Diabetes Risk Reduction Diet (DRRD) and Breast Cancer Risk: A Review.

BACKGROUND: Considering the significant involvement of insulin resistance in various forms of cancer, it is postulated that the implementation of a diabetic diet, which effectively mitigates insulin resistance, may potentially decrease the susceptibility to breast cancer among female individuals. METHODS: In this literature review, a comprehensive electronic search of different databases was done using the keywords "Breast cancer" OR "breast tumor" OR "Breast Neoplasms" AND "diet" OR "diabetic diet" OR "Low Carbohydrate Diet" OR "Carbohydrate restricted diet" OR "High-Protein Low-Carbohydrate Diet" OR "diabetes risk reduction diet" OR "DRRD" as the main keywords. RESULTS: Research has shown that the DRRD score is inversely correlated with breast cancer risk. In fact, for every three-point increase in the DRRD score, the risk of breast cancer decreases by 7%. Studies have shown that higher DRRD scores in breast cancer patients are associated with a reduced risk of cancer and a higher chance of survival. CONCLUSION: The results of this study indicate a positive correlation between a higher level of adherence to the diabetes risk reduction diet (DRRD) and improved survival rates. This suggests that breast cancer survivors may benefit from making dietary modifications in line with a diabetic diet following their diagnosis.

Oxidative balance score and risk of cancer: a systematic review and meta-analysis of observational studies.

BACKGROUND: The oxidative balance score (OBS) has been utilized to assess the overall pro- and antioxidant exposure status in various chronic diseases. The current meta-analysis was carried out to pool the association between OBS and the risk of cancer. METHODS: We systematically searched the Web of Science, PubMed, Scopus, Embase, and Google Scholar up to August 2023. All observational studies which evaluated the association of OBS with the risk of cancers were included. There was no time of publication or language restrictions. Heterogeneity between studies was assessed using the Chi-square-based Q-test and the I2. A random-effects model meta-analysis was conducted to estimate the pooled effect sizes. Possible sources of heterogeneity were explored by subgroup and meta-regression analysis. RESULTS: Totally, 15 studies (9 case-control and 6 cohorts) were eligible for meta-analysis. Random effect model meta-analysis of case-control studies showed that higher OBS significantly decreases the odds of cancers (pooled OR: 0.64, 95% CI: 0.54, 0.74). In the cohort studies, the association of OBS with the risk of cancers was not significant (pooled HR: 0.97, 95% CI: 0.80,1.18). The subgroup analysis showed that cancer type and gender were the potential sources of heterogeneity. CONCLUSION: Our results show an inverse and significant association between higher OBS and odds of colorectal cancers in case-control and cohort studies. In the case of prostate cancer in cohort studies, our results did not align with the hypothesis. Considering the importance of diet and antioxidant balance in the conditions of malignancy, it is suggested to conduct more comprehensive studies with standard measurement methods to obtain conclusive results.

Association between Levels of Trimethylamine N-Oxide and Cancer: A Systematic Review and Meta-Analysis.

Cancer is the second leading cause of death in the world. Reports on the effect of Trimethylamine-N-oxide (TAMO), a small amine oxide generated by gut microbial metabolism of choline, betaine, and carnitine, on cancer are inconsistent. Therefore, this systematic review and meta-analysis summarize the effect of TAMO on cancer incidence. A systematic search was conducted in PubMed, Scopus, Web of Science, and Embase. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). The pooled results of 16 studies, including 5930 participants, showed that the association between TMAO levels and cancer incidence is insignificant (Odds Ratio: 0.97, 95% CI: (0.64, 1.46), P-value = 0.871). Subgroup analysis showed that urinary TMAO levels were negatively associated with cancer incidence; in contrast, a direct and positive association was observed between serum TMAO levels and cancer incidence. However, "gender" and the "TMAO measuring method" were the potential sources of discrepancies. Meta-regression analysis did not reveal any significant association between duration of studies, age, female ratio, subjects-control, and subjects-case. The present study demonstrates that serum TAMO levels were insignificantly associated with cancer incidence.

