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The Cochrane Database of Systematic... Apr 2020Zinc is a vital micronutrient for humans and is essential for protein synthesis, cell growth, and differentiation. Severe zinc deficiency can lead to slower physical,... (Meta-Analysis)
Meta-Analysis
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.
Topics: Body Weight; Growth; Humans; Infant; Infant Mortality; Infant, Newborn; Infection Control; Randomized Controlled Trials as Topic; Riboflavin; Trace Elements; Vitamin B Complex; Wasting Syndrome; Zinc
PubMed: 32266964
DOI: 10.1002/14651858.CD010205.pub2 -
Clinical Breast Cancer Aug 2020Epidemiologic studies focusing on the association between 1-carbon metabolism-related vitamins (ie, folate, vitamin B, vitamin B, vitamin B) and breast cancer risk have... (Meta-Analysis)
Meta-Analysis
Epidemiologic studies focusing on the association between 1-carbon metabolism-related vitamins (ie, folate, vitamin B, vitamin B, vitamin B) and breast cancer risk have reported inconsistent findings. We conducted a systematic search of the reported data and performed a meta-analysis of prospective case-control and cohort studies to derive a more precise evaluation. The PubMed and EMBASE databases were searched to identify eligible studies. A total of 27 studies involving 49,707 cases and 1,274,060 individuals were included in the meta-analysis. The results indicated that a high intake of folate, vitamin B, and vitamin B might decrease the risk of breast cancer. The corresponding pooled relative risks (RRs) for the highest intake compared with the lowest were 0.93 (95% confidence interval [CI], 0.88-0.99; P = .018), 0.94 (95% CI, 0.89-1.00; P = .037) and 0.90 (95% CI, 0.82-0.99; P = .026). No significant association between vitamin B and breast cancer risk was found (RR, 0.99; 95% CI, 0.94-1.04; P = .604). Further study showed that folate and vitamin B might decrease the risk of estrogen receptor-negative (ER)/progesterone receptor-negative (PR) breast cancer but not ER/PR breast cancer. The dose-response meta-analysis indicated a significant linearity relationship between folate intake and a reduced risk of ER/PR breast cancer. An increment of folate intake (100 μg/d) corresponded to a 7% deceased risk of ER/PR breast cancer (RR, 0.93; 95% CI, 0.89-0.98; P = .007). In conclusion, a high intake of 1-carbon metabolism-related vitamins might contribute to the prevention of breast cancer, especially ER/PR breast cancer.
Topics: Breast; Breast Neoplasms; Case-Control Studies; Diet Surveys; Female; Folic Acid; Humans; Prospective Studies; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Riboflavin; Risk Assessment; Risk Factors; Vitamin B 12; Vitamin B 6
PubMed: 32241696
DOI: 10.1016/j.clbc.2020.02.012 -
Components of one-carbon metabolism and renal cell carcinoma: a systematic review and meta-analysis.European Journal of Nutrition Dec 2020Little is known about the aetiology of renal cell carcinoma (RCC). Components of one-carbon (1C) metabolism, which are required for nucleotide synthesis and methylation... (Meta-Analysis)
Meta-Analysis
PURPOSE
Little is known about the aetiology of renal cell carcinoma (RCC). Components of one-carbon (1C) metabolism, which are required for nucleotide synthesis and methylation reactions, may be related to risk of RCC but existing evidence is inconclusive. We conducted a systematic review and independent exposure-specific meta-analyses of dietary intake and circulating biomarkers of 1C metabolites and RCC risk.
METHODS
Medline and Embase databases were searched for observational studies investigating RCC or kidney cancer incidence or mortality in relation to components of 1C metabolism and 12 eligible articles were included in the meta-analyses. We used Bayesian meta-analyses to estimate summary relative risks (RRs) and 95% credible intervals (CrIs) comparing the highest versus lowest categories as well as the between-study heterogeneity.
RESULTS
We did not find convincing evidence of an association between any exposure (riboflavin, vitamin B, folate, vitamin B, methionine, homocysteine, choline, or betaine) and RCC risk. However, vitamin B biomarker status did have a protective (RR = 0.62) but imprecise (95% CrI 0.39-1.14) effect estimate and folate intake had a notable association as well (RR = 0.85, 95% CrI 0.71-1.01).
CONCLUSION
There was a lack of precision due largely to the low number of studies. Further investigation is warranted, especially for folate and vitamin B, which had consistent suggestive evidence of a protective effect for both dietary intake and biomarker status. A unique strength of this review is the use of Bayesian meta-analyses which allowed for robust estimation of between-study heterogeneity.
Topics: Bayes Theorem; Carbon; Carcinoma, Renal Cell; Folic Acid; Humans; Kidney Neoplasms; Risk Factors; Vitamin B 12; Vitamin B 6
PubMed: 32162043
DOI: 10.1007/s00394-020-02211-6 -
Nutrients Jan 2020Obesity is associated with reduced gut microbial diversity and a high rate of micronutrient deficiency. Bariatric surgery, the therapy of choice for severe obesity,...
Obesity is associated with reduced gut microbial diversity and a high rate of micronutrient deficiency. Bariatric surgery, the therapy of choice for severe obesity, produces sustained weight loss and improvements in obesity-related comorbidities. Also, it significantly alters the gut microbiota (GM) composition and function, which might have an important impact on the micronutrient status as GM is able to synthesize certain vitamins, such as riboflavin, folate, B, or vitamin K. However, recent data have reported that GM is not fully restored after bariatric surgery; therefore, manipulation of GM through probiotics represents a promising therapeutic approach in bariatric patients. In this review, we discuss the latest evidence concerning the relationship between obesity, GM and micronutrients, the impact of bariatric surgery on GM in relation with micronutrients equilibrium, and the importance of the probiotics' supplementation in obese patients submitted to surgical treatment.
Topics: Animals; Bariatric Surgery; Gastrointestinal Microbiome; Humans; Micronutrients; Nutritional Status; Obesity; Probiotics; Treatment Outcome
PubMed: 31963247
DOI: 10.3390/nu12010235 -
Journal of Cutaneous Medicine and... 2020Hidradenitis suppurativa (HS) is a common inflammatory disorder characterized by recurrent, painful, and malodorous abscesses and nodules predominantly in skin folds. HS...
Hidradenitis suppurativa (HS) is a common inflammatory disorder characterized by recurrent, painful, and malodorous abscesses and nodules predominantly in skin folds. HS is associated with substantial morbidity and poor quality of life. There are no curative therapies, and the only approved biologic drug has variable efficacy and requires high doses, making adjunct treatments crucial. An important risk factor for disease severity is obesity. Our primary objective was to conduct a systematic review examining weight loss and dietary interventions, in HS. Our secondary objective was to examine nutritional supplements in HS.A systematic literature search was conducted using Medline, EMBASE, and the Cochrane Database. We included all study types in adults (>18 years), with a minimum sample size of 5, examining the effects of any dietary or weight loss intervention on HS severity. Two authors screened = 1279 articles of which 9 met inclusion criteria. All included studies were observational and all interventions were associated with various measures of decreased HS severity. Patient-controlled weight loss and bariatric surgery were associated with HS regression, though a subset of patients with significant increase in panniculi experienced exacerbations and required excision of excess skin. Diets demonstrating benefit eliminated dairy and brewer's yeast. Nutritional supplements including zinc gluconate, vitamin D, and riboflavin had a suppressive, rather than curative, effect on HS lesions in single studies. Overall, the reviewed interventions show promise as potential adjunct treatments in a HS management plan. Prospective randomized controlled trials should validate these findings.
Topics: Dietary Supplements; Hidradenitis Suppurativa; Humans; Life Style; Quality of Life; Weight Loss
PubMed: 31502868
DOI: 10.1177/1203475419874412 -
The Ocular Surface Oct 2019To examine the efficacy of adjuvant photoactivated chromophore for infectious keratitis-corneal cross-linking (PACK-CXL) for the treatment of infectious keratitis (IK). (Meta-Analysis)
Meta-Analysis
PURPOSE
To examine the efficacy of adjuvant photoactivated chromophore for infectious keratitis-corneal cross-linking (PACK-CXL) for the treatment of infectious keratitis (IK).
METHODS
Electronic databases, including MEDLINE, EMBASE and Cochrane Central, were searched for articles related to PACK-CXL. All clinical studies, including randomized controlled trials (RCTs), non-randomized controlled studies, case series and case reports, were included. A meta-analysis was further performed when there were sufficient similarities in the included RCTs. Primary outcome measure was time to complete corneal healing and secondary outcome measures included size of epithelial defect and infiltrate, corrected-distance-visual-acuity (CDVA), and adverse events.
