Search

The impact of sumac supplementation was not previously examined in patients with metabolic syndrome (MetS). So, we investigated the influence of sumac supplementation on insulin resistance, inflammation, oxidative stress, and antioxidant markers in adults with MetS. The current study was a single‐center, triple‐blind, randomized, placebo‐controlled crossover clinical trial that was conducted on 47 patients with MetS. Participants were randomly divided into two groups of intervention and control in the first phase. They received capsules containing 500 mg sumac or placebo (lactose) twice a day, after lunch and dinner, for 6 weeks. After a 2‐week washout period, the subjects crossed over to the alternate arm. In both arms, fasting venous blood samples were obtained at baseline and at the sixth week of the intervention to determine glycemic status, high‐sensitivity C‐reactive protein (hs‐CRP), malondialdehyde (MDA), total antioxidant capacity (TAC), and antioxidant enzymes activity. The mean (±SD) age, weight, and body mass index of participants were respectively 58.7 ± 5.83 years, 79.9 ± 14.35 kg, and 31.6 ± 4.6 kg/m2; 80.9% of subjects were females (n = 38). Based on per‐protocol analyses, the serum fasting insulin concentration was unexpectedly decreased in the placebo group (change in sumac vs. control: 0.95 ± 3.9 vs. −1.17 ± 3.9 mU/L; p = 0.04). Sumac supplementation, compared to control, has marginally enhanced catalase activity (change in sumac vs. control: 2.91 ± 9.5 vs. −1.07 ± 9.1 nmol/min/ml; p = 0.06). This supplementation has also increased serum TAC and the activity of superoxide dismutase, but these changes were not significant. This intervention did not affect other insulin resistance, inflammatory, or oxidative stress markers. We found that 1 g/day sumac consumption for 6 weeks, as adjuvant therapy, could improve the antioxidant defense system in adults with MetS but did not affect insulin resistance, inflammation, or oxidative stress. [ABSTRACT FROM AUTHOR]

Context Findings of previous observational studies that examined the association between circulating vitamin D levels and lipid profiles have been inconsistent. Objective A dose-response meta-analysis of epidemiologic studies was conducted to investigate the relationship between serum 25-hydroxyvitamin D levels and dyslipidemia in adults. Data Sources Electronic databases were searched systematically for articles published up to June 2021. Data Extraction Fifty-seven observational studies and 2 cohort studies that reported odds ratios (ORs) or relative risks (RRs) with 95%CIs for dyslipidemia in relation to serum 25-hydroxyvitamin D levels in adults were included. Data Analysis A high level, vs a low level, of serum 25-hydroxyvitamin D was related to a significant 19% decrease in the odds of hypertriglyceridemia (OR 0.81; 95%CI, 0.74–0.89), an 18% reduction in low high-density lipoprotein cholesterol (HDL-C) (OR 0.82; 95%CI, 0.76–0.89), and an 18% reduction in dyslipidemia (OR 0.82; 95%CI, 0.75–0.91). No significant association was found between a high vs a low level of serum 25-hydroxyvitamin D and risk of high low-density lipoprotein cholesterol (LDL-C) levels (OR 0.86; 95%CI, 0.62–1.19) or hypercholesterolemia (OR 1.03; 95%CI, 0.93–1.15). Dose-response analyses demonstrated that each 10 ng/mL increase in the serum 25-hydroxyvitamin D level was linked, respectively, to a 7% (OR 0.93;95%CI, 0.85–1.02), a 3% (OR 0.97; 95%CI, 0.90–1.05), and a 4% (OR 0.96; 95%CI, 0.92–1.00) marginally significant decrease in the odds of hypertriglyceridemia, low HDL-C, and dyslipidemia. Conclusion Higher serum 25-hydroxyvitamin D levels are associated with significant reductions in the odds of hypertriglyceridemia, low HDL-C, and dyslipidemia in a dose-response trend. Systematic Review Registration PROSPERO registration no. CRD42021219484. [ABSTRACT FROM AUTHOR]

Findings of observational studies that investigated the relationship between vitamin D deficiency and abnormal glucose homeostasis were contradictory. This meta-analysis of epidemiologic studies evaluated the association of vitamin D status and risk of type-2 diabetes (T2D) and prediabetes in adults. A systematic search was conducted on all published articles in five electronic databases (including MEDLINE/PubMed, EMBASE, Institute for Scientific Information, Scopus and Google scholar), up to August 2020. Twenty-eight prospective cohort and nested case-control studies and 83 cross-sectional and case-control investigations that reported relative risks (RRs) or odds ratios (ORs) with 95% confidence intervals (CIs) for abnormal glucose homeostasis in relation to serum vitamin D levels in adults were included in the analysis. In prospective studies, high versus low level of vitamin D was respectively associated with significant 35%, 30% and 51% decrease in risk of T2D (RR:0.65; 95%CI: 0.55–0.76; 27 effect sizes), combined T2D and pre-diabetes (RR:0.70; 95%CI: 0.52–0.95; 9 effect sizes) and pre-diabetes (RR:0.49; 95%CI: 0.26–0.93; 2 effect sizes). These inverse associations were significant in almost all subgroups. Dose–response analysis in prospective studies showed that each 10 ng/ml increase in serum vitamin D levels resulted in 12% and 11% reduced risk of T2D (RR:0.88; 95%CI: 0.83–0.94) and combined T2D and prediabetes (RR:0.89; 95%CI: 0.87–0.92), respectively. In cross-sectional and case-control studies, highest versus lowest level of serum vitamin D was linked to reduced odds of T2D (OR:0.64; 95%CI: 0.57–0.72; 42 effect sizes) and combined T2D and pre-diabetes (OR:0.79; 95%CI: 0.74–0.85; 59 effect sizes); but not pre-diabetes (OR:0.64; 95%CI: 0.17–2.37; 11 effect sizes). This meta-analysis of epidemiologic studies disclosed that serum vitamin D level was reversely associated with the risk of T2D and combined T2D and prediabetes in adults, in a dose–response manner. However, the association was not remarkable for pre-diabetes. [ABSTRACT FROM AUTHOR]

Context Although previous observational studies have investigated the association between waist circumference (WC) values and serum vitamin D levels, findings have been inconsistent. Objective A systematic review and meta-analysis was performed to evaluate the effect of abdominal obesity (based on WC) on vitamin D deficiency or insufficiency in adults. Data Sources A systematic search of the published literature up to September 2020 was conducted in electronic databases, including MEDLINE (PubMed), EMBASE, Institute for Scientific Information (ISI) (Web of Science), Scopus, and Google Scholar, for observational studies that investigated the association between abdominal obesity (based on WC) or different categories of WC as the exposure and serum 25-hydroxy vitamin D levels as the outcome. Data Extraction Eighteen cross-sectional studies were included in the review. The relationship between WC values and combined serum vitamin D deficiency and insufficiency (<30 ng/mL) or vitamin D deficiency (<20 ng/mL) was evaluated. Data Analysis Combining 8 effect sizes from 5 investigations, including 7997 individuals, illustrated that the highest category of WC, compared with the lowest category of WC, was related to 82% increased odds of combined serum vitamin D deficiency and insufficiency (<30 ng/mL) (OR: 1.82; 95% CI: 1.34, 2.49). Moreover, in studies that investigated both genders together, the highest category of WC, compared with the lowest category of WC, was associated with 61% increased odds of serum vitamin D deficiency (<20 ng/mL) (OR: 1.61; 95% CI: 1.12, 2.31). The same results were obtained for almost all subgroups for several covariates. Conclusion This meta-analysis of cross-sectional studies confirmed that increased WC was related to the elevated risk of combined vitamin D deficiency and insufficiency in adults. More prospective studies are needed to confirm causality. Systematic Review Registration PROSPERO registration no. CRD42020190485. [ABSTRACT FROM AUTHOR]