Senescence of bone marrow mesenchymal stem cells in Wistar male rats receiving normal chow/high-calorie diets with/without vitamin D.

Bone marrow mesenchymal stem cells (BM-MSCs) have a momentous function in the composition of the bone marrow microenvironment because of their many valuable properties and abilities, such as immunomodulation and hematopoiesis. The features and actions of MSCs are influenced by senescence, which may be affected by various factors such as nutritional/micronutrients status, e.g., vitamin D. This study aimed to examine the effects of a high-calorie diet (HCD) with/without vitamin D on BM-MSCs senescence. In the first phase, 48 middle-aged rats were fed a normal chow diet (NCD, n = 24) and an HCD (n = 24) for 26 weeks. Afterward, the rats in each group were randomly divided into three equal subgroups. Immediately, eight-rat from each diet group were sacrificed to assess the HCD effects on the first phase measurements. In the second phase, the remaining 4 groups of rats were fed either NCD or HCD with (6 IU/g) or without vitamin D (standard intake: 1 IU/g); in other words, in this phase, the animals were fed (a) NCD, (b) NCD plus vitamin D, (c) HCD, and (d) HCD plus vitamin D for 4 months. BM-MSCs were isolated and evaluated for P16INK4a, P38 MAPK, and Bmi-1 gene expression, reactive oxygen species (ROS) levels, SA-ß-gal activity, and cell cycle profile at the end of both phases. After 26 weeks (first phase), the ROS level, SA-ß-gal-positive cells, and cells in the G1 phase were significantly higher in HCD-fed rats than in NCD-fed ones (P < 0.05). HCD prescription did not significantly affect cells in the S and G2 phases (p > 0.05). Compared with the NCD-fed animals, P16INK4a and P38 MAPK gene expression were up-regulated in the HCD-fed animals; also, Bmi-1 gene expression was down-regulated (P < 0.05). BM-MSCs from vitamin D-treated rats (second phase) exhibited reduced mRNA levels of P16INK4a and P38 MAPK genes and increased Bmi-1 mRNA levels (all P < 0.05). Vitamin D prescription also declined the percentage of SA-ß-gal-positive cells, ROS levels, and the cells in the G1 phase and increased the cells in the S phase in both NCD and HCD-fed animals (P < 0.05). The reduction of the cells in the G2 phase in rats fed with an NCD plus vitamin D was statistically non-significant (P = 0.128) and significant in HCD plus vitamin D rats (P = 0.002). HCD accelerates BM-MSCs senescence, and vitamin D reduces BM-MSCs senescence biomarkers.

The effect of selenium supplementation on disease activity and immune-inflammatory biomarkers in patients with mild-to-moderate ulcerative colitis: a randomized, double-blind, placebo-controlled clinical trial.

PURPOSE: Selenium (Se) supplementation may help reduce inflammation and disease activity in ulcerative colitis (UC) patients. We investigated the therapeutic effects of Se administration in cases with mild-to-moderate active UC. METHODS: A multicenter, double-blind, randomized clinical trial (RCT) was conducted on 100 cases with active mild-to-moderate UC. The patients were randomly allocated to be given an oral selenomethionine capsule (200 mcg/day, n = 50) or a placebo capsule (n = 50) for 10 weeks. The primary outcome was defined as disease activity via the Simple Clinical Colitis Activity Index (SCCAI), and secondary outcomes were measured at the end of the study. RESULTS: After 10 weeks, the SCCAI score's mean was reduced in the Se group (P < 0.001). At the end of the intervention, clinical improvement (decline of 3 ≥ score from baseline score) was observed in 19 patients (38%) of the Se group and 3 patients (6%) of the placebo group. The patients with clinical remission (defined as SCCAI ≤ 2) were assigned in the Se group (P = 0.014). The Se group's quality of life and Se serum levels were enhanced at the end of the study (P < 0/001). In the Se group, the mean concentration of interleukin-17 decreased (P < 0/001). However, the levels of interleukin-10 showed no considerable change between the two groups in the 10th week (P = 0.23). CONCLUSION: Se supplementation as add-on therapy with medical management induced remission and improved the quality of life in patients with active mild-to-moderate UC. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: IRCT20091114002709N51; 2020-04-13.

A systematic review and meta-analysis of the omega-3 fatty acids effects on brain-derived neurotrophic factor (BDNF).

BACKGROUND: Omega-3 fatty acids (omega-3 FAs) have attracted the attention of researchers because of their influence on circulatory levels of brain-derived neurotrophic factor (BDNF). Our objective was to review systematically and Meta-analyze randomized controlled trials (RCTs) to assess the effects of omega-3 FAs supplementation on serum BDNF concentration. METHODS: Scopus, PubMed, Web of Science, and Cochrane Library were systematically searched until April 2023. The Cochrane risk of bias assessment tool was utilized to evaluate the quality of the studies. A random-effects model was employed to estimate the overall effect size of BDNF levels, using the Standard Mean Difference (SMD) and a 95% confidence interval (CI). The heterogeneity among the studies was assessed using chi-squared and I2 statistics. RESULTS: A total of 12 studies involving 587 subjects were included. The supplementation of PUFA was found to be associated with a significant increase in serum levels of BNDF in the group receiving the supplements, as compared to the placebo group (SMD: 0.72 pg/mL, 95% CI: 0.28, 1.15; P < 0.001) (I2 = 84.39%, P < 0.001). Sub-group analyses revealed similar findings in trials with fewer than 10 weeks, which utilized both animal (fish oil) and herbal (flaxseed) forms of omega-3 supplements with a high daily dosage of 2000mg. CONCLUSION: The present systematic review and meta-analysis indicate the efficacy of omega-3 FAs in increasing the serum concentration of BDNF. Therefore, omega-3 FAs should be prioritized as agents for increasing BDNF in interventions.

Dietary diversity score and cardio-metabolic risk factors: an updated systematic review and meta-analysis.

CONTEXT: Dietary diversity score (DDS) has been known as a useful and convenient indicator of overall diet quality. Previous studies have reported the association between DDS and health problems such as diabetes, metabolic syndrome and cardiovascular disease. OBJECTIVES: This systematic review and meta-analysis aimed to assess the association between dietary diversity score (DDS) and cardio-metabolic risk factors such as obesity and overweight, lipid profile, blood pressure, metabolic syndrome (MetS) and diabetes. DATA SOURCES: We systematically searched PubMed and NLM Gateway, Scopus and Institute of Scientific Information (ISI) by up to October 2019. DATA EXTRACTION: All observational studies which assessed the association of DDS with cardio-metabolic risk factors including anthropometric measures, blood pressure, lipid profile, glycemic indices and MetS without limitation in time of publication and language were included and critically reviewed by two independent experts. Random-effects meta-analysis was used to estimate the effect sizes. DATA ANALYSIS: Among 843 documents retrieved from literature search, 23 studies met the inclusion criteria for systematic review, and 18 studies were eligible for meta-analysis. Random-effects meta-analysis showed that the association of DDS with obesity, abdominal obesity, overweight, body mass index, MetS, diabetes, blood pressure, and lipid profile (TC, LDL, HDL) was not statistically significant. On the other hand, the association of DDS and TG was statistically significant (SMD: - 0.23, 95% CI - 0.45, - 0.01). CONCLUSIONS: Our findings revealed that there was no significant association between DDS and cardio-metabolic risk factors. Reassessment of the overall DDS tool as a criterion of diet quality and production of new and valid DDS standard tools is highly desirable. More high-quality studies are also needed to confirm the findings of this study. STUDY REGISTRATION: This study is registered as PROSPERO CRD42020157127. LEVEL OF EVIDENCE: Level I, systematic reviews and meta-analyses.

Effect of glutamine supplementation on cardiometabolic risk factors and inflammatory markers: a systematic review and meta-analysis.

BACKGROUND: Evidence exists that glutamine plays multiple roles in glucose metabolism, insulin sensitivity, and anti-inflammatory effects. This systematic review and meta-analysis of controlled trials aimed to assess the effect of glutamine supplementation on cardio-metabolic risk factors and inflammatory markers. METHODS: The processes of systematic reviews and meta-analyses were performed according to the PRISMA checklist. PubMed, Web of Sciences, Cochrane library, and Scopus databases were search for relevant studies without time or language restrictions up to December 30, 2020. All randomized clinical trials which assessed the effect of glutamine supplementation on "glycemic indices", "level of triglyceride, "and "inflammatory markers" were included in the study. The effect of glutamine supplementation on cardio-metabolic risk factors and inflammatory markers was assessed using a standardized mean difference (SMD) and 95% confidence interval (CI). Heterogeneity between among studies was assessed using Cochran Q-statistic and I-square. Random/fixed-effects meta-analysis method was used to estimate the pooled SMD. The risk of bias for the included trials was evaluated using the Cochrane quality assessment tool. RESULTS: In total, 12 studies that assessed the effect of glutamine supplementation on cardio-metabolic risk factors were included in the study. Meta-analysis showed that glutamine supplementation significantly decreased significantly serum levels of FPG [SMD: - 0.73, 95% CI - 1.35, - 0.11, I2: 84.1%] and CRP [SMD: - 0.58, 95% CI - 0.1, - 0.17, I2: 0%]. The effect of glutamine supplementation on other cardiometabolic risk factors was not statistically significant (P > 0.05). CONCLUSION: Our findings showed that glutamine supplementation might have a positive effect on FPG and CRP; both of which are crucial as cardio-metabolic risk factors. However, supplementation had no significant effect on other cardio-metabolic risk factors.

Effect of Selenium Supplementation on Lipid Profile: A Systematic Review and Meta-Analysis.

Selenium is an essential mineral that plays a key role in plenty of major metabolic processes. A growing body of literature has shown that selenium deficiency leads to an increase in plasma TC and TG levels. This study explores the effect of selenium supplementation on serum level of lipid profile [total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), very low density lipoprotein (VLDL)]. We systematically searched PubMed/MEDLINE, ISI/WOS, and Scopus (from their commencements to Jan 2016) to identify the papers investigating the association between the intake of selenium and lipid profile. Data extracted from the relevant studies were screened. The pooled standardized mean difference was estimated using the random or fixed effects model. Heterogeneity among the studies was assessed using Q-test. Of the potentially relevant articles screened, 11 articles including 1221 participants were included in this meta-analysis. Results of meta-analysis showed that intake of selenium resulted in a statistically significant improvement in TC, [(SMD): -0.13, 95% CI: (-0.24, -0.02)], TG [(SMD): -0.19, 95% CI: (-0.38, -0.01)] and VLDL [(SMD): -0.34, 95% CI: (-0.63, -0.05)]. The selenium supplementation did not significantly improve lipid profile such as LDL [(SMD): -0.08, 95% CI: (-0.036, 0.19)], HDL [(SMD): 0.01, 95% CI: (-0.164, 0.18)], HDL/TC ratio [(SMD): 0.025, 95% CI: (-0.11, 0.16)], non-HDL-C [(SMD): 0.018, 95% CI: (-0.13, 0.16)]. This meta-analysis suggests that the effect of selenium supplementation on the serum levels of TG and VLDL is marginally significant. However, the supplementation has no effect on other serum lipids. Moreover, the study shows that the effect of selenium supplementation on lipid profile is negative.