RESULTS
Forty-six eligible studies (including four RCTs) with 435 patients were included. When compared to standard antimicrobial treatment (SAT) alone, adjuvant PACK-CXL resulted in shorter mean time to complete corneal healing (-7.44 days; 95% CI, -10.71 to -4.16) and quicker resolution of the infiltrate at 7 days (-5.49 mm; 95% CI, -7.44 to -3.54) and at 14-30 days (-5.27 mm; 95% CI, -9.12 to -1.41). There was no significant difference in the size of epithelial defect, CDVA and risk of adverse events. Evidence on the use of PACK-CXL in acanthamoeba and mixed IK was insufficient.
CONCLUSIONS
Our study demonstrates that adjuvant PACK-CXL expedites the healing of IK when compared to SAT alone (low-quality evidence). Further adequately powered, high-quality RCTs are required to fully ascertain the therapeutic effect of PACK-CXL.
Topics: Chromophore-Assisted Light Inactivation; Collagen; Cross-Linking Reagents; Eye Infections, Bacterial; Humans; Keratitis; Photochemotherapy; Photosensitizing Agents; Riboflavin; Visual Acuity
PubMed: 31401338
DOI: 10.1016/j.jtos.2019.08.006 -
International Ophthalmology Nov 2019To compare the one-year efficacy of accelerated and standard 5.4 J/cm protocols of cross-linking (CXL) in the treatment of progressive keratoconus.
PURPOSE
To compare the one-year efficacy of accelerated and standard 5.4 J/cm protocols of cross-linking (CXL) in the treatment of progressive keratoconus.
METHODS
In this systematic review, two members of the research team searched Scopus, Pubmed, ISI, Ovid, Science Direct, and Cochrane databases independently for publications between January 2010 and December 2016. The majority of retrieved studies were not randomized clinical trials (RCT), or the second arm of the RCT was either untreated or customized CXL. The outcomes of interest were uncorrected distance visual acuity, corrected visual acuity, manifest refraction spherical equivalent, maximum keratometry in the central 3 mm, minimum keratometry in the central 3 mm, and corneal thickness in the apex or thinnest point at baseline and 1 year after CXL.
RESULTS
Of the 453 papers found in the preliminary search, 23 papers were included in the final analysis. Analysis of variance of one-year changes showed that longer irradiation times were associated with a greater corneal flattening effect, although there was no difference in terms of improvement in vision or refraction.
CONCLUSIONS
In other words, efficacy is comparable among different CXL protocols, so it is recommended to use the standard method in cases where maximum flattening is expected, such as young people and severe cases.
Topics: Collagen; Cornea; Corneal Topography; Cross-Linking Reagents; Humans; Keratoconus; Photochemotherapy; Photosensitizing Agents; Riboflavin; Visual Acuity
PubMed: 31222533
DOI: 10.1007/s10792-019-01091-y -
Journal of Refractive Surgery... Oct 2018To evaluate the outcomes of simultaneous and sequential corneal crosslinking (CXL) and excimer laser surface ablation protocols in keratoconus. (Comparative Study)
Comparative Study
PURPOSE
To evaluate the outcomes of simultaneous and sequential corneal crosslinking (CXL) and excimer laser surface ablation protocols in keratoconus.
METHODS
A literature review was conducted using MEDLINE. The studies were divided into three groups: the sequential group included studies with CXL followed by excimer laser surface ablation later, the simultaneous group included simultaneous excimer laser surface ablation and CXL, and the no CXL group included excimer laser surface ablation only with no CXL. The data on change in logMAR uncorrected distance visual acuity (UDVA), spectacle corrected distance visual acuity (CDVA), change in spherical equivalent (SE) and refractive astigmatism, change in maximum keratometry (Kmax), complications, and safety and efficacy indices were presented for the latest follow-up visits in all groups.
RESULTS
Twenty-one studies (3 = sequential; 11 = simultaneous, 7 = no CXL) were included. UDVA improved in all groups. CDVA improved more in the sequential group. SE change was greatest in the no CXL group and the refractive astigmatism reduced comparably in the sequential and no CXL groups but less in the simultaneous group. Kmax reduced in all groups. Only the sequential group showed no progression. Corneal haze was reported in 100%, 54.5%, and 57.1% studies, respectively. Safety and efficacy indices were 1.96 and 1.58, 1.41 ± 0.32 and 0.91 ± 0.41, and 1 and 0.82, respectively.
CONCLUSIONS
The sequential group showed greater improvement in CDVA, SE, and refractive astigmatism. Corneal haze was frequently reported in all protocols. Safety and efficacy indices were highest when CXL was performed before excimer laser and least when excimer laser was performed alone without CXL. [J Refract Surg. 2018;34(10):690-696.].