Background: Several studies investigated serum vitamin D-dyslipidemia relation in children and adolescents, but findings were contradictory. We evaluated this association in children and adolescents by a systematic review and doseresponse meta-analysis. Methods: All published articles were searched using electronic databases up to December 2022. Observational studies which investigated odds of dyslipidemia in categories of serum vitamin D levels in children were included. Results: Pooling 17 effect sizes from 15 studies (39,342 participants) showed that subjects with higher serum vitamin D had 27% lower odds of hypertriglyceridemia (OR=0.73; 95%CI: 0.60, 0.88). A meta-analysis on 18 effect sizes from 16 studies (39,718 participants) illustrated that highest vs. lowest serum vitamin D was related to 22% lower odds of low high-density lipoprotein cholesterol (HDL-c) (OR=0.78; 95%CI: 0.66, 0.91). We also found non-linear associations between serum vitamin D and odds of abnormal lipid profile. Such that, elevating values of 25-hydroxyvitamin D from 35 to 55 nmol/L was along with a decreasing trend in odds of hypertriglyceridemia, hyper low-density lipoprotein (LDL) cholesterolemia, hypercholesterolemia, and hypo HDLcholesterolemia. However, no significant linear association was observed. Based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE), the certainty of all evidences was rated as high. Conclusion: This meta-analysis revealed that 25-hydroxyvitamin D was inversely related to odds of abnormal serum triglyceride (TG) and HDL-c in children and adolescents. Increasing serum vitamin D from 35 to 55 nmol/L was along with a decreasing trend in odds of abnormal serum TG, HDL-c, LDL-c and total cholesterol in children. [ABSTRACT FROM AUTHOR]

Summary: Although several observational studies have investigated the relationship between vitamin D deficiency and risk of central obesity, the results were inconsistent. We performed a dose–response meta‐analysis on epidemiologic studies that evaluated the association of vitamin D status and abdominal obesity in adults. A systematic search was carried out of all published articles, up to May 2020, in five electronic databases, including MEDLINE (Pubmed), EMBASE, Institute for Scientific Information (ISI) (Web of science), Scopus and Google scholar. Forty‐one observational studies reported odds ratios (ORs) or relative risks (RRs) with 95% confidence intervals (CIs) for abdominal obesity in relation to serum vitamin D levels in adults were included in the analysis. Using a random effects model, the overall effect size was calculated. Combining 44 effect sizes from 36 cross‐sectional studies with 257,699 participants revealed that the highest versus the lowest serum vitamin D level was significantly associated with a 23% decreased odds of abdominal obesity (OR: 0.77; 95% CI [0.71, 0.83]). This inverse association was significant in almost all subgroups based on different covariates. Dose–response analysis showed that each 25 nmol/L increase in serum vitamin D was related to 8% reduced risk of abdominal obesity (OR: 0.92; 95% CI [0.85, 0.99]). When we confined the analysis to 23 effect sizes from 17 studies with representative population (242,135 participants), the same results were obtained (OR: 0.79; 95% CI [0.71, 0.87]). Dose–response analysis indicated that each 25 nmol/L increase in blood vitamin D levels was linked to 10% decreased central adiposity risk in representative populations (OR: 0.90; 95% CI [0.82, 0.99]). This meta‐analysis of epidemiologic studies revealed that serum vitamin D level was inversely associated with risk of abdominal obesity in adults, in a dose–response manner. The same findings were obtained in representative populations. Further prospective studies are required to examine the causal association between serum vitamin D levels and abdominal obesity. [ABSTRACT FROM AUTHOR]

Introduction: Metabolic syndrome (MetS) is a group of metabolic disorders known as mortality cause. Metabolic syndrome has multifactorial causes such as genetics, age, and the most important ones are lifestyle changes such as nutrients status. Although the relation between zinc and MetS was previously investigated, the findings were inconsistent. Therefore, we performed a systematic review and doseresponse meta-analysis to summarize the relationship between blood zinc and MetS in adults. Search Strategy: ISI Web of Science, Medline (PubMed), Scopus, and motor engineering of Google Scholar were systematically searched, by using the concepts of zinc, MetS, and related keywords, up to November 2023. Observational studies were included if reported blood zinc as exposure and MetS as an outcome in adults, with relative risks (RRs), odds ratios (ORs), or hazard ratios (HRs) and 95% confidence intervals (CIs) for the relation of blood selenium and MetS. Analyses were conducted using the random effect model. Additionally, sensitivity analysis, metregression, and dose-response analysis were conducted. All analyses were conducted through the use of STATA version 14.0. Results: The current systematic review and meta-analysis included 20,740 participants and 6,003 cases with MetS from 8 cross-sectional, 3 case-control, and 2 cohort studies. The highest versus lowest levels of circulating zinc were related to 40% higher odds of MetS (95%CI: 1.12, 1.75). Considering the significant between-study heterogeneity (I2=75.5% P<0.001), subgroup analysis was conducted based on potential confounders. In the non-Asian countries, this relationship was also significant and heterogeneity disappeared. Nevertheless, in the Asian countries, there was not any significant association and heterogeneity remained significant. Moreover, the linear dose-response analysis indicated that each 200 µg/L increment in circulating zinc was along with 12% higher odds of MetS (95%CI: 1.06-1.19). Conclusion: The current analysis revealed a straight association between blood zinc and risk of MetS in adults, in a dose-response manner. More prospective investigations are required to confirm these findings. [ABSTRACT FROM AUTHOR]

Background: Although there are several investigations on the relation of serum vitamin D with pre-diabetes and type 2 diabetes mellitus (T2DM) in children and adolescents, their findings are inconsistent. Therefore, we conducted a systematic review and doseresponse meta-analysis to summarize this subject. Methods: Electronic databases of Web of Science, Scopus, PubMed and motor engineering of Google Scholar were comprehensively searched up to May 2023. Epidemiologic studies which investigated the risk of hyperglycemia and insulin resistance in relation to serum 25-hydroxy vitamin D in children and adolescents were included. Results: Twenty-two investigations with 38,622 participants were systematically reviewed. Metaanalysis on 15 studies (32,720 participants) showed that subjects with the highest serum vitamin D had 42% lower odds of hyperglycemia, compared with those in the lowest category of serum vitamin D (OR=0.58; 95%CI: 0.48, 0.71). Moreover, pooling 8 studies (10,465 subjects) illustrated that highest vs. lowest serum vitamin D was related to 44% lower odds of insulin resistance (OR=0.56; 95%CI: 0.37, 0.83). Based on linear dose-response analysis, each 10 nmol/L increase in serum 25-hydroxy vitamin D was associated to 6% decreased odds of hyperglycemia and insulin resistance in children. Furthermore, non-linear dose-response analysis revealed that increasing serum vitamin D from 40 nmol/L to normal values was along with a decreasing trend in hyperglycemia and insulin resistance. Conclusion: This meta-analysis revealed an inverse association between serum vitamin D and hyperglycemia and insulin resistance in children and adolescents, in a dose-response manner. Increasing serum vitamin D from 40 nmol/L to normal values was along with a decreasing trend in hyperglycemia and insulin resistance odds. [ABSTRACT FROM AUTHOR]

This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to test our hypothesis that herbal tea may improve anthropometric parameters, metabolic factors, and hormone levels in women with polycystic ovarian syndrome (PCOS). A literature search was conducted on Information Sciences Institute, Medline (PubMed), Scopus, Embase, and Google Scholar, up to March 2023 without applying language or date restrictions. RCTs that assigned herbal tea vs. placebo on PCOS women and evaluated changes in anthropometric measurements, metabolic indices, or hormonal profiles were included. Six RCTs with 235 PCOS women (119 in the intervention and 116 in the control group) were included. Meta-analysis showed that herbal tea consumption led to significant decreases in weight (weighted mean difference [WMD], -2.02 kg; 95% confidence interval [CI], -3.25, -0.80), body mass index (BMI) (WMD, -0.88 kg/m 2 ; 95% CI, -1.47, -0.28) and fasting blood glucose (FBG) (WMD, -6.47 mg/dL; 95% CI, -8.49, -4.45), compared to the control group. Herbal tea supplementation has also significantly increased follicle-stimulating hormone (FSH) concentration (WMD, 0.56 IU/L; 95% CI, 0.17, 0.95). Meanwhile, the effect of herbal tea on the waist/hip ratio, hip circumference, waist circumference, body fat, fasting insulin, FBG/insulin ratio, luteinizing hormone, total testosterone, and dehydroepiandrosterone sulfate was not significant. Herbal tea might be a potential supplemental therapy to manage weight, BMI, FBG, and FSH in PCOS women. Further large randomized clinical trials are recommended to affirm these findings., Competing Interests: Conflict of Interest: The authors declare that they have no competing interests., (Copyright © 2024. The Korean Society of Clinical Nutrition.)