Effect of melatonin supplementation on cardiometabolic risk factors, oxidative stress and hormonal profile in PCOS patients: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: To investigate whether melatonin supplementation can enhance cardiometabolic risk factors, reduce oxidative stress, and improve hormonal and pregnancy-related factors in patients with PCOS. METHODS: We conducted a systematic search of PubMed/Medline, Scopus, and the Cochrane Library for articles published in English from inception to March 2023. We included randomized controlled trials (RCTs) on the use of melatonin for patients with polycystic ovary syndrome (PCOS). We performed a meta-analysis using a random-effects model and calculated the standardized mean differences (SMDs) and 95% confidence intervals (CIs). RESULTS: Six studies met the inclusion criteria. The result of meta-analysis indicated that melatonin intake significantly increase TAC levels (SMD: 0.87, 95% CI: 0.46, 1.28, I2 = 00.00%) and has no effect on FBS, insulin, HOMA-IR, TC, TG, HDL, LDL, MDA, hs-CRP, mFG, SHBG, total testosterone, and pregnancy rate in patients with PCOS compare to controls. The included trials did not report any adverse events. CONCLUSION: Melatonin is a potential antioxidant that may prevent damage from oxidative stress in patients with PCOS. However, the clear effect of melatonin supplementation on cardiometabolic risk factors, hormonal outcomes, and pregnancy-related outcomes needs to be evaluated further in large populations and long-term RCTs.

The Effect of Selenium, Zinc, and their Combined Supplementation on Cardiometabolic Biomarkers-comparing their Effects in the Energy Restriction and High-fat Diet Methods in Obese Rats.

INTRODUCTION: The fat distribution in the body determines the risk of cardiometabolic problems such as heart disease and diabetes. Some dietary supplements, such as selenium and zinc, possess lipolytic and anti-angiogenic functions, which may be a useful strategy in reducing the risk of cardiometabolic complications. This study evaluated the effect of zinc (Zn), selenium (Se), and their combined supplementation on cardiometabolic risk factors in male Wistar rats in two nutritional models, including caloric restriction (CR) and high-fat diet (HFD). METHODS AND MATERIALS: The 48 male Wistar rats were divided into three diet groups (HFD and CR and normal diet (ND)). The HFD group was subdivided into four groups (N=8 rats in each group) that received (HFD+Se), (HFD+Zn), (HFD+Zn+Se), and HFD alone as the control group, respectively. After 8 weeks of intervention, biochemical tests were performed on serum levels, including measurement of lipid profile (triglyceride, Cholesterol, LDL and HDL) and glycemic indices (fasting blood sugar, insulin and insulin sensitivity markers). RESULTS: The results showed that supplementation significantly improved the lipid profile (P <0.001). A comparison of glucose homeostasis indices in the study groups also showed a significant difference. The serum level of glucose was higher in the HFD group than in the intervention groups (P <0.001). Also, the rate of improvement of lipid profile and glycemic indexes in the group receiving the combination of two supplements showed a better trend than those receiving zinc and selenium alone. However, the values were statistically significant only for glucose homeostasis indices (P <0.001). CONCLUSION: Although obesity is a multifactorial condition, controlling other risk factors, zinc and selenium and their combined supplementation can lead to promising solutions for the treatment of obesity-induced glucose and lipid homeostasis disorders.

Association between Gut Microbiota Compositions with Microvascular Complications in Individuals with Diabetes: A Systematic Review.

BACKGROUND: Diabetes is one of the chronic and very complex diseases that can lead to microvascular complications. Recent evidence demonstrates that dysbiosis of the microbiota composition might result in low-grade, local, and systemic inflammation, which contributes directly to the development of diabetes mellitus and its microvascular consequences. OBJECTIVE: The aim of this systematic review was to investigate the association between diabetes microvascular complications, including retinopathy, neuropathy, nephropathy, and gut microbiota composition. METHODS: A systematic search was carried out in PubMed, Scopus, and ISI Web of Science from database inception to March 2023. Screening, data extraction, and quality assessment were performed by two independent authors. The Newcastle-Ottawa Quality Assessment Scale was used for quality assessment. RESULTS: About 19 articles were selected from 590 retrieved articles. Among the included studies, nephropathy has been studied more than other complications of diabetes, showing that the composition of the healthy microbiota is changed, and large quantities of uremic solutes that cause kidney injury are produced by gut microbes. Phyla, including Fusobacteria and Proteobacteria, accounted for the majority of the variation in gut microbiota between Type 2 diabetic patients with and without neuropathy. In cases with retinopathy, an increase in pathogenic and proinflammatory bacteria was observed. CONCLUSION: Our results revealed that increases in Bacteroidetes, proteobacteria and fusobacteria may be associated with the pathogenesis of diabetic nephropathy, neuropathy, and retinopathy. In view of the detrimental role of intestinal dysbiosis in the development of diabetes-related complications, gut microbiota assessment may be used as a biomarker in the future and interventions that modulate the composition of microbiota in individuals with diabetes can be used to prevent and control these complications.

