scholarly journals Vitamin C and Neutrophil Function: Findings from Randomized Controlled Trials

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2102 ◽  
Author(s):  
Mikee Liugan ◽  
Anitra C. Carr
Keyword(s):  
Enzyme Activity ◽  
Vitamin C ◽  
Oxidative Burst ◽  
Neutrophil Function ◽  
Antioxidant Enzyme Activity ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Ovid Medline ◽  
Oxidative Burst Activity ◽  
Intravenous Vitamin

Vitamin C is known to support immune function and is accumulated by neutrophils to millimolar intracellular concentrations suggesting an important role for the vitamin in these cells. In this review, the effects of vitamin C, as a mono- or multi-supplement therapy, on neutrophil function were assessed by conducting a systematic review of randomized controlled trials (RCTs). Specifically, trials which assessed neutrophil migration (chemotaxis), phagocytosis, oxidative burst, enzyme activity, or cell death (apoptosis) as primary or secondary outcomes were assessed. A systematic literature search was conducted using the Cochrane Central Register of Controlled Trials, EMBASE, