, -0.30), and HbA1c (WMD: -0.10%; 95%CI: -0.17, -0.03).

CONCLUSION

Cinnamon can be used as an anti-diabetic agent and an add-on treatment to control glycemic indices among patients with T2D or PCOS.

N-acetylecysteine, a powerful agent in the reinforcement of anti-oxidant profile: A systematic review and dose-response meta-analysis of controlled clinical trials

BACKGROUND AND AIM

Several studies have been conducted to evaluate the effect of N-acetylecysteine (NAC) supplementation on antioxidant status, while no dose-response meta-analysis summarized the efficacy of NAC supplementation.

METHODS

The systematic search of literatures was conducted on Scopus, PubMed, Embase, Web of Science electronic databases. Controlled clinical trials investigating the effects of NAC on antioxidant biomarkers were included in the current meta-analysis. Random-effect model was used to perform meta-analysis. Heterogeneity was examined using I² index. Subgroup analysis was carried out to find the possible sources of heterogeneity. Dose-response analysis was performed to find the non-linear relationships between effect size and independent variables.

RESULTS

Overall, 26 eligible studies were included in the review. NAC supplementation significantly increased TAC (SMD = 0.77 μmol/L; 95% CI: 0.38, 1.16; p < 0.001), GSH (SMD = 0.80 nmol/ml; 95% CI:0.25, 1.34; p = 0.004) and CAT (SMD = -0.57 IU/L; 95% CI:-1.13, -0.02; p = 0.042) levels. However, no significant improving effect was observed in terms of GR (SMD = 0.25 IU/g; 95% CI:-0.14, 0.63; p = 0.210), SOD (SMD = 0.14 U/ml; 95% CI:-0.20, 0.49; p = 0.414) and GPx (SMD = 0.19 IU/g; 95% CI:-0.48, 0.86; p = 0.576) levels. Furthermore, dose-response analysis show that NAC supplementation in participants with mean age up to 30 years had more robust effect on increasing GSH levels.

CONCLUSION

We found a significant effect of NAC supplementation on TAC, GSH, CAT in adults. Overall, NAC could be considered as a potent agent in enhancing antioxidant capacity.

Effect of omega-3 supplementation on lipid profile in children and adolescents: a systematic review and meta-analysis of randomized clinical trials

PURPOSE

Dyslipidemia is considered as a known risk factor for cardiovascular disease. Yet various trials with wide ranges of doses and durations have reported contradictory results. We undertook this meta-analysis of randomized controlled trials (RCTs) to determine whether omega-3 supplementation can affect lipid profile in children and adolescents.

METHODS

Cochrane Library, Embase, PubMed, and Scopus databases were searched up to March 2021. Meta-analysis was performed using random-effect method. Effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was assessed using the I² index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta-regression analysis was conducted.

RESULTS

A total of 14 RCTs with 15 data sets were included. Based on the combination of effect sizes, there was a significant reduction in TG levels (WMD: -15.71 mg/dl, 95% CI: -25.76 to -5.65, P=0.002), with remarkable heterogeneity (I²=88.3%, P<0.001). However, subgroup analysis revealed that omega-3 supplementation significantly decreased TG only in studies conducted on participants ≤13 years old (WMD=-25.09, 95% CI: -43.29 to -6.90, P=0.007), (I²=84.6%, P<0.001) and those with hypertriglyceridemia (WMD=-28.26, 95% CI: -39.12 to -17.41, P<0.001), (I²=0.0%, P=0.934). Omega-3 supplementation had no significant effect on total cholesterol, HDL, and LDL levels. Also, results of nonlinear analysis showed significant effect of treatment duration on HDL status (P_{non-linearity}=0.047).

CONCLUSION

Omega-3 supplementation may significantly reduce TG levels in younger children and those with hypertriglyceridemia. Also, based on the HDL-related results, clinical trials with longer duration of intervention are recommended in this population.

Effects of probiotics supplementation on blood pressure: An umbrella meta-analysis of randomized controlled trials

AIMS

Several meta-analyses have revealed that probiotics could lower blood pressure (BP), but the findings were inconsistent. In this regard, an umbrella meta-analysis was carried out to provide a more accurate estimate of the overall impacts of probiotics supplementation on BP.

DATA SYNTHESIS

We searched the following international databases till November 2021: PubMed, Scopus, EMBASE, Web of Science, and Google Scholar. A random-effects model was applied to evaluate the effects of probiotics on BP. Sensitivity analysis was performed by using the leave-one-out method. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the certainty of evidence. Pooled effect size of 14 meta-analyses with 15,494 participants indicated significant decreases in both systolic (Weighted mean difference (WMD) = -1.96 mmHg; 95% confidence interval (CI): -2.78, -1.14, p < 0.001, and standardized mean difference (SMD) = -2.62; 95% CI: -4.96, -0.28, p < 0.001) and diastolic BP (WMD = -1.28 mmHg; 95% CI: -1.76, -0.79, p < 0.001, and SMD = -0.60 mmHg; 95% CI: -1.08, -0.12, p = 0.014) following probiotics supplementation. Greater effects on SBP were revealed in trials with a mean age of >50 years and the duration of intervention ≤10 weeks. DBP was also more reduced in studies with a dosage of ≥10¹⁰ colony forming unit (CFU), and SBP was decreased in patients with hypertension or diabetes analyzing WMD.

CONCLUSION

The present umbrella meta-analysis suggests probiotics supplementation to improve BP and claims that probiotics could be used as a complementary therapy for controlling high BP.

PROSPERO ID

CRD42022306560.

Vitamin D protects against depression: Evidence from an umbrella meta-analysis on interventional and observational meta-analyses

Meta-analyses of interventional and observational studies investigating the efficacy and the relationship between vitamin D and depression provided inconsistent results. The current umbrella meta-analysis was conducted to assess the available evidence and provide a conclusive outcome in this regard. The following international databases were systematically searched till March 2022: PubMed, Scopus, Embase, Web of Science, and Google Scholar. Random-effects model was carried out to calculate the pooled point estimates and their respective 95 % confidence intervals (CI). Ten meta-analyses of randomised controlled trials (RCTs) revealed significant reduction in depression symptoms comparing participants on vitmain D supplements to those on placebo (Pooled standardised mean difference: - 0.40; 95 % CI: - 0.60, - 0.21, p < 0.01: I² = 89.1 %, p < 0.01). Four meta-analyses of cohort studies (with one having two subgroups) revealed that participants with lower levels of serum vitamin D were at increased odds of depression than those with higher levels of serum vitamin D (Pooled odds ratio: 1.60; 95 % CI: 1.08, 2.36, p < 0.01; I² = 91.3 %, p < 0.01). The present umbrella meta-analysis confirms the potential benefits of vitamin D supplementation and higher serum vitamin D levels in reducing the development and symptoms of depression.