Context: Although several investigations have been conducted on the association between serum vitamin D levels and prediabetes and type 2 diabetes mellitus (T2DM) in children and adolescents, their findings are inconsistent., Objective: We conducted a systematic review and dose-response meta-analysis to summarize this subject., Data Sources: The electronic databases of ISI Web of Science, Scopus, PubMed, and motor engineering of Google Scholar were comprehensively searched up to May 2023., Data Extraction: Epidemiologic studies that investigated the risk of hyperglycemia and insulin resistance in relation to serum 25-hydroxy vitamin D levels in children and adolescents were included., Data Analysis: Twenty-two investigations, with a total of 38 622 participants, were systematically reviewed. Meta-analysis of 15 studies (n = 32 720 participants) showed that participants with the highest serum vitamin D levels had 42% lower risk of hyperglycemia, compared with those in the lowest category of serum vitamin D levels (relative risk [RR] = 0.58; 95%CI, 0.48, 0.71). Moreover, pooling 8 studies (n = 10 465 participants) illustrated that highest serum vitamin D level was associated with a 44% lower risk of insulin resistance compared with the lowest serum vitamin D level (RR = 0.56; 95%CI, 0.37, 0.83). Based on linear dose-response analysis, each 10 nmol/L increment in serum 25-hydroxy vitamin D was associated with a 6% decreased risk of hyperglycemia and insulin resistance in children. Furthermore, nonlinear dose-response analysis revealed that increasing serum vitamin D concentration from 40 nmol/L to sufficient values (>50 nmol/L) was associated with a decreasing trend in risk of hyperglycemia and insulin resistance., Conclusion: This meta-analysis revealed inverse associations between serum vitamin D levels and hyperglycemia and insulin resistance in children and adolescents, in a dose-response manner. Increasing serum vitamin D concentration from 40 nmol/L to sufficient values (>50 nmol/L) was associated with a decreasing trend in hyperglycemia and insulin resistance risk. Systematic Review Registration: PROSPERO registration no. CRD42023458155., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: The relation of magnesium (Mg) intake with depression was previously investigated by meta-analyses. However, due to limited data, a dose-response analysis was not performed., Objective: Considering the recently published articles, a systematic review and dose-response meta-analysis was conducted to summarize the relation of dietary Mg intake with depression in adults., Data Sources: Medline (PubMed), ISI Web of Science, Scopus, and Google Scholar were comprehensively searched up to August 2023., Data Extraction: Observational studies that reported the relation of dietary Mg intake and depression in adults were included and their data were extracted., Data Analysis: A total of 63 214 participants from 10 cross-sectional and 3 cohort studies were included in the current study. Pooling 15 effect sizes from 12 studies (including 50 275 participants) revealed that individuals with the highest Mg intake had a 34% lower risk of depression, compared with those with the lowest Mg intake (RR: 0.66; 95% CI: 0.57, 0.78). Moreover, the linear dose-response analysis revealed that each 100-mg/d increment in Mg intake was associated with a 7% reduced risk of depression (RR: 0.93; 95% CI: 0.90, 0.96). Additionally, based on nonlinear dose-response analysis, increasing Mg intake from 170 to 370 mg/d was associated with a reduced risk of depression. Analyses were also conducted on 9 studies (49 558 participants) with representative populations, and similar results were found in the meta-analysis (RR: 0.71; 95% CI: 0.61, 0.83) and linear (RR: 0.93; 95% CI: 0.90, 0.96) and nonlinear dose-response analysis., Conclusion: The current study shows an inverse dose-dependent association between dietary Mg intakes and risk of depression in both a general and representative population of adults in a dose-response manner., Systematic Review Registration: PROSPERO registration no. CRD42024506570., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)