Health risk assessment of heavy metal pollutants in Iranian hen eggs: a systematic review and meta-analysis.

Eggs are a high-quality, nutrient-dense source of protein that is available at a relatively low price and the contamination of eggs by heavy metals is an important issue in public health. This review aimed to assess the risk of heavy metal pollutants in Iranian hen eggs. Original full-text available studies in Iran, detecting levels of Pb, Cd, As, and Hg in whole or part of the egg, and published between January 2000 and March 2023 were selected based on the inclusion criteria. The random-effect model was used to estimate the pooled concentrations of Pb, Cd, As, and Hg in Iranian eggs in meta-analysis. The incremental lifetime cancer risk (ILCR) and the target hazard quotient (THQ) were estimated by both calculation and Monte Carlo simulations to determine the carcinogenic and non-carcinogenic risk of egg consumption, respectively. The pooled concentrations of heavy metals in Iranian hen eggs from nine articles (11 datasets: 10 studies on Pb, 7 on Cd, and 5 on As and Hg concentrations) were Pb 0.29 (95% CI 0.20-0.39) mg kg-1, Cd 0.04 (95% CI 0.03-0.06) mg kg-1, As 0.05 (95% CI 0.03-0.07) mg kg-1, and Hg 0.03 (95% CI 0.02-0.04) mg kg-1. THQ did not show the non-carcinogenic risk; however, the ILCR for Pb concentration showed the threshold carcinogenic risk (mean ILCR = 8.94e - 4 and 9.0E - 4 by calculation and Monte Carlo simulations, respectively), with the greater risk for Cd (mean ILCR = 2.02e - 2). The carcinogenic risk of Pb and Cd concentration in Iranian hen eggs shows the urgent need for programs and policies to lower the risk for consumers by providing healthier feeding.

The association of dietary nitrates/nitrites intake and the gut microbial metabolite trimethylamine N-oxide and kynurenine in adults: a population-based study.

Background: Dietary nitrate and nitrite may affect the gut microbiota and its metabolites, such as trimethylamine N-oxide (TMAO) and kynurenine (KYN). However, this association and the exact mechanism are still unclear. Therefore, this study aimed to assess the association between dietary consumption of nitrite and nitrate on TMAO and KYN levels in adults. Methods: This cross-sectional study was employed on a subsample baseline phase of the Tehran University of Medical Sciences (TUMS) Employee's Cohort Study (TEC). A total of 250 adults aged 18 years or older were included in the current analysis. Data on the dietary intakes were collected using a validated dish-based food frequency questionnaire (FFQ), and dietary intakes of nitrite and nitrate were estimated using the FFQ with 144 items. Serum profiles and TMAO and KYN were measured using a standard protocol. Results: The findings of this study demonstrate a significant association between the intake of animal sources of nitrate and nitrite and the likelihood of having elevated levels of TMAO and KYN. Specifically, after adjustment, individuals with the highest intake adherence to nitrates from animal sources exhibited increased odds of having the highest level of TMAO (≥51.02 pg/ml) (OR = 1.51, 95% CI = 0.59-3.88, P = 0.03) and KYN (≥417.41 pg/ml) (OR = 1.75, 95% CI = 0.73-4.17, P = 0.02). Additionally, subjects with the highest animal intake from nitrite sources have 1.73 and 1.45 times higher odds of having the highest levels of TMAO and KYN. These results emphasize the potential implications of animal-derived nitrate and nitrite consumption on the levels of TMAO and KYN. Conclusion: The present evidence indicates that a high level of nitrate and nitrite intake from animal sources can increase the odds of high levels of TMAO and KYN. Further studies suggest that we should better evaluate and understand this association.

Effects of curcumin/turmeric supplementation on the liver enzymes, lipid profiles, glycemic index, and anthropometric indices in non-alcoholic fatty liver patients: An umbrella meta-analysis.

