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1.
Serum Trace Elements in Patients With Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis.
Yin, J, Hong, X, Ma, J, Bu, Y, Liu, R
Frontiers in endocrinology. 2020;:572384
Abstract
Polycystic ovary syndrome (PCOS) is reported to be associated with certain trace elements. However, previous data are inconsistent and potentially biased due to small sample sizes. The potential utility of trace element levels for screening of PCOS remains to be established. The aim of this meta-analysis was to investigate the potential relationships between PCOS and serum levels of zinc (Zn), copper (Cu), magnesium (Mg), iron (Fe) and ferritin. We carried out a literature search of PubMed, EMBASE, and Web of Science for relevant cross-sectional/case-control studies published prior to October 2019. Random-effect models were used to estimate the overall standard mean differences (SMDs) between PCOS and healthy control subjects. The screening value of potential microelement biomarkers for PCOS was assessed using the receiver operating characteristic (ROC) curve. Twenty-one studies featuring 2,173 women with PCOS and 1,897 healthy women were selected for analysis. Our results showed that Cu and ferritin levels were significantly higher in women with PCOS than healthy controls, with SMDs of 0.52 [95% confidence interval (CI): 0.38-0.67, I2 = 47.6%] and 1.05 (95% CI: 0.25-1.86, I2 = 97.0%), respectively. The serum ferritin concentration was distinguished as a potential biomarker for PCOS based on the high area under ROC curve value of 0.71 (95% CI: 0.57-0.86). Although we did not identify a statistical association between serum Zn concentration and PCOS overall, the concentration of Zn in PCOS women with insulin resistance (IR) was lower than that in healthy women (SMD = -0.89, 95% CI: -1.73 to -0.06). Furthermore, the concentrations of Mg (SMD = 0.31, 95% CI: -0.32-0.94, I2 = 95.4%) and Fe (SMD = -0.59, 95% CI: -1.29-0.12, I2 = 97.2%) were not statistically significant between the PCOS and control groups. We generated hypothetical pathways for associations among serum Cu, ferritin and PCOS. The serum concentrations of both Cu and ferritin were significantly higher in women with PCOS, and ferritin was identified as a potential early indicator for PCOS screening. Further studies are essential to determine the specific underlying mechanisms.
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2.
Beyond the Mind-Serum Trace Element Levels in Schizophrenic Patients: A Systematic Review.
Baj, J, Forma, A, Sitarz, E, Karakuła, K, Flieger, W, Sitarz, M, Grochowski, C, Maciejewski, R, Karakula-Juchnowicz, H
International journal of molecular sciences. 2020;(24)
Abstract
The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum disorder, or major depressive disorder. The fluctuations in the trace element concentrations might act as potential diagnostic and prognostic biomarkers of many psychiatric and neurological disorders. This paper aimed to assess the alterations in serum trace element concentrations in patients with a diagnosed schizophrenia. The authors made a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 5009 articles identified through database searching, 59 of them were assessed for eligibility. Ultimately, 33 articles were included in the qualitative synthesis. This review includes the analysis of serum levels of the following trace elements: iron, nickel, molybdenum, phosphorus, lead, chromium, antimony, uranium, magnesium, aluminum, zinc, copper, selenium, calcium, and manganese. Currently, there is no consistency regarding serum trace element levels in schizophrenic patients. Thus, it cannot be considered as a reliable prognostic or diagnostic marker of schizophrenia. However, it can be assumed that altered concentrations of those elements are crucial regarding the onset and exaggeration of either psychotic or negative symptoms or cognitive dysfunctions.
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3.
Zinc supplementation for the promotion of growth and prevention of infections in infants less than six months of age.