Effects of fenugreek supplementation on the components of metabolic syndrome: A systematic review and dose-response meta-analysis of randomized clinical trials

Metabolic syndrome (MetS) is a cluster of metabolic disorders with a heavy disease burden. Fenugreek was reported to be effective in some components of MetS. Therefore, a comprehensive review and meta-analysis of randomized controlled trials was conducted to study the effects of fenugreek on MetS indices. From the beginning until August 2022, PubMed, Embase, Scopus, and Web of science were searched. Data were analyzed using the random-effect model, and presented as weighted mean difference (WMD) and associated 95 % confidence interval (CI). This meta-analysis comprised from a total of 29 eligible RCTs with 31 arms measuring fasting plasma glucose (FPG), Triglyceride (TG), high-density lipoprotein (HDL), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP). The results indicated significant improving effects of fenugreek on FPG (WMD: -16.75 mg/dL; 95 % CI: -23.36, -10.15; P < 0.001), TG (-20.12 mg/dL; 95 % CI: -34.238, -5.994; P < 0.001), HDL (WMD: 3.55 mg/dL; 95 % CI: 1.98, 5.12; P < 0.001), WC (WMD: -2.51; 95 % CI: -3.78, -1.24; P < 0.001) and SBP (WMD: -3.45 mmHg; 95 % CI: -6.38, -0.52; P = 0.021); However the effect on DBP (WMD: 3.17; 95 % CI: -5.40, 11.73; P = 0.469) and BMI (WMD: -0.40 kg/m2; 95 % CI: -1.114, 0.324; P = 0.281) was not significant. Administration of fenugreek can meaningfully reduce FPG, TG, WC, and SBP and increase HDL. The overall results support possible protective and therapeutic effects of fenugreek on MetS parameters.

Effects of Probiotics Supplementation on CRP, IL-6, and Length of ICU Stay in Traumatic Brain Injuries and Multiple Trauma Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

METHOD

This meta-analysis aims to evaluate the effectiveness of probiotics in reducing inflammatory biomarkers and the length of intensive care unit (ICU) stays. PubMed-Medline, SCOPUS, Embase, and Google Scholar databases up to July 2021 were searched. The meta-analysis was carried out using random-effect analysis. To determine the sources of heterogeneity, subgroup analyses were performed. In case of the presence of publication bias, trim and fill analysis was carried out. The Cochrane Collaboration tool was used for checking the quality assessment. We hypothesized that probiotics would improve inflammatory markers (CRP and IL-6) and the length of ICU stay in traumatic brain injury and multiple trauma patients.

RESULTS

The present meta-analysis, which includes a total of seven studies, showed that there were no significant effects of probiotics supplementation on interleukin (IL)-6 (Hedges's g = -2.46 pg/ml; 95% CI: -12.16, 7.25; P=0.39), C-reactive protein (CRP) (Hedges's g = -1.10 mg/L; 95% CI: -2.27, 0.06; P=0.06), and the length of staying in ICU. The overall number of RCTs included in the analysis and the total sample size were insufficient to make firm conclusions.

CONCLUSION

As a result, more carefully designed RCTs are needed to investigate the effect of probiotics on inflammatory biomarkers and the length of ICU stay in traumatic brain injuries and multiple trauma patients in greater detail.

The influence of β-alanine supplementation on recovery biomarkers in adults: A systematic review and meta-analysis

Background: Clinical studies, investigating the effect of β-Alanine (BA) supplementation on recovery biomarkers in physically active individuals, have generated inconsistent results. This systematic review and meta-analysis study aimed to clarify the clinically relevant dietary effects of BA supplementation. Methods: A comprehensive search was done in the electronic databases of Scopus, PubMed, ISI Web of Science and Embase from inception to 2020. Meta-analysis was done using the random-effects model. Pooled effect size was evaluated using standard mean difference (SMD) and 95% confidence intervals (CI). Heterogeneity of between-study was evaluated according to Cochran’s Q test and I2. Subgroup analysis was conducted to identify the potential sources of heterogeneity. Results: Overall, 32 studies were included in the current study. The results suggested that BA supplementation increases carnosine level significantly (SMD: 0.22mmol/L, 95%CI: -0.17,0.61, P=0.27) but no effect was shown about lactate, fatigue, VO2, PH and bicarbonate (HCO3-) (P>0.05). Subgroup analysis revealed a significant association of VO2, carnosine and fatigue with supplementation dosage, gender and duration of administration respectively. Conclusion: BA supplementation emerged its beneficial effects on enhancing carnosine level which highlights its ergogenic effects. In contrast, no significant effects had been shown in term of fatigue delay and blood levels of lactate, HCO3-, PH, and VO2 value. These results warrant more investigation in a prospective design to clarify the exact mechanism in this way.

Are levels of adipokines and micronutrients different in male adult smokers and non-smokers? A case-control study

OBJECTIVE

Smoking is a common public problem leading to increases in oxidative stress and decreases in the levels of some micronutrients, finally affecting adipokine levels. The aim of this study was to compare the serum levels of omentin (intelectin-1), chemerin, TNF-α, and some micronutrient intakes in male smokers and non-smokers.

METHODS

40 male smokers and 40 male non-smokers with a mean age of 38.6±14.1 years were included in this study. Serum levels of omentin, chemerin, and TNF-α were measured. To calculate the daily intake of energy, carbohydrate, protein, fat, and some of the micronutrients, the 24-h recall and semi-quantitative food frequency questionnaire (FFQ) was used.

RESULTS

Omentin, chemerin, and TNF-α levels in male smokers were lower than non-smokers, but these differences were not statistically significant. However, after adjustment for total and saturated fat intakes and age, omentin (β=138.4, p=0.027) and TNF-α (β=144.5, p=0.015) revealed significant differences.

CONCLUSION

The serum levels of omentin, chemerin, TNF-α, and some micronutrient intakes were not significantly different between smokers and non-smokers. Further population studies are needed to clarify this subject.

Vitamin D supplementation positively affects anthropometric indices: Evidence obtained from an umbrella meta-analysis

Despite the growing evidence from meta-analyses on vitamin D’s anti-obesity properties, their results are controversial. The current umbrella review was performed to assess the available evidence and provide a conclusive explanation in this regard. The international databases PubMed, Scopus, Embase, Web of Science and Google Scholar were systematically searched till March, 2022. A random-effects model was used to run the meta-analysis. All meta-analyses that examined the effect of vitamin D supplementation on BW, BMI, WC, and fat mass were included. Findings of 14 meta-analyses revealed that vitamin D supplementation reduced body mass index (BMI) (ES: −0.11 kg/m²; 95% CI: −0.18, −0.05, p?0.001; I² = 61.0%, p < 0.001), and waist circumference (WC) (ES = −0.79 cm; 95% CI: −1.20, −0.37; p < 0.001; I² = 46.5%, p = 0.096) in comparison to control group. However, the effects of vitamin D on body weight (ES = −0.16 kg, 95% CI: −0.36, 0.04; p = 0.125; I² = 57.0%, p = 0.017), and fat mass (ES: 0.02, 95% CI: −0.20, 0.24, p = 0.868; I² = 0.0%, p = 0.531) were not considerable. Vitamin D supplementation significantly improved levels of obesity indices such as BMI, and WC.

Probiotic therapy, a novel and efficient adjuvant approach to improve glycemic status: An umbrella meta-analysis

BACKGROUND

Probiotics exert several promoting effects on the glycemic status, however, the results of meta-analyses are inconsistent. we conducted an umbrella meta-analysis, across existing systematic reviews and meta-analyses of clinical trials to determine the definite effects of supplementation with probiotics on glycemic indices.

METHODS

A comprehensive systematic search of PubMed/Medline, Scopus, EMBASE, and Web of Science was carried out till August 2021. The random-effects model was employed to conduct meta-analysis. Meta-analysis studies of randomized clinical trials examining the impacts of probiotics supplementation on glycemic indices were qualified in the current umbrella meta-analysis.

RESULTS

48 articles out of 693 in the literature search qualified for inclusion in the umbrella meta-analysis. Pooled effects of probiotics on fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), and insulin levels were reported in articles 45, 21, 35, and 33, respectively. The analysis indicated a significant decrease of FPG (ES= -0.51 mg/dL; 95% CI: -0.63, -0.38, p < 0.001), HbA1c (ES = -0.32 mg/dL; 95% CI: -0.44, -0.20, p < 0.001), HOMA-IR (ES= -0.56; 95% CI: -0.66, -0.47, p < 0.001), and insulin levels (ES= -1.09 IU/mL; 95% CI: -1.37, -0.81, p = 0.006) by probiotics supplementation.

CONCLUSION

Probiotics have amending effects on FPG, HbA1c, HOMA-IR, and insulin levels. A < 8-week period of probiotic supplementation in the moderate dosages (10⁸ or 10⁹ CFU) is an efficacious approach in improving glycemic parameters. Overall, probiotics could be recommended as an adjuvant anti-hyperglycemic agent.

Boron compound administration; A novel agent in weight management: A systematic review and meta- analysis of animal studies

BACKGROUND

The worldwide growing trend of obesity across all ages has increased the number of researches on the obesity management and prevention. Boron is a potential essential trace element and there are some promising results on its weight lowering effect. Therefore, the present meta-analysis was aimed to assess the effect of boron on body weight.

METHOD

Databases including PubMed, Scopus, Cochrane Library, Embase, and Google Scholar were searched from 1995 until November 2021 using the definitive keywords. Searching was limited to articles with English language. Human studies were excluded in our analyses regarding their limited number and the heterogeneity of study designs. All of the relevant animal studies on rodents with weight changes as a primary outcome were included. The assessments of risk of bias and heterogeneity were conducted using the Cochrane Risk of Bias tool and I-square (I2) statistic respectively.

RESULTS

According to our findings the overall effect of boron administration orally was significant decrease of body weight (WMD = -18.12 g 95% CI -23.28, -12.96; P < 0.001). The boron compound administration was more effective in the borax form and also when the intervention duration was ≤ 4 weeks. Moreover, the effect size was greater in the male gender rather than female animals.

CONCLUSION

Most of the experimental studies supported the weight lowering effect of boron although, there are a few inconsistent evidences. It seems that the weight lowering effect of boron may be through increasing the energy metabolism, thermogenesis, lipolysis and inhibition of adiposeness. However, future clinical trials can better clarify the effects of boron on obesity management.

Evaluation and prioritization of occupational safety and health risks of Shahid Sadoughi Hospital in Yazd in 2019

Introduction: Today, it is essential to pay attention to the opportunities and threats in health services, especially in hospitals, to identify and evaluate the existing risks and manage them in these centers. Hospital risk management is a program to reduce the occurrence and prevalence of preventable accidents and is of great economic, human and moral importance in the hospital environment. This study aimed to evaluate and prioritize the occupational safety and health risks of the staff of Shahid Sadoughi Hospital in Yazd in 2019  Methods and material: : The present study is descriptive-cross-sectional. In the first step, the main risks in clinical, laboratory, facilities, radiology, and administrative departments were identified. Based on FMEA logic, three severity, probability, and vulnerability indicators were identified for each risk. Then, prioritization criteria were determined, and ANP prioritized the risks. Results: According to infectious disease experts with a risk of 0.86 in the clinical ward, inhalation of Barisek chemical vapor 1.17 in the laboratory, radiation of the device with a risk of 0.64 in imaging, infectious disease with a risk of 0.33 and 1.3 in order of priority The first were in the administrative and facilities department. Conclusion: The  results showed that the hospital  management should adopt special management  programs to control infectious diseases with a staff  health approach. Control  measures should be set with priority risks. The difference in the obtained  risk numbers  indicated the different  priorities of implementing risk management  programs in each  ward of  Shahid  Sadoughi Hospital.