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease worldwide. The evidence for curcumin's effects on patients with NAFLD is accumulating; however, meta-analyses have reported mixed results. The current umbrella meta-analysis aimed to assess the present evidence and provide an accurate estimate of the overall effects of curcumin/turmeric on NAFLD patients. The Web of Science, Scopus, PubMed, ScienceDirect, and Google Scholar databases were searched till March 2023 using MeSH terms and related keywords based on the PICO criteria. Meta-analysis studies evaluating the effects of curcumin/turmeric supplementation on NAFLD patients that reported the effect sizes (ES) and corresponding confidence intervals (CI) were eligible for inclusion in this study. All articles were screened by considering the eligibility criteria by two independent reviewers and required data were extracted from the included meta-analyses. The meta-analysis was performed utilizing a random-effects model by STATA software. Findings of 11 meta-analyses of 99 randomized controlled trials comprising 5546 participants revealed that curcumin/turmeric supplementation reduced AST (ES = -1.072, 95% CI (-1.656, -0.488), p = 0.000), ALT (ES = -0.625, 95% CI (-1.170, -0.134), p = 0.014), and TG (ES = -0.469, 95% CI (-1.057, 0.119), p = 0.128) levels, and HOMA-IR (ES = -0.291, 95% CI (-0.368, -0.214), p = 0.000), BMI (ES = -0.205, 95% CI (-0.304, -0.107), p = 0.000), and WC (ES = -1.290, 95% CI (-2.038, -0.541), p = 0.001) in comparison to the control group. However, the effects of curcumin on GGT, ALP, TC, LDL-C, HDL-C, FBS, and HbA1C levels and body weight were not significant. The findings suggest the beneficial effects of curcumin/turmeric supplementation in patients with NAFLD, such as improving liver function, decreasing serum TG levels, ameliorating insulin resistance, and reducing general and central obesity. Nevertheless, high-quality research is further required to prove these achievements.

A systematic review with meta-analysis of the relation of aflatoxin B1 to growth impairment in infants/children.

BACKGROUND: Aflatoxins are regarded as the most potent genotoxic and carcinogenic type of mycotoxins. This meta-analysis was performed to investigate a the relation of aflatoxin B1 (AFB1) to growth measurements of infants/children, including wasting, underweight, stunting, as well as weight-for-age (WAZ), height-for-age (HAZ), and weight-for-height (WHZ) z-scores. METHODS: Electronic databases of PubMed, Web of Science, and Scopus were searched to identify related publications. Effect sizes for associations were pooled using the random effects analysis. Subgroup analysis by study design, method used to assess AFB1, and adjustment for covariateswas performed to detect possible sources of heterogeneity. RESULTS: Pooled analysis of available data showed that AFB1 exposure was negatively associated growth z-scores, including WHZ (ß = -0.02, 95%CI = -0.07 to 0.03), with WAZ (ß = -0.18, 95%CI = -0.33 to -0.02), and HAZ (ß = -0.17, 95%CI = -0.30 to -0.03) in infants/children. There was a remarkable heterogeneity among studies on WAZ and HAZ (P ≤ 0.001). In prospective cohort studies, AFB1 exposure was found to be significantly associated with the elevated risk of underweight (OR = 1.20, 95%CI = 1.03 to 1.40) and stunting (OR = 1.21, 95%CI = 1.11 to 1.33). CONCLUSIONS: This meta-analysis highlighted the importance of AFB1 exposure as a potential risk factor for growth impairment in infants/children.

The effects of purslane consumption on lipid profile and C-reactive protein: A systematic review and dose-response meta-analysis.

Earlier investigations into the impact of purslane, Portulaca oleracea, on lipid profile and C-reactive protein (CRP) produced contradictory findings. The effect of purslane consumption on lipid profiles and CRP was assessed in this comprehensive review and meta-analysis. We conducted a thorough literature search in online databases, including PubMed, Scopus, the Cochrane library, and ISI Web of Science to find relevant randomized controlled trials up to June 2023. By incorporating 14 effect sizes from 13 RCTs, we were able to show that purslane consumption significantly decreases serum triglyceride (TG) (WMD: -16.72, 95% CI: -22.49, -10.96 mg/dL, p < .001), total cholesterol (TC) (WMD: -9.97, 95% CI: -19.86, -0.07 mg/dL, p = .048), and CRP (WMD: -1.22, 95% CI: -1.63, -0.80 mg/L, p < .001) levels in patients compared to the control group. In addition, purslane consumption significantly increases high-density lipoprotein (HDL-C) (WMD: 4.09, 95% CI: 1.77, 6.41 mg/dL, p = .001) levels. However, purslane consumption did not affect low-density lipoprotein (LDL-C) levels. According to a suggested optimal dosage, purslane consumption is considered to be safe up to 30 g/day. Purslane consumption can significantly improve cardiovascular health by improving lipid profile and inflammation status.