Lassi, ZS, Kurji, J, Oliveira, CS, Moin, A, Bhutta, ZA
The Cochrane database of systematic reviews. 2020;(4):CD010205
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Abstract
BACKGROUND Zinc is a vital micronutrient for humans and is essential for protein synthesis, cell growth, and differentiation. Severe zinc deficiency can lead to slower physical, cognitive and sexual growth, cause skin disorders, decrease immunity, increase incidence of acute illnesses in infants and children and contribute to childhood stunting. By estimation, 17.3% of the world population is at risk of inadequate zinc intake. Such nutritional impairment increases the risk of diarrhoea and pneumonia by 20%, as well as leads to a global loss of more than 16 million disability-adjusted life years in children less than five years of age. Not only does zinc deficiency affect lives, it adds to the considerable financial burden on depleted resources in countries that are most affected. By preventing or curing this deficiency, we can improve childhood mortality, morbidity and growth. OBJECTIVES To assess the effectiveness of zinc supplementation for the promotion of growth, reduction in mortality, and the prevention of infections in infants less than six months of age. SEARCH METHODS We used the standard search strategy of the Cochrane Neonatal Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 4), MEDLINE via PubMed (1966 to 18 May 2018), Embase (1980 to 18 May 2018), and CINAHL (1982 to 18 May 2018). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. An updated search from 1 January 2018 to 29 January 2020 was run in the following databases: CENTRAL via CRS Web, MEDLINE via Ovid, and CINAHL via EBSCOhost. SELECTION CRITERIA All randomised controlled (individual and cluster randomised) and quasi-randomised trials of zinc supplementation in healthy, term infants, less than six months of age comparing infant mortality, incidence of diarrhoea or respiratory illnesses, growth and/or serum zinc levels were eligible. DATA COLLECTION AND ANALYSIS Two review authors screened search results (title and abstracts) and relevant full texts. Studies fulfilling prespecified inclusion criteria were included with any disagreements resolved by consensus. Extraction and analysis were then conducted. We used the GRADE approach to assess the quality of evidence as indicated by certainty in effect estimates. MAIN RESULTS Eight studies (with 85,629 infants) were included and five studies were meta-analysed, out of which four studies compared zinc with placebo, and one compared zinc plus riboflavin versus riboflavin. Certain growth outcomes after six months of intervention (Weight for Age Z-scores (WAZ) (standardised mean difference) (SMD) 0.16, 95% CI 0.03 to 0.29; three studies, n = 955; fixed-effect; heterogeneity Chi² P = 0.96); I² = 0%); change in WAZ (SMD 0.16, 95% CI 0.07 to 0.25; one study, n = 386; fixed-effect); (Weight-for-Length Z-score (WLZ) (SMD 0.15, 95% CI 0.02 to 0.28; three studies, n = 955; fixed-effect; heterogeneity: Chi² P = 0.81); I² = 0%); (change in WLZ (SMD 0.17, 95% CI 0.06 to 0.28; one study, n = 386; fixed-effect)) were positively affected by zinc supplementation compared to placebo. A single study reported no difference in the incidence of diarrhoea and lower respiratory tract infection with zinc supplementation. Zinc had no effect on mortality in children younger than 12 months. When zinc plus riboflavin was compared to riboflavin only, significant improvement was observed in the incidence of wasting at 24 months (risk ratio (RR) 0.59, 95% CI 0.37 to 0.96; one study, n = 296; fixed-effect), but significant worsening of incidence of stunting was present at 21 months (RR 1.53, 95% CI 1.09 to 2.16; one study, n = 298; fixed-effect). AUTHORS' CONCLUSIONS There was a significant positive impact of zinc supplementation on WAZ and WLZ after six months of intervention in infants compared to placebo. When a combined supplement of zinc and riboflavin was compared to riboflavin, there was a significant reduction in wasting at 24 months, but stunting at 21 months was negatively affected. Although included trials were of good-to-moderate quality, evidence that could be meta-analysed was based on a few studies which affected the overall quality of results. Regardless, there is a need for strong trials conducted in infants younger than six months before a strong recommendation can be made supporting zinc supplementation in this age group.
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Role of zinc supplementation in the management of chronic liver diseases: A systematic review and meta-analysis.