Probiotics, a Novel and Efficient Adjuvant Therapy in Improving Glycemic Status: An Umbrella Meta-Analysis

Objectives

Probiotics exert several promoting effects on the glycemic status, however, the results of meta-analyses are inconsistent. As a result, this paper conducted an umbrella meta-analysis, across existing systematic reviews and meta-analyses of clinical trials to determine the definite effects of supplementation with probiotics on glycemic indices

Methods

Meta-analysis studies of randomized clinical trials examining the impacts of probiotics supplementation on glycemic indices were qualified in the current umbrella meta-analysis. A comprehensive systematic search of PubMed/Medline, Scopus, EMBASE, and Web of Science was carried out till August 2021. Effect sizes (ES) and corresponding confidence intervals (CIs) were employed to obtain the overall effect sizes. I² statistics and Cochrane's Q-test was used to detect the heterogeneity. The random-effects model was employed to conduct meta-analysis.

Results

48 articles out of 693 in the literature search qualified for inclusion in the umbrella meta-analysis. Pooled effects of probiotics on fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), and insulin levels were reported in 45, 21, 35, and 33 articles, respectively. The analysis indicated a significant decrease of FPG (ES = −0.51 mg/dL; 95% CI: −0.63, −0.38, p < 0.001), HbA1c (ES = −0.32 mg/dL; 95% CI: −0.44, −0.20, p < 0.001), HOMA-IR (ES = −0.56; 95% CI: −0.66, −0.47, p < 0.001), and insulin levels (ES = −1.09 IU/mL; 95% CI: −1.37, −0.81, p = 0.006) by probiotics supplementation.

Conclusions

Probiotics have amending effects on FPG, HbA1c, HOMA-IR, and insulin levels. A < 8-week period of probiotic supplementation in the moderate dosages (10⁸ or 10⁹ CFU) is an efficacious approach in improving glycemic parameters. Overall, probiotics could be recommended as an adjuvant anti-hyperglycemic agent.

Funding Sources

None.

Inositol supplementation and body mass index: A systematic review and meta‐analysis of randomized clinical trials

Background

Inositol is a sugar‐alcohol and recognized as a key component of cell membrane phospholipids. It has crucial role in the cell signaling pathways and contribute to improving glycemic responses. Although some earlier studies have revealed the effect of inositol mediating glucose uptake by improving insulin sensitivity, the benefit of inositol supplementation in patients with overweight and obesity is not completely understood. This study aimed to assess the impact of inositol supplementation on body mass index (BMI) through a systematic review and meta‐analysis of controlled clinical trials.

Methods

A systematic search was performed to August 2021 in the following databases: PubMed‐Medline, Embase, Web of Science and Scopus. Fifteen controlled clinical trials investigating the effect of inositol on adult's BMI were finally included in the study. A random‐effects model was employed to estimate the effect size. Subgroup analysis was performed by dose, duration, age, type of inositol. Meta‐regression was used to investigate presence of any linear relationship. Begg's and Egger's tests were carried out to detect small study effect.

Results

The results of pooled analysis showed that inositol supplementation significantly decreased BMI scores (WMD = −0.41 kg/m²; 95% CI: −0.78, −0.04; p = 0.028). Subgroup analysis was performed to identify the source of heterogeneity among studies (I² = 73.9%, p < 0.001), demonstrating supplementation duration, baseline BMI, mean age of participants, type of inositol and dosage were potential sources of heterogeneity. The effect of intervention was more clinically significant in participants with polycystic ovary syndrome (PCOS) and overweight/obesity. Inositol in the form of myo‐inositol (MI) had stronger effect on BMI reduction.

Conclusion

The meta‐analysis suggests that oral inositol supplementation has positive effect on BMI reduction. Inositol supplementation could be considered as an adjunct treatment to improve body mass index.

Effective indicators of hospital resilience in epidemic conditions

Introduction: The concept of hospital resilience means "the ability of a hospital to withstand, absorb and respond to catastrophic shocks ."Humans have been plagued by a variety of disasters throughout their lives, including emerging diseases, and have suffered irreparable loss. Hospitals play a key role in crisis management and control of epidemics, and therefore the hospitals readiness to continue medical services in crises is of particular importance. Therefore, the present study was conducted with the aim of obtaining effective indicators on hospital resilience in epidemic conditions. Materials and Methods: A qualitative study was conducted to identify the indicators. The main method of data collection was semi-structured interviews with experts and also review of extensive texts. Finally, using qualitative content analysis method and with the help of MAXQDA software, the main dimensions, indicators and below Indicators were extracted. Results: According to the results, the main dimensions included: 3 dimensions (management and leadership, readiness and adaptability capacity ) and the main indicators include 11 indicators (manpower management, support services management, disease management, cohesion and structuring, redundancy, knowledge management, Organizational culture, service delivery, infection prevention and control, environmental health, recovery). The number of sub-main indicators is also 43. Conclusion: In order to improve resilience, hospitals can focus on the identified indicators and monitor and improve them. Correction and improvement of effective indicators will lead to the promotion of resilience and effective management and control of pandemic crises in hospitals.

Cinnamon, an effective anti-obesity agent: Evidence from an umbrella meta-analysis

The evidence provided by meta-analyses on the beneficial impacts of cinnamon supplementation on anthropometric indices are still conflicting. Present study's aim was to evaluate the effects of cinnamon on obesity indices by an umbrella meta-analysis. The electronic databases including Web of Science, PubMed, EMBASE, Scopus were systematically searched up to March 2021. Data for the effects of cinnamon on anthropometric indices were collected from the meta-analyses. An umbrella meta-analysis was carried out using a random-effects model. The pooled effects of 7 meta-analyses showed that cinnamon supplementation significantly reduced body weight (ES: -0.67 kg; 95% CI: -0.99, -0.35, p ˂ .001), body mass index (ES: -0.45 kg/m² ; 95% CI: -0.57, -0.33, p ˂ .001) in comparison to control group. However, the effects of cinnamon on waist circumference (ES: -1.05 cm; 95% CI: -2.26, 0.15, p = .087) were not considerable. According to results, cinnamon could be suggested as a complementary weight loss agent. Favorable results were obtained at a dose of ≥3 g/day. In this study, a comprehensive study was performed on meta-analyses performed on the effect of cinnamon on anthropometric indices. This study could be considered as a final conclusion about the effect of cinnamon on anthropometric indices. The results of this study showed that supplementation with cinnamon significantly reduces BMI and body weight. The impacts were greater in doses of ≥3 g/day and in PCOS patients. PRACTICAL APPLICATIONS: In this study, a comprehensive study was performed on meta-analyses performed on the effect of cinnamon on anthropometric indices. This study could be considered as a final conclusion about the effect of cinnamon on anthropometric indices. The results of this study showed that supplementation with cinnamon significantly reduces BMI and body weight. The impacts were greater in doses of ≥3 g/day and in PCOS patients.

Probiotics as an effective therapeutic approach in alleviating depression symptoms: an umbrella meta-analysis

Growing evidence has suggested that the consumption of probiotics can decrease depressive symptoms. However, even the results of meta-analyses are conflicting. In this regard, we performed an umbrella meta-analysis and proposed the decisive impacts of probiotics on depressive symptoms. The following international databases were searched up to July 2021: PubMed/Medline, Web of Science, Scopus, EMBASE, and Google Scholar. Meta-analyses investigating the impact of supplementation of probiotics on depression symptoms in adults were included. According to the studies, random-effects model was used to perform the analysis. Subgroup analysis was performed by dosage of probiotics, duration of supplementation and total sample size. Publication bias was assessed using Egger's, Begg's and visual inspection of funnel plot. Ten meta-analyses (n = 8886 participants) were included in study. The pooled data indicated that probiotic supplementation significantly reduced depression symptoms (ES= -1.41; 95% CI: -2.53, -0.30, p = 0.016; I2 = 99.4, p = <0.001). Subgroup analysis of studies with intervention duration >8 weeks and dosage >10 × 109 CFU demonstrated a more robust effect of probiotics on decreasing depression symptoms. There was also significant between-study heterogeneity in which dosage was identified as source of it. The results of present umbrella meta-analysis suggest administration of probiotics for relieving depression symptoms for >8 weeks with dosage of >10 × 109 CFU.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2051164.

The effects of N-acetylcysteine on recovery biomarkers: A systematic review and meta-analysis of controlled trials

N-acetylcysteine (NAC) is one of the antioxidant supplements which is thought to improve recovery. Existing studies regarding NAC and recovery presented conflicting results. This systematic review and meta-analysis evaluated the existing trials and determined the efficacy of acute and chronic NAC administration on recovery biomarkers. PubMed, Web of Science, and Scopus were searched up to July 2021. The random effects or fixed effects model was applied in the meta-analysis. Sensitivity and subgroup analyses were performed. In case of the presence of publication bias, standard methods were applied. The meta-analysis comprised 37 papers (1,388 participants). All included studies were in English language. Acute NAC administration indicated no significant effects on lactate, pH, VO₂ , and CPK-MB ([SMD = -0.06 mmol/L; 95% CI: -0.40, 0.28; p = .714], [SMD = 0.17; 95% CI: -0.28, 0.62; p = .454], [SMD = -0.11 L/min; 95% CI: -0.63, 0.41; p = .686], and [SMD = -0.19 units/L; 95% CI: -0.62, 0.24; p = .395]). Additionally, no evidence of significant influence of chronic NAC administration on lactate, pH, VO₂ , and CK was revealed ([SMD = 0.01 mmol/L; 95% CI: -0.25, 0.27; p = .950], [SMD = -0.51; 95% CI: -1.73, 0.70; p = .424], [SMD = -0.18 L/min; 95% CI: -0.56, 0.20; p = .361], and [SMD = -0.04 units/L; 95% CI: -0.36, 0.29; p = .821]). No considerable effect of NAC on recovery was found. PRACTICAL APPLICATIONS: Previous studies on the influence of NAC administration on recovery biomarkers have presented conflicting results. This systematic review and meta-analysis offers a broad range of detailed information on the influence of chronic and acute NAC supplementation outcomes regarding recovery biomarkers. Overall, the results support that NAC supplementation may not be effective in improving recovery biomarkers. However, subgroup analyses based on NAC dosage indicated the meaningful effect of NAC on CK-MB at the dosage of ≥100 mg/kg.

The effects of all trans retinoic acid, vitamin D3 and their combination on plasma levels of miRNA-125a-5p, miRNA-34a, and miRNA-126 in an experimental model of diabetes

OBJECTIVE

The purpose of this study was to evaluate the effects of ATRA (all trans retinoic acid), vitamin D3, and their combination on circulating levels of miR (MicroRNA) -125a-5p, miR-126, and miR-34ain diabetic rats.

MATERIALS AND METHODS

Total miRNA was extracted from plasma samples. miRNA expression profiles of 30 rats in five groups were analyzed after 4-week intervention. The expression levels of miRNAs were measured using qRT-PCR.

RESULTS

We analyzed the expression of miR-126, miR-125a-5p, and miR-34a in serum among all five groups (p=0.268). The levels of miRNA-126 (p=0.004) and miR-125a-5p (p=0.014) showed a significant difference among our experimental groups. The circulating levels of miR-126 decreased in DC (Diabetic control) group compared to the HC (Healthy control) group (p=0.009). In addition, vitamin D3+ATRA supplementation increased miR-126 expression (p=0.014). Moreover, the levels of miR-125a-5p decreased in the DC group compared to the HC group (p=0.019).

CONCLUSION

The expression of miR-126 and miR-125a-5p decreased in diabetic rats. Also, vitamin D3+ATRA can be considered a new therapeutic agent that can elevate miR-126 expression and prevent diabetes-related cardiovascular complications.

A systematic review and meta-analysis on the impact of oral vitamin E supplementation on apolipoproteins A1 and B100

BACKGROUND AND AIM

Cardiovascular diseases (CVDs) are the number one cause of mortality worldwide. Apolipoprotein B (ApoB), apolipoprotein A1 (ApoA1), and ApoB/ApoA1 ratio are considered as predictors of CVD alongside with lipid profile. Evidence suggest that nutrients with antioxidant properties, especially vitamin E, are essential for a healthy cardiovascular system. The aim of present meta-analysis was to determine the effect alpha-tocopherol on ApoA1 and ApoB levels.