Topics: Collagen; Corneal Pachymetry; Corneal Stroma; Cross-Linking Reagents; Humans; Keratoconus; Lasers, Excimer; Photochemotherapy; Photorefractive Keratectomy; Photosensitizing Agents; Refraction, Ocular; Riboflavin; Ultraviolet Rays; Visual Acuity
PubMed: 30296330
DOI: 10.3928/1081597X-20180824-01 -
Cornea Aug 2018To systematically compare standard epithelium-off corneal collagen cross-linking (SCXL) and transepithelial corneal collagen cross-linking (TECXL) for treating... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To systematically compare standard epithelium-off corneal collagen cross-linking (SCXL) and transepithelial corneal collagen cross-linking (TECXL) for treating keratoconus.
METHODS
PubMed, EMBASE, the Cochrane Library, the US trial registry (ClinicalTrials.gov), VIP Database, Wanfang Databse, and China National Knowledge Infrastructure searches up to February 2017 were conducted. Primary outcomes were changes at 1 year in uncorrected distance visual acuity, maximum keratometry (Kmax), and mean keratometry (mean K). Secondary outcomes were changes at 1 year in corrected distance visual acuity, mean refractive spherical equivalent, central corneal thickness, endothelial cell density, and the occurrence of adverse events.
RESULTS
Eight studies with a total of 455 eyes were included. For primary outcomes, SCXL showed a greater reduction in mean K [standardized mean difference (SMD) 0.28; 95% confidence interval (CI), 0.03-0.53; P = 0.03] compared with TECXL. Subgroup analysis indicated that SCXL had a comparable effect on reducing mean K with TECXL protocols using chemical enhancers (SMD 0.05; 95% CI, -0.36 to 0.45; P = 0.82) but a greater reduction in mean K compared with TECXL with current iontophoretic protocols (SMD 0.43; 95% CI, 0.10-0.75; P = 0.01). For the other outcomes, there were no statistically significant differences.
CONCLUSIONS
With the exception of less reduction in mean K with current iontophoretic protocols, analysis of the limited number of comparative studies available seems to demonstrate that SCXL and TECXL have a comparable effect on visual, refractive, pachymetric, and endothelial parameters at 1 year after surgery. Further follow-up is required to determine whether these techniques are comparable in the long-term.
Topics: Collagen; Cornea; Corneal Pachymetry; Corneal Topography; Cross-Linking Reagents; Drug Administration Routes; Epithelium, Corneal; Humans; Keratoconus; Photochemotherapy; Photosensitizing Agents; Riboflavin; Ultraviolet Rays
PubMed: 29847492
DOI: 10.1097/ICO.0000000000001632 -
European Journal of Nutrition Jun 2019Several epidemiological studies have assessed the ability of vitamin B to prevent colorectal cancer (CRC), but the results are controversial results. We conducted a... (Meta-Analysis)
Meta-Analysis
PURPOSE
Several epidemiological studies have assessed the ability of vitamin B to prevent colorectal cancer (CRC), but the results are controversial results. We conducted a dose-response meta-analysis to investigate the association between vitamin B and CRC risk.
METHODS
We searched the PubMed and EMBASE database until January 3, 2018 to identify relevant studies. The pooled relative risks (RRs) with the corresponding 95% confidence intervals (CIs) were calculated using a random-effects model or fixed-effects model. The dose-response relationship was assessed by restricted cubic splines.
RESULTS
A total of 14 studies reporting vitamin B intake and two studies reporting blood vitamin B concentration, comprising 14,934 cases and 1593 cases, respectively, were included in the meta-analysis. Vitamin B intake was inversely associated with CRC risk (RR = 0.87; 95% CI 0.81-0.93). Similar results were found for total vitamin B intake from diet and supplements (RR = 0.86; 95% CI 0.78-0.94) and dietary vitamin B intake (RR = 0.89, 95% CI 0.82-0.98) in subgroup analyses. The dose-response model indicated a non-linear trend, and CRC risk was reduced by 10% when vitamin B intake increased to 5 mg/day. In addition, high blood concentrations of vitamin B could also reduce the CRC risk (RR = 0.74; 95% CI 0.59-0.92).
CONCLUSIONS
This dose-response analysis indicates that vitamin B intake is inversely associated with CRC risk. The inverse association may also exist between blood vitamin B concentration and CRC risk. These results suggest the importance of vitamin B intake in the prevention of CRC.
Topics: Colorectal Neoplasms; Dietary Supplements; Dose-Response Relationship, Drug; Humans; Riboflavin; Risk; Vitamin B Complex
PubMed: 29744609
DOI: 10.1007/s00394-018-1702-5