Diglio, DC, Fernandes, SA, Stein, J, Azeredo-da-Silva, A, de Mattos, AA, Tovo, CV
Annals of hepatology. 2020;(2):190-196
Abstract
INTRODUCTION AND OBJECTIVES Zinc deficiency has been associated with poor prognosis in chronic liver disease. This systematic review and meta-analysis aimed to evaluate the role of zinc supplementation in the management of chronic liver diseases. MATERIALS AND METHODS We searched MEDLINE, LILACS, EMBASE, and Cochrane CENTRAL databases from inception to August 2018. We included randomized controlled trials evaluating adult patients with chronic liver disease of any etiology receiving zinc supplementation. Studies with other designs or evaluating chronic conditions other than liver disease were excluded. Two reviewers independently screened and extracted data from eligible studies. Study quality was assessed using the Cochrane Collaboration's tool for assessing risk of bias in randomized studies. RESULTS Of 1315 studies screened, 13 were included. Six assessed chronic hepatitis C treatment, with a relative risk of 0.83 indicating no protective effect of zinc supplementation on the improvement of sustained virological response. Three evaluated response to hepatic encephalopathy treatment, with a relative risk of 0.66 indicating a favorable effect of zinc supplementation on clinical improvement of this condition. Of four studies evaluating the management of cirrhosis, two analyzed the effect of zinc supplementation on serum albumin levels, with no statistical difference between zinc and placebo groups. CONCLUSIONS Clinical trials assessing zinc supplementation in liver diseases do not show benefits in terms of clinical improvement or disease halting. There are possible benefits of zinc supplementation on hepatic encephalopathy, however, this is based on limited evidence. This research question is still open for evaluation in larger, well-designed, clinical trials.
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Trace Elements Homeostatic Imbalance in Psoriasis: a Meta-Analysis.
Chen, W, Zhou, X, Zhu, W
Biological trace element research. 2019;(2):313-322
Abstract
Studies point out that trace elements take vital roles in immunological and inflammatory reactions, such as psoriasis, while the conclusions are controversial. The purpose of this study was to analyze the existing literatures and explore the relationship between the risk of psoriasis and four trace elements zinc (Zn), copper (Cu), iron (Fe), and selenium (Se). We identified 42 studies through the databases PubMed, Embase, Cochrane Library, Google Scholar, and Web of knowledge. After the meta-analysis, the serum zinc, iron, and selenium levels showed no remarkable difference between psoriasis and controls. The people with psoriasis showed a higher level of zinc in lesion tissue (standard mean difference (SMD) = 14.43; 95% confidence interval (CI), 7.89-20.97; P < 0.0001), and a higher level of serum copper than controls (SMD = 18.23; 95% CI, 5.06-31.40; P = 0.007). Our findings indicated that the trace element of copper and zinc levels are in a homeostatic imbalance in psoriasis patients when compared with controls, which raise the question whether this imbalance can be taken as the therapy target for psoriasis.
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Quantifying the association between acute leukemia and serum zinc, copper, and selenium: a meta-analysis.
Kim, S, Freeland-Graves, JH, Babaei, M, Sachdev, PK, Beretvas, SN
Leukemia & lymphoma. 2019;(6):1548-1556
Abstract
Acute leukemia is a clonal malignant disorder that occurs when immature blast cells accumulate in bone marrow. Zinc (Zn) and copper (Cu) are related to normal lymphocyte maturation and immune function regulation. Selenium (Se) is protective against oxidative damage. The aim of this meta-analysis is to statistically synthesize results from studies that have investigated the levels of Zn, Cu, and Se in acute leukemia patients. The effect size, delta, was used to standardize the raw data. The robust variance estimation (RVE) method was performed to measure the pooled effect size and variance. Results suggest significant negative differences for levels of serum Zn (p < .05, delta = -1.21; 95% CI, -2.13--0.28) and Se (p < .05, delta = -1.84; 95% CI, -3.39--0.29) and significantly positive differences between serum Cu levels (p < .01, delta = 1.94; 95% CI, 1.02-2.87) in acute leukemia, as compared to the controls.
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Efficacy of zinc supplementation for neonatal sepsis: a systematic review and meta-analysis.
Tang, Z, Wei, Z, Wen, F, Wu, Y
The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2019;(7):1213-1218
Abstract
Background: Zinc supplementation has some potential in treating neonatal sepsis. We conduct a systematic review and meta-analysis to explore the efficacy of zinc supplementation for neonatal sepsis. Methods: PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases are systematically searched. Randomized controlled trials (RCTs) assessing the efficacy of zinc supplementation in neonatal sepsis are included. Two investigators independently search articles, extract the data, and assessed the quality of included studies. Meta-analysis is performed using the random-effect model. Results: Four RCTs involving 986 patients are included in the meta-analysis. Overall, compared with control intervention in neonatal sepsis, zinc supplementation is able to significantly reduce mortality rate (risk ratio (RR) = 0.48; 95% confidence intervals (CIs) = 0.25-0.94; p = .03) and improve serum zinc (mean difference (MD) = 81.97; 95% CI = 34.57-129.37; p = .0007), but has no remarkable influence on hospital stay (MD = -4.51; 95% CI = -15.08 to 6.05; p = .40) and the number of expired patients (RR = 0.63; 95% CI = 0.24-1.65; p = .35). Conclusions: Zinc supplementation may significantly reduce mortality rate and improve serum zinc in neonatal sepsis, but has no substantial influence on hospital stay and the number of expired patients.