METHODS

PubMed-Medline and SCOPUS databases and Google Scholar were searched up to July 2021. Random-effects model was employed to perform meta-analysis. In order to find heterogeneity sources, subgroup analysis was performed. Trim and fill analysis was performed in case of presence of publication bias. Quality assessment was performed using Cochrane Collaboration's tool.

RESULTS

Seven eligible studies, involving 1284 individuals were included. Mean age of participants ranged between 25.4 and 59 years. There was no significant effect of vitamin E supplementation on Apo A1 (SMD = 0.22 IU/d; 95% CI: -0.38, 0.28; P = 0.481) and Apo B levels (SMD = -0.62 IU/d; 95% CI: -1.94, 0.70; P = 0.360).

CONCLUSION

No remarkable effect of vitamin E supplementation was observed on ApoA1 and ApoB levels in adults. Additional studies investigating the influence of vitamin E on apolipoproteins as primary outcome with larger sample size are suggested.

Investigation of the clinical efficacy of Zn supplementation in improvement of oxidative stress parameters: A systematic review and dose-response meta-analysis of controlled clinical trials

BACKGROUND/OBJECTIVES

Clinical efficacy of zinc (Zn) supplementation in the improvement of oxidative stress biomarkers has been investigated in some clinical trial studies. The purpose of the current dose-response meta-analysis is to systematically aggregate and evaluate all related studies to highlight the possible effect of Zn supplementation on oxidative stress.

METHODS

Systematic search was performed on Scopus, PubMed/Medline, Web of Science and Embase up to 31 December 2020. The random effect method was used to perform pooled analysis. Possible sources of heterogeneity were found using subgroup analysis and meta-regression. In the presence of publication bias, trim and fill analysis was performed to adjust the results. Non-linear relationship between effect size and variables was investigated by performing dose-response analysis. The quality of included studies was assessed using Cochrane Collaboration's tool.

RESULTS

Pooled-analysis of 18 studies showed that Zn supplementation improved MDA and Hcys levels (SMD = -1.53 μmol/L; 95% CI: -2.22, -0.85; P < .001 and SMD = -0.62 μmol/L; 95% CI: -1.08, -0.15; P < .001, respectively). There was no significant effect of Zn supplementation on TBARS (SMD = -0.59 μmol/l; 95% CI: -1.31, 0.13; P = .108). Zn had maximum reducing effect on MDA in <40 mg/day dosage.

CONCLUSION

Zn supplementation reduces MDA and Hcys levels, but not TBARS level. Supplementation with Zn <40 mg/day has an optimum effect on MDA level. Zn supplementation could be considered clinically as a beneficial approach in amending oxidative stress.

Probiotics act as a potent intervention in improving lipid profile: An umbrella systematic review and meta-analysis

Several meta-analysis studies have revealed improving effects of probiotics on lipid profile, while some studies have reported controversial findings. The purpose of present study was to evaluate the efficacy of probiotics on blood lipids. Relevant studies were searched in the international databases, including PubMed, Scopus, EMBASE, Web of Science, and Cochrane Central Library up to August 2021. The pooled results were calculated with the use of a random-effects model to assess the effects of probiotics on blood lipids. Overall, 38 meta-analyses were inclueded in the study. The results indicated that the probiotics supplementation was effective on reduction of total cholesterol (TC) (ES= -0.46 mg/dL; 95% CI: -0.61, -0.30, p < 0.001; I²= 83.8%, p < 0.001), triglycerides (TG) (ES= -0.13 mg/dl; 95% CI: -0.23, -0.04, p = 0.006; I²= 74.7%, p < 0.001), and low-density lipoprotein cholesterol (LDL-C)levels (ES= -0.29 mg/dL; 95% CI: -0.40, -0.19, p < 0.001; I²= 77.8%, p < 0.001). There was no significant effect of probiotics on high-density lipoprotein cholesterol (HDL-C) levels (ES= 0.02 mg/dl; 95% CI: -0.04, 0.08, p = 0.519; I²= 72.5%, p= <0.001). The results of present umbrella meta-analysis strongly support supplementation with probiotics as an influential intervention for improving lipid profile.

Saffron, as an adjunct therapy, contributes to relieve depression symptoms: An umbrella meta-analysis

BACKGROUND

Saffron is a traditional herbal medicine that has been used to treat various ailments such as depressive mood. However, the findings of several meta-analyses regarding anti-depressive properties of saffron (Crocus sativus L.) are controversial. The current umbrella meta-analysis was carried out to determine the magnitude and direction of saffron administration on depression.

METHODS

Relevant studies were searched in international databases including PubMed, Scopus, EMBASE, Web of Science, and Cochrane Central Library up to June 2021. Meta-analysis studies investigating the effects of saffron on depression were considered to include in the study. Random-effects model was used to perform the meta-analysis. Additional analyses including subgroup and sensitivity analyses were carried out.

RESULTS

Overall, 7 meta-analyses were included in the study. The results demonstrated that the consumption of saffron resulted in a significant reduction in BDI scores (ES: -3.87; 95% CI: -5.27, -2.46). However, saffron did not change the HAMD scores (ES: -2.10; 95% CI: -5.05, 0.86, p = 0.164) and mixed scores (HAM-D/BDI/DASS) (ES: 0.02; 95% CI: -0.39, 0.43,p = 0.941).

CONCLUSION

Present umbrella meta-analysis demonstrated that saffron intake might contribute to alleviation of depression disorder, however, it cannot be considered as a single therapeutic approach to treat depression.