The effect of quercetin supplementation on clinical outcomes in COVID-19 patients: A systematic review and meta-analysis.

Coronavirus disease (COVID-19) affects both the respiratory system and the body as a whole. Natural molecules, such as flavonoid quercetin, as potential treatment methods to help patients combat COVID-19. The aim of this systematic review and meta-analysis is to give a comprehensive overview of the impact of quercetin supplementation on inflammatory factors, hospital admission, and mortality of patients with COVID-19. The search has been conducted on PubMed, Scopus, Web of Science, EMBASE, and the Cochrane Library using relevant keywords until August 25, 2023. We included randomized controlled trials (RCTs) comparing COVID-19 patients who received quercetin supplementation versus controls. We included five studies summarizing the evidence in 544 patients. Meta-analysis showed that quercetin administration significantly reduced LDH activity (standard mean difference (SMD): -0.42, 95% CI: -0.82, -0.02, I 2 = 48.86%), decreased the risk of hospital admission by 70% (RR: 0.30, 95% CI: 0.14, 0.62, I 2 = 00.00%), ICU admission by 73% (RR: 0.27, 95% CI: 0.09, 0.78, I 2 = 20.66%), and mortality by 82% (RR: 0.18, 95% CI: 0.03, 0.98, I 2 = 00.00%). No significant changes in CRP, D-dimmer, and ferritin were found between groups. Quercetin was found to significantly reduce LDH levels and decrease the risk of hospital and ICU admission and mortality in patients with COVID-19 infection.

Protective Effect of Vitamin D Supplementation on Some Hemogram Derived Inflammatory Indices in Normal and High-Fat Diet Fed Male Wistar Rats.

Background: Hematological inflammatory indices are currently suggested to assess systemic inflammation. This study aims to investigate a vitamin D supplementation effect on hematological indices of inflammation in rats. Method: Forty-eight middle-aged male rats were allocated into a normal diet (ND) group (10% fat) and a high-fat diet (HFD) group (60% fat). The animals were fed for 26 weeks. After this period, each group was randomly divided into three subgroups, each of 8 rats: Group (1): animals were fed the ND and HFD containing 1 IU/g vitamin D for 4 months, group (2): animals were fed the ND and HFD containing 6 IU/g vitamin D for 4 months and group (3): animals were euthanized to evaluate the HFD effect. Serum 25-hydroxyvitamin D level, white blood cell count (WBCs), platelet count, platelet crit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR) were measured. Results: The HFD, significantly increased body weight, PCT, PDW, PLR, NLR, and MLR and significantly reduced serum vitamin D levels compared to the ND (P < 0.05). There was a significant decrease in food intake, MPV, PDW, and NLR after vitamin D supplementation in the ND-fed group (P < 0.05). A significant reduction in platelet count, PCT, and MLR was observed after vitamin D supplementation in HFD-fed rats (P < 0.05). Conclusions: In our study, some hemogram-derived inflammatory indices were higher in the HFD-fed group, and vitamin D supplementation lowering effects on some hematological indices were seen in both ND and HFD groups.

Muscle Strength and Biochemical Markers as Predictors of Depression in Hemodialysis Patients: A Cross-Sectional Study.