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Common trace metals in rheumatoid arthritis: A systematic review and meta-analysis.
Ma, Y, Zhang, X, Fan, D, Xia, Q, Wang, M, Pan, F
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2019;:81-89
Abstract
INTRODUCTION Environmental risk factors regrading rheumatoid arthritis (RA) have not been explored extensively. Selenium (Se), zinc (Zn) and copper (Cu) nutrients were reported to associate with RA, but the results were inconsistent. Therefore, we conduct present study to meta-analyze the relationship between serum Se, Zn and Cu and RA and review the potential mechanisms. METHODS PubMed, Web of Science and Cochrane Library were comprehensively searched till October 1, 2018 for pertinent studies. Standard mean differences (SMDs) and 95% confident intervals (CIs) were calculated according to random effects model. RESULTS Finally 41 literatures were included. Meta-analysis of 16 studies involving 806 RA patients and 959 health controls showed that serum Se (SMD = -1.04, 95% CI = -1.58 to -0.50) was decreased in RA patients, and 23 literatures with 1398 patients and 1299 controls reported serum Zn (SMD = -1.20, 95% CI = -1.74 to -0.67) was decreased. But serum Cu (SMD = 1.26, 95% CI = 0.63 to -1.89) was increased with 26 studies including 1723 patients and 1451 controls. Meta-regression reported that steroid use was positively related to serum level of Se in RA (β = 0.041, 95% CI = 0.002 to 0.079). Differences in serum Se, Zn and Cu between rheumatoid arthritis patients and controls were all related with the geographical distribution. CONCLUSIONS Patients with RA have significant decreased serum Se and Zn and increased serum Cu than health controls, suggesting potential roles of Se, Zn and Cu in the pathogenesis of RA. Patients and rheumatologist should give enough attention to the monitor of these elements during follow up.
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Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment.
McCleery, J, Abraham, RP, Denton, DA, Rutjes, AW, Chong, LY, Al-Assaf, AS, Griffith, DJ, Rafeeq, S, Yaman, H, Malik, MA, et al
The Cochrane database of systematic reviews. 2018;(11):CD011905
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Abstract
BACKGROUND Vitamins and minerals have many functions in the nervous system which are important for brain health. It has been suggested that various different vitamin and mineral supplements might be useful in maintaining cognitive function and delaying the onset of dementia. In this review, we sought to examine the evidence for this in people who already had mild cognitive impairment (MCI). OBJECTIVES To evaluate the effects of vitamin and mineral supplementation on cognitive function and the incidence of dementia in people with mild cognitive impairment. SEARCH METHODS We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CENTRAL, CINAHL, LILACs, Web of Science Core Collection, ClinicalTrials.gov, and the WHO Portal/ICTRP, from inception to 25 January 2018. SELECTION CRITERIA We included randomised or quasi-randomised, placebo-controlled trials which evaluated orally administered vitamin or mineral supplements in participants with a diagnosis of mild cognitive impairment and which assessed the incidence of dementia or cognitive outcomes, or both. We were interested in studies applicable to the general population of older people and therefore excluded studies in which participants had severe vitamin or mineral deficiencies. DATA COLLECTION AND ANALYSIS We sought data on our primary outcomes of dementia incidence and overall cognitive function and on secondary outcomes of episodic memory, executive function, speed of processing, quality of life, functional performance, clinical global impression, adverse events, and mortality. We conducted data collection and analysis according to standard Cochrane systematic review methods. We assessed the risk of bias of included studies using the Cochrane 'Risk of bias' assessment tool. We grouped vitamins and minerals according to their putative mechanism of action and, where we considered it to be clinically appropriate, we pooled data using random-effects methods. We used GRADE methods to assess the overall quality of evidence for each comparison and outcome. MAIN RESULTS We included five trials with 879 participants which investigated B vitamin supplements. In four trials, the intervention was a combination of vitamins B6, B12, and folic acid; in one, it was folic acid only. Doses varied. We considered there to be some risks of