Effects of vitamin D supplementation on apolipoprotein A1 and B100 levels in adults: Systematic review and meta-analysis of controlled clinical trials

Cardiovascular disease (CVD) is a leading cause of death around the world. According to the studies, apolipoproteins A1 and B100 play crucial role in CVD development and progression. Also, findings have indicated the positive role of vitamin D on these factors. Thus, we conducted the present meta-analysis of randomized controlled trials (RCTs) to demonstrate the impact of vitamin D supplementation on apolipoproteins A1 and B100 levels in adults. PubMed and Scopus databases and Google Scholar were searched up to 21 December 2020. Relevant articles were screened, extracted, and assessed for quality based on the Cochrane collaboration's risk of bias tool. Data analysis conducted by random-effect model and expressed by standardized mean difference (SMD). The heterogeneity between studies was assessed by I-squared (I2) test. Subgroups and sensitivity Analyses were also conducted. Seven RCTs were identified investigating the impact of vitamin D on Apo A1 levels and six on Apo B100 levels. The findings showed the insignificant effect of vitamin D supplementation on Apo A1 (SMD=0.26 mg/dL; 95% confidence interval (CI), -0.10, 0.61; P = 0.155) and Apo B100 (standardized mean difference (SMD)=-0.06 mg/dL; 95% CI, -0.24, 0.12; P = 0.530) in adults. There was a significant between-study heterogeneity in Apo A1 (I2=89.3%, P < 0.001) and Apo B100 (I2 = 57.1%, P = 0.030). However, significant increase in Apo A1 in daily dosage of vitamin D (SMD=0.56 mg/dL; 95% CI, 0.02, 1.11; P = 0.044) and ≤12 weeks of supplementation duration (SMD=0.71 mg/dL; 95% CI, 0.08, 1.34; P = 0.028) was observed. No significant effects of vitamin D on Apo A1 and Apo B100 levels after subgroup analysis by mean age, gender, study population, dosage and duration of study. Overall, daily vitamin D supplementation and ≤12 weeks of supplementation might have beneficial effects in increasing Apo A1 levels, however, future high-quality trials considering these a primary outcome are required.

Spirulina supplementation as an adjuvant therapy in enhancement of antioxidant capacity: A systematic review and meta-analysis of controlled clinical trials

BACKGROUND

Spirulina, a type of blue-green algae, is used as an adjuvant treatment of metabolic and inflammatory diseases. Evidence about the effects of spirulina on antioxidant system are conflicting. Thus, this quantitative review aimed to summarise the effects of spirulina administration on antioxidant status biomarkers.

METHODS

Systematic searches were conducted using the PubMed/Medline, Scopus, Web of Science and EMBASE, up to May 2021. Random effect analysis was applied to perform meta-analysis. Subgroup analyses and multivariate meta-regression were performed to find heterogeneity sources. Quality assessment was conducted using Cochrane Collaboration's tool. Trim and fill analysis were also carried out in case of the presence of publication bias.

RESULTS

A total of nine articles that enrolled 415 subjects were included in the present meta-analysis. Obtained findings exhibited that spirulina supplementation had marginal significant effect on total antioxidant capacity (TAC) (SMD = 0.49; 95% CI: -0.001, 0.98; P = .05) and superoxide dismutase (SOD) activity (SMD = 0.72; 95% CI: -0.03, 1.46; P = .06), while did not affect glutathione peroxidase (GPx) activity (SMD=0.27; 95% CI: -0.23, 0.77; P = .29).

CONCLUSIONS

Spirulina consumption may exert beneficial effects on enhancement of antioxidant system. A marginal significant increasing effect on TAC and SOD activity were found by spirulina administration. However, it did not affect GPx activity.

Clinical efficacy of zinc supplementation in improving antioxidant defense system: A comprehensive systematic review and time-response meta-analysis of controlled clinical trials

Oxidative stress is a contributing factor to many chronic diseases. It has been investigated that zinc (Zn) may enhance the antioxidant defense. The current dose-response and time-response meta-analysis aims to determine the efficacy of Zn supplementation in improving antioxidant defense. Scopus, PubMed/Medline, Web of Science, and Embase databases were searched systematically up to December 30, 2020. Meta-analysis was performed on human controlled clinical trials using random effects method. To find any source of heterogeneity, subgroup analysis and meta-regression were performed. Trim and fill analysis was used for adjusting the publication bias. To find any non-linear relationship between variables and effect size, dose-response and time-response analyses were performed. Cochrane Collaboration's tool was used for evaluating the quality assessment. A total of 23 controlled clinical trials were analyzed. The range of Zn supplementation duration in various studies was within 4-24 weeks. Zn supplementation did not have beneficial effects on glutathione peroxidase (GPx) activity (SMD = -0.34 U/g; 95% CI: -0.93, 0.25; P = 0.258). There were significant increasing effects of Zn supplementation on glutathione (GSH) (SMD = 1.28 μmol/l; 95% CI: 0.42, 2.14; P = 0.003) and total antioxidant capacity (TAC) levels (SMD = 1.39 mmol/l; 95% CI: 0.44, 2.35; P = 0.004). Zn had ameliorative effects on superoxide dismutase (SOD) activity after elimination of publication bias (SMD: 0.84 U/g; 95% CI: 0.12, 1.56, P < 0.05). Zn could also elevate GSH and TAC levels, plus SOD activity after modifying the publication bias. Finally, Zn had no significant effect on GPx activity.

Spirulina supplementation and oxidative stress and pro-inflammatory biomarkers: A systematic review and meta-analysis of controlled clinical trials

Studies investigating the effects of spirulina on inflammation and oxidative stress status are controversial. Therefore, the current systematic review and meta-analysis aimed to evaluate the impacts of spirulina supplementation on oxidative stress indicators and inflammatory markers. PubMed-Medline, SCOPUS, Web of Science, Embase databases and Google Scholar were searched up to 1 October 2020. Random-effect analysis was applied to perform meta-analysis. Subgroup analyses and multivariate meta-regression were performed to find heterogeneity sources. Quality assessment was conducted using Cochrane Collaboration's tool. A total of 11 studies that enrolled 465 subjects were included in our meta-analysis. Pooled results demonstrated a significant increase in interleukin-2 (IL-2) concentrations [Standardized mean difference (SMD = 2.69 pg/mL; 95% CI: 0.26, 5.11; P = .03)]; however this result changed to insignificant (SMD = 0.54 pg/mL; 95% CI: -1.29, 2.27; P > .05) when sensitivity analysis performed. A marginal decreasing effect were also found on interleukin-6 (IL-6) (SMD = -0.72 mg/dL; 95% CI: -1.50, 0.07; P = .073) and thiobarbituric acid reactive substances (TBARS) levels (SMD = -0.65; 95% CI: -1.37, 0.08; P = .08). In addition, results of subgroup analysis revealed a significant reduction in IL-6 and TBARS concentrations when the baseline body mass index (BMI) of participants was lower than 25 kg/m2 . Moreover, spirulina had no significant effect on tumour necrosis factor-α (TNF-α) (SMD = -0.07 mg/dL; 95% CI: -0.33, 0.18; P = .56) and malondialdehyde (MDA) concentrations (SMD = -0.42; 95% CI: -0.98, 0.14; P = .14). Spirulina consumption contributed to a significant increase in IL-2 concentrations changing to insignificant after sensitivity analysis and marginal decreasing effects on IL-6 and TBARS levels. No considerable impacts were observed on TNF-α and MDA concentrations.