The effects of purslane consumption on glycemic control and oxidative stress: A systematic review and dose-response meta-analysis.

Purslane (Portulaca oleracea L.) is a herbal remedy with wide range of pharmaceutic properties. Although the beneficial effect of purslane on the treatment of Type 2 Diabetes Mellitus (T2DM) has been shown, there is an inconsistency among the results of previous studies. Therefore, this study is aimed at conducting a systematic review and meta-analysis on the effect of purslane on glycemic profile and oxidative stress markers. A systematic search was performed in the Scopus, Web of science, PubMed and the Cochrane Library to find articles related to the effect of the purslane on Malondialdehyde (MDA) and Total Antioxidant Capacity (TAC), Fasting Blood Sugar (FBS), Hemoglobin A1c (HbA1c), insulin resistance, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) up to September 2022. Among the 611 initial studies that were identified from searching electronic databases, 16 Randomized Clinical Trials (RCTs) involving 1122 participants (557 cases and 565 controls) were included for data analysis. The results of random-effects modeling demonstrated that purslane consumption significantly reduced FBS (p < .001), MDA (p < .001) and increased TAC (p < .001). However, purslane consumption did not affect HbA1c (p < .109), fasting insulin (p = .298) and HOMA-IR (p = .382). Meta-analyses were performed using both the random- and fixed-effects model where appropriate, and I 2 index was used to evaluate the heterogeneity. This meta-analysis study suggests that purslane has beneficial effects on oxidative stress markers and glycemic parameter. Therefore, it may be a promising adjuvant therapy in T2DM because of its benefits and negligible adverse effects.

Mercury Exposure and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis.

Methods: Scopus and PubMed databases were systematically searched from their inception to November 2021 to obtain pertinent studies. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate the difference in Hg levels between people with and without T2DM. The association of the Hg exposure with T2DM was assessed using a random-effects model by pooling the odds ratios (ORs) and 95% CIs. Results: A total of 17 studies, with 42,917 participants, aged ≥18 years, were analyzed. Overall, Hg levels were significantly higher in T2DM patients compared with non-T2DM controls (SMD = 1.07; 95%CI = 0.59 to 1.55, P ≤ 0.001), with significant heterogeneity across studies (I2 = 96.1%; P=≤0.001). No significant association was found between Hg exposure and risk of T2DM in the overall analysis and subgroup analysis based on the source of sample and study design. However, higher exposure to Hg was related to reduced risk of T2DM in men (OR = 0.71; 95%CI = 0.57 to 0.88), but not in women. No significant evidence for publication bias was detected. Conclusions: Although the Hg level in T2DM is significantly higher than that of nondiabetics, there was no association between Hg exposure and the overall risk of T2DM. Nevertheless, our study shows that higher exposure to Hg might reduce the risk of T2DM in men.

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 (I 2 = 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.

Identification of a Novel Homozygous Mutation in BBS10 Gene in an Iranian Family with Bardet-Biedl Syndrome.

BACKGROUND: Bardet-Biedl Syndrome (BBS) is a rare pleiotropic autosomal recessive disease related to ciliopathies with approximately 25 causative genes. BBS is a multisystemic disorder with wide spectrum of manifestations including truncal obesity, retinal dystrophy, male hypogenitalism, postaxial polydactyly, learning difficulties, and renal abnormalities. METHODS: A consanguineous Iranian family with a 28-year-old daughter affected with BBS, resulting from a first cousin marriage, was examined. After clinical examination, Whole Exome Sequencing (WES) was applied. Following the analysis of exome data, Sanger sequencing was used to confirm as well as to co-segregate the candidate variant with the phenotype. RESULTS: A novel homozygous variant [c. 2035G>A (p.E679K)] in exon 2 of the BBS10 gene was found which was categorized as likely pathogenic based on American College of Medical Genetics and Genomics (ACMG) guidelines and criteria. In this study, the variant was fully co-segregated with the phenotype in the family. CONCLUSION: Despite overlapping with other ciliopathies in terms of the phenotype, the BBS has high genetic heterogeneity and clinical variability even among affected members of a family. The symptoms observed in patients are largely related to the genes involved and the type of mutations in the BBS. In this study, in addition to phenotype description of the proband harboring a novel disease-causing variant in BBS10 gene, the spectrum of BBS symptoms was expanded. The findings of this study can be useful in genetic counseling, especially for risk estimation and prenatal diagnosis.