performance and attrition bias and of selective outcome reporting among these trials. Our primary efficacy outcomes were the incidence of dementia and scores on measures of overall cognitive function. None of the trials reported the incidence of dementia and the evidence on overall cognitive function was of very low-quality. There was probably little or no effect of B vitamins taken for six to 24 months on episodic memory, executive function, speed of processing, or quality of life. The evidence on our other secondary clinical outcomes, including harms, was very sparse or very low-quality. There was evidence from one study that there may be a slower rate of brain atrophy over two years in participants taking B vitamins. The same study reported subgroup analyses based on the level of serum homocysteine (tHcy) at baseline and found evidence that B vitamins may improve episodic memory in those with tHcy above the median at baseline.We included one trial (n = 516) of vitamin E supplementation. Vitamin E was given as 1000 IU of alpha-tocopherol twice daily. We considered this trial to be at risk of attrition and selective reporting bias. There was probably no effect of vitamin E on the probability of progression from MCI to Alzheimer's dementia over three years (HR 1.02; 95% CI 0.74 to 1.41; n = 516; 1 study, moderate-quality evidence). There was also no evidence of an effect at intermediate time points. The available data did not allow us to conduct analyses, but the authors reported no significant effect of three years of supplementation with vitamin E on overall cognitive function, episodic memory, speed of processing, clinical global impression, functional performance, adverse events, or mortality (five deaths in each group). We considered this to be low-quality evidence.We included one trial (n = 256) of combined vitamin E and vitamin C supplementation and one trial (n = 26) of supplementation with chromium picolinate. In both cases, there was a single eligible cognitive outcome, but we considered the evidence to be very low-quality and so could not be sure of any effects. AUTHORS' CONCLUSIONS The evidence on vitamin and mineral supplements as treatments for MCI is very limited. Three years of treatment with high-dose vitamin E probably does not reduce the risk of progression to dementia, but we have no data on this outcome for other supplements. Only B vitamins have been assessed in more than one RCT. There is no evidence for beneficial effects on cognition of supplementation with B vitamins for six to 24 months. Evidence from a single study of a reduced rate of brain atrophy in participants taking vitamin B and a beneficial effect of vitamin B on episodic memory in those with higher tHcy at baseline warrants attempted replication.
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Chromium supplementation in women with polycystic ovary syndrome: Systematic review and meta-analysis.
Tang, XL, Sun, Z, Gong, L
The journal of obstetrics and gynaecology research. 2018;(1):134-143
Abstract
AIM: Increasing evidence has suggested that chromium supplementation may improve the clinical symptoms of polycystic ovary syndrome (PCOS), yet the results have been inconsistent. To derive a more precise estimation of the efficacy of chromium, a meta-analysis was performed. METHODS Studies published in PubMed, EMBASE and the Cochrane Library up to April 2017 were retrieved. Standardized mean differences (SMD) with 95%CI were calculated for net changes using random-effects or fixed-effects models. RESULTS A total of six randomized clinical trials (RCT) with 351 PCOS women were ultimately collected in this meta-analysis. All included RCT were of moderate-high quality. On pooled analysis, insulin resistance was significantly decreased (SMD, -0.84; 95%CI: -1.30 to -0.38; P = 0.0004), while the total testosterone (SMD, 0.36; 95%CI: 0.07-0.65; P = 0.02) and free testosterone (SMD, 0.80; 95%CI: 0.48-1.12; P < 0.00001) were markedly increased in chromium-treated PCOS patients compared with control groups. No significant difference was found in other indexes of insulin metabolism (body mass index, fasting insulin, fasting blood sugar and quantitative insulin sensitivity check index), hormone status (luteinizing hormone, follicle-stimulating hormone and prolactin) and lipid profiles (cholesterol and triglycerides) between the two groups. CONCLUSION Supplementation with chromium may not have significant benefits for women with PCOS. More RCT with low heterogeneity, however, are required to corroborate the present findings.