Changes in plasma phospholipids and sphingomyelins with aging in men and women: A comprehensive systematic review of longitudinal cohort studies

BACKGROUND

Aging affects the serum levels of various metabolites which may be involved in the pathogenesis of chronic diseases. The aim of this review article is to summarize the relationship between aging and alterations in the plasma phospholipids and sphingomyelins.

METHODS

PRISMA guidelines were employed during all steps. MEDLINE (PubMed), Scopus, Embase and Web of Sciences databases and Google Scholar were searched up to October 2020. Cohort studies investigating the relationship between aging and within-person changes in sphingomyelin (SM), phosphatidyl choline (PC), lyso PC (LPC) and phosphatidyl ethanolamine (PE) were included. Newcastle-Ottawa scale was used to assess the quality of included studies.

RESULTS

A total of 1425 studies were identified. After removing 610 duplicates and 723 irrelevant studies, full texts of 92 articles were evaluated. Of these 92, 6 studies (including data from 7 independent cohorts) met the inclusion criteria and are included in this review. All study populations were healthy and included both men and women. Results by sex were reported in 3 cohorts for PC, 5 cohorts for LPC, 3 cohorts for SM, and only 1 cohort for PE. In men, PC, SM, PE and LPC decreased with aging, although results for LPC were inconsistent. In women, LPC, SM, and PE increased age, whereas changes in PC were inconsistent.

CONCLUSION

Within-person serum levels of phospholipids and sphingomyelins, decrease during aging in men and increase in women. Notably, however, there were some inconsistencies across studies of LPC in men and of PC in women.

Effect of bariatric surgery on endogenous sex hormones and sex hormone-binding globulin levels: a systematic review and meta-analysis

BACKGROUND

Most studies have shown beneficial effect of bariatric surgery (BS) on serum levels of sex hormones.

OBJECTIVE

A systematic review and meta-analysis was conducted to examine the magnitude of possible changes in levels of sex hormones following BS.

SETTINGS

Electronic databases were searched, including PubMed, Scopus, Web of Science, and Embase, for relevant studies.

METHODS

The heterogeneity of the studies was examined by χ² tests and the degree of heterogeneity was estimated using I² statistic.

RESULTS

The results of pooled analyses revealed that BS caused a significant increase in luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), and sex hormone binding globulin (SHBG) levels and conversely, decreased dehydroepiandrosterone (DHEA) and estradiol (E2) levels in males. For females, BS significantly increased LH, FSH, and SHBG levels and conversely, decreased androstenedione (AE), E2 and TT levels. Additionally, the level of progesterone (P), prolactin (PRL), free testosterone (FT) and dehydroepiandrosterone sulfate (DHEA-S) showed no significant changes in patients who had undergone BS.

CONCLUSION

BS changed most sex hormones levels including LH, FSH, TT, SHBG, AE, DHEA, and E2. It seems that BS is able to exert substantial impacts on sex hormones levels and as well as sexual function, however, larger, and more precise trials are required to specifically focus on these claims.

Can vitamin E supplementation affect obesity indices? A systematic review and meta-analysis of twenty-four randomized controlled trials

BACKGROUND

Several mechanisms have been proposed for the effect of vitamin E on weight loss. Yet various interventional studies with wide ranges of doses and durations have reported contradictory results.

METHODS

Cochrane Library, PubMed, Scopus, and Embase databases were searched up to December 2020. Meta-analysis was performed using random-effect method. Effect size was presented as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was evaluated using the I² index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta regression analyses was conducted.

RESULTS

A total of 24 studies with 33 data sets were included. There was no significant effect of vitamin E on weight (WMD: 0.15, 95% CI: -1.35 to 1.65, P = 0.847), body mass index (BMI) (WMD = 0.04, 95% CI: -0.29 to 0.37, P = 0.815), and waist circumference (WC) (WMD = -0.19 kg, 95% CI: -2.06 to 1.68, P = 0.842), respectively. However, subgroup analysis revealed that vitamin E supplementation in studies conducted on participants with normal BMI (18.5-24.9) had increasing impact on BMI (P = 0.047).

CONCLUSION

There was no significant effect of vitamin E supplementation on weight, BMI and WC. However, vitamin E supplementation might be associated with increasing BMI in people with normal BMI (18.5-24.9).

The Relationship Between Vitamin D and Telomere/Telomerase: A Comprehensive Review

Telomeres are repetitive nucleotide sequences that together with the associated sheltrin complex protect the ends of chromosomes and maintain genomic stability. Evidences from various organisms suggests that several factors influence telomere length regulation, such as telomere binding proteins, telomere capping proteins, telomerase, and DNA replication enzymes. Recent studies suggest that micronutrients, such as vitamin D, folate and vitamin B12, are involved in telomere biology and cellular aging. In particular, vitamin D is important for a range of vital cellular processes including cellular differentiation, proliferation and apoptosis. As a result of the multiple functions of vitamin D it has been speculated that vitamin D might play a role in telomere biology and genomic stability. In this study, our main goal is investigating the relationship between telomerase enzyme and vitamin D. Findings of this study suggest that higher vitamin D concentrations, which are easily modifiable through nutritional supplementation, are associated with longer LTL, which underscores the potentially beneficial effects of this hormone on aging and age-related diseases. Vitamin D may reduce telomere shortening through anti-inflammatory and anti-cell proliferation mechanisms. Significant Low levels of telomerase activity create short telomeres, which in turn signal exit from the cell cycle resulting in cell senescence and apoptosis. In follow-up examination, the patients who remained vitamin D deficient tended to have shorter telomeres than those patients whose 25-hydroxyvitamin D levels were depleted. Increasing 25-hydroxyvitamin D levels in patients with SLE may be beneficial in maintaining telomere length and preventing cellular aging. Moreover, anti-telomere antibody levels may be a promising biomarker of SLE status and disease activity.