Effect of infant formula supplemented with prebiotics and probiotics on incidence of respiratory tract infections: A systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Previous investigations have proposed that the consumption of infant formula supplemented with prebiotics, probiotics and synbiotics (PRO-formula) may have protective impacts on respiratory tract infections (RTIs). Nevertheless, the findings of studies are contradictory. This meta-analysis aimed to explore the influence of PRO-formula on RTIs in infants by pooling randomized controlled trials (RCTs). METHODS: To obtain eligible RCTs, Scopus and PubMed databases were systematically searched from their inception to November 2020. A random-effects model was applied to pool the relative risks (RR) and corresponding 95% confidence intervals (CI) for RTIs following consumption of PRO-formula. RESULTS: A total of 15 RCTs, with a total sample size of 3805 participants (1957 for intervention and 1848 for placebo), were included in the present meta-analysis. In the overall analysis, in comparison to placebo, consumption of PRO-formula had a significant protective impact against RTIs (RR = 0.89, 95%CI: 0.82-0.97) in infants, with a remarkable evidence of heterogeneity across studies (I2 = 61.4%, P < 0.001). In the meta-regression analysis, the effect of PRO-formula on RTIs was not modified by the follow-up duration. No evidence for publication bias was detected. CONCLUSIONS: Administration of PRO-formula may be a potential approach for the prevention of respiratory tract infections in infants.

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.

Effect of probiotic fermented dairy products on incidence of respiratory tract infections: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Previous studies have suggested that the consumption of probiotic fermented dairy products (PFDP) may have a protective effect on respiratory tract infections (RTIs). However, the results of studies are inconclusive. We aimed to systematically investigate the effect of PFDP on RTIs by performing a meta-analysis of randomized controlled trials (RCTs). METHODS: PubMed and Scopus databases were systematically searched up to October 2020 to identify eligible RCTs. Meta-analysis outcomes were risk of incidence of upper (URTIs ) and lower (LRTIs ) respiratory tract infections. A random-effects model was used to pool the relative risks (RR) and corresponding 95 % confidence intervals (CI) for outcomes following conception of PFDP. RESULTS: A total of 22 RCTs, with a total sample size of 10,190 participants, were included in this meta-analysis. Compared with placebo, consumption of PFDP had a significant protective effect against RTIs in the overall analysis (RR = 0.81, 95 %CI: 0.74 to 0.89) and in children (RR = 0.82, 95 %CI: 0.73 to 0.93), adults (RR = 0.81, 95 %CI: 0.66 to 1.00), and elderly population (RR = 0.78, 95 %CI: 0.61 to 0.98). The significant decreased risk of RTIs was also observed for URTIs (RR = 0.83, 95 %CI: 0.73 to 0.93), while, this effect was marginal for LRTIs (RR = 0.78, 95 %CI: 0.60 to 1.01, P = 0.06). The disease-specific analysis showed that PFDP have a protective effect on pneumonia (RR = 0.76, 95 %CI: 0.61 to 0.95) and common cold (RR = 0.68, 95 %CI: 0.49 to 0.96). CONCLUSIONS: Consumption of PFDP is a potential dietary approach for the prevention of RTIs.

Glycemic index, but not glycemic load, is associated with an increased risk of metabolic syndrome: Meta-analysis of observational studies.

BACKGROUND: Diets with high glycemic index (GI) or high glycemic load (GL) have been linked to important risk factors associated with the development of metabolic syndrome (MetS), such as dyslipidemia, higher blood glucose, and insulin concentrations. However, the role of GI and GL in relation to Mets is still understudied and controversial. This review, therefore, assessed whether high GI or GL contribute to development of Mets. METHODS: A systematic search of four bibliographic databases was conducted (MEDLINE/PubMed, EMBASE, Web of Sciences, and Scopus) from inception to January 2020 for observational studies assessing GI/GL in relation to MetS. Risk estimates were pooled using random-effect models for the highest versus lowest intake categories, and assessed for heterogeneity using subgroup analysis. The dose-response nature of the relationship was also investigated. Sensitivity analysis and Egger test were used to check the robustness of findings and the possibility of publication bias, respectively. RESULTS: Data from 12 publications (one cohort study and eleven cross-sectional studies) with a total sample size of 36,295 subjects are included. The pooled effect sizes from the nine studies indicated high versus low dietary GI was associated with increased risk of MetS (OR = 1.05, 95% CI: 1.01 to 1.09) (I2  = 58.1, P = .004). This finding was supported by all subgroup analyses except where studies used 24-h recalls for dietary assessment. Additionally, a linear dose-response investigation revealed that each 5-point increment in GI was associated with 2% increase in the risk of MetS (OR = 1.02, 95% CI: 1.01 to 1.02); non-linear pattern was insignificant, however (p-nonlinearity = 0.63). Moreover, pooled effect sizes from ten studies suggested that no association was found between the GL and MetS with results remaining consistent in all subgroup analyses. CONCLUSION: A diet with lower GI may protect against MetS. Nutrition policy and clinical practices should encourage a diet with low GI. Future studies should include both GI and GL and different criteria of MetS to provide a better comparison.

A Meta-analysis of Randomized Controlled Trials of the Effect of Probiotic Food or Supplement on Glycemic Response and Body Mass Index in Patients with Type 2 Diabetes, Updating the Evidence.

BACKGROUND: To investigate the effects of probiotics on glucose metabolism and body mass index (BMI), and compare the efficacy of probiotic food with the probiotic supplement in patients with type 2 diabetes mellitus using a meta-analysis of randomized, controlled trials. METHODS: Online databases Embase, Web of Science, and PubMed were searched until November 2019 to identify eligible articles. Fourteen trials were included. RESULTS: Probiotic consumption reduced fasting plasma glucose (FPG) (SMD=-0.38, 95% CI: -0.76 to 0.01), glycosylated hemoglobin (HbA1c) (SMD=-0.64, 95% CI: -0.91 to -0.38), fasting insulin concentration (SMD=-0.48, 95% CI, -0.81 to -0.15), HOMA-IR (SMD=-1.01, 95% CI, -1.51 to -0.52), and BMI (SMD=-0.02, 95%CI, -0.17 to 0.13) in intervention groups compared with control groups. Subgroup analysis was conducted to trials with probiotic foods and probiotic supplements. Both of probiotic foods (SMD: -0.65, 95% CI: -1.04 to -0.26; SMD: -1.17, 95% CI: -2.14 to -0.20, respectively) and supplements (SMD: -0.64, 95% CI: -1.01 to -0.27; SMD: -0.98, 95% CI: -1.55 to -0.40, respectively) made significant reduction in HbA1c and HOMA.IR. Meta-analysis of trials with probiotic foods found non-significant changes in FBG and fasting insulin concentration (SMD: 0.11, 95% CI: -0.52 to 0.75; SMD: -0.14, 95% CI: -0.48 to 0.20, respectively); however the changes in trials with probiotic supplements were significant (SMD: -0.73, 95% CI: -1.22 to -0.23; SMD: -0.57, 95% CI: -0.97 to -0.17, respectively). Probiotic foods cause a non-significant raise in BMI (SMD: 0.23, 95% CI: -0.03 to 0.49); however, meta-analysis of trials with probiotic supplements found a non-significant reduction in BMI (SMD: -0.13, 95% CI: -0.31 to 0.04). CONCLUSION: The present meta-analysis suggests that consuming probiotics could improve glucose metabolism and affect body weight, with a potentially greater effect when probiotics are used as supplements.

RPE65 and retinal dystrophy: Report of new and recurrent mutations.

BACHGROUND: Leber congenital amaurosis (LCA) is a severe and congenital or early onset form of inherited retinitis pigmentosa (RP). To date, approximately 25 genes have been introduced in relation to LCA. In this regard, retinal pigment epithelium-specific 65 kDa (RPE65) is a well-known gene mutation that plays a role in the pathogenesis of 5-10% of LCA cases. METHOS: Two individuals fromseparate families were subjected to ehole exome sequencing (WES). Causativevariants were searched further assessed using Sanger sequencing. RESULTS: Here, two families with mutations in the RPE65 gene show severe and early onset LCA, as expected. In addition to the characterization of the phenotype, by reporting a new mutation (c.1451-1G>A), we further expand the mutation spectrum of RPE65. Likewise, as an interesting aspect of our study, we report on a previously reported RP-linked mutation associated with severe early onset LCA (c.T200G:p.L67R). CONCLUSIONS: Considering this variant in different populations, it is likely that it represents a hotspot and affects the function of the coded protein. The variable expressivity of the phenotype can be assumed by the presence of the modifier allele(s) as a result of a different genetic background or the effect of different environments on phenotype expression.