Patients with chronic renal failure, many of which treated with hemodialysis, present a high prevalence of impaired muscle strength which suggest that muscle mass parameters may be used as markers for changes in muscle in these patients. Measurement of handgrip strength (HGS) is a common, simple, and quick measure of muscle function an indicator of overall muscle strength which has been associated with physical activity and several anthropometric traits. Intercellular adhesion molecule-1 (ICAM-1) and insulin-like growth factor-1 (IGF-1) are biochemical markers associated with inflammatory processes which are a common consequence of dialysis. Additionally, hemodialysis patients frequently present signs of malnutrition and depression. This cross-sectional study aimed to evaluate if muscle and biochemical markers could be used to predict the risk of depression in hemodialysis patients. Several anthropometric parameters, nutrient intake, depression state and the serum levels of ICAM-1 and IGF-1 were determined and Pearson's correlation coefficient and/or Spearman's correlation coefficient were used to test the correlation between them. Our results do not show a correlation between HGF, IGF-1 and ICAM-1 with the depression status of the patients, but mid-arm muscle circumference (MAMC) was statistically and positively correlated with depression. Additionally, ICAM-1 levels were negatively correlated with HGS, MAMC, and IGF-1. Overall, the results of the present study suggest that HGS may be used as an indicator of cardiovascular diseases and MAMC may be a good predictor of the level of depression in hemodialysis patients, although further studies are required.

The Effect of Zinc Supplementation on Circulating Levels of Brain-Derived Neurotrophic Factor (BDNF): A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: There are randomized controlled trials (RCTs) about the zinc supplementation effect on circulating levels of brain-derived neurotrophic factor (BDNF). However, the findings of these studies are inconsistent. The purpose of this systematic review and meta-analysis was to determine the zinc supplementation effect on BDNF and zinc levels in published RCTs. Methods: We searched PubMed/Medline, Cochrane, Scopus, ISI Web of Science, EMBASE, "Clinicaltrials.gov", "Cochrane Register of Controlled Trials", "IRCT" and also key journals up to 2019. RCTs with two intervention (zinc) and control (placebo) groups that evaluated zinc supplementation efficacy on BDNF levels were included. Study heterogeneity was assessed, and then, meta-analysis was performed using the fixed-effects model. Results: Four studies were included in the present secondary analysis. Compared with placebo, zinc supplementation significantly enhanced circulating levels of BDNF [(SMD): 0.31, 95% confidence interval (CI): (0.22, 0.61)] and zinc [(SMD): 0.88, 95% CI: (0.54, 1.22)] with no considerable heterogeneity among the studies [(Q = 3.46; P = 0.32; I2% = 13.4); (Q = 2.01; P = 0, 37; I2% = 0.5), respectively]. Conclusions: Our results propose that zinc supplementation can increase the circulating levels of BDNF and zinc. This study was registered at PROSPERO as CRD42020149513.

Effects of Vitamin D Supplementation on Bone Health and Bone-related Parameters in HIV-infected Patients: A Systematic Review and Meta-analysis.

PURPOSE: There is growing evidence that bone health is decreased in individuals with HIV infection. Vitamin D deficiency is also highly prevalent among HIV-infected patients. The literature was systematically reviewed to determine whether bone health and bone-related parameters may improve with vitamin D supplementation in HIV-infected individuals. METHODS: Four databases were systematically searched for randomized clinical trials of vitamin D supplementation in HIV infection, published from January 1990 to September 2021. No language or publication restrictions were applied. Standardized mean differences (SMD) with 95% CIs are reported. A random-effects model was used to perform meta-analysis. FINDINGS: Ten studies met the inclusion criteria (N = 733 participants at study completion). The mean ages of the patients in the included trials ranged from 10 to 49 years. The meta-analysis indicated that with vitamin D supplementation, serum 25-hydroxy vitamin D (25[OH]D) level was significantly increased (SMD, 1.86; 95% CI, 1.02 to 2.70; I2 = 94.4%), but there were no significant effects on levels of serum 1,25-dihydroxy vitamin D (1,25-[OH]2D) (SMD, 0.29; 95% CI, -0.07 to 0.64; I2 = 67.4%), total bone mineral density (SMD, 0.07; 95% CI, -0.23 to 0.37; I2 = 00.0%), spine bone mineral density (SMD, 0.15; 95% CI, -0.19 to 0.49; I2 = 17.3%), and parathyroid hormone level (SMD, -0.18; 95% CI, -0.37 to 0.02; I2 = 1.2%) in HIV-infected patients. IMPLICATIONS: This study showed that vitamin D supplementation can improve serum 25(OH)D in HIV-infected patients. The effects of vitamin D supplementation on other bone health-related parameters such as bone mineral density and parathyroid hormone in HIV-infected patients need to be further investigated in larger-scale, well-designed randomized, controlled trials.

Beneficial effects of Se/Zn co-supplementation on body weight and adipose tissue inflammation in high-fat diet-induced obese rats.

This research investigated the effect of co-supplementation of selenium with zinc on weight control and the inflammatory and oxidative status in relation to obesity. Male Wistar rats (N = 32) were randomly divided into four groups after induction of obesity model: 1) "Zn" was supplemented with zinc sulfate (15 mg/kg BW), 2) "Se" supplemented with selenium as sodium selenate (0.5 mg/kg BW), 3) "Zn + Se" which received Zn (15 mg/kg BW) + Se (0.5 mg/kg BW), and 4) "HFD" as the control group. The intervention was done for eight weeks. At the end of treatment, serum and tissue level of Zn, Se, SOD, GSH-Px, MDA, leptin, TNF-α, and IL-6 was evaluated. Weight and food intake were significantly reduced in the Se group(p < .001), while in the Zn group, weight gain due to obesity was prevented compared to the control group (p = .48). There was a significant and stronger increase in SOD, GSH-Px levels and a remarkable decrease in MDA, leptin, TNF-α, and IL-6 in the group receiving the combination of two supplements than either alone(p < .001). Leptin had a positive correlation with inflammatory factors and lipid peroxidation marker and showed an inverse relationship with Zn and Se levels and anti-oxidative enzymes(p < .05). The analysis showed the mediating role of leptin in the effects of zinc. Co-supplementation of selenium and zinc may have a synergistic effect in reduction of oxidative and inflammatory markers. Regarding the effect of zinc on inflammatory factors and lipid peroxidation, leptin can play a mediating role.

Validity of continuous metabolic syndrome score for predicting metabolic syndrome; a systematic review and meta-analysis.

BACKGROUND: Nowadays, use of continuous metabolic syndrome (cMetS) score has been suggested to improve recognition of metabolic syndrome (MetS). The aim of this study was to evaluate the validity of cMetS scores for predicting MetS. METHODS: We searched the electronic databases included MEDLINE/PubMed, Embase, ISI Web of Science, and Scopus from 1 January 1980 to 30 September 2020. Observational studies on participants with different cMetS scores were included in this meta-analysis. The sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR) and diagnostic odds ratio (DOR) with 95% CI were calculated. RESULTS: Ten studies involving a total of 25,073 participants were included. All studies had cross-sectional design. The pooled sensitivity and specificity of cMetS scores for predicting MetS were 0.90 (95% CI: 0.83 to 0.95) and 0.86 (95% CI: 0.83 to 0.89), respectively. Moreover, cMetS scores had the pooled LR+ of 6.5 (95% CI: 5.0 to 8.6), and a pooled (LR-) of 0.11 (95% CI: 0.063 to 0.21). The pooled DOR of cMetS scores to predict MetS were 57 (95% CI: 26 to 127). CONCLUSIONS: The high sensitivity and specificity of cMetS scores indicates that it has a high accuracy to predict the risk of MetS. Furthermore, the cMetS scores has a good ability to rule out healthy people. STUDY REGISTRATION: This study was registered as PROSPERO CRD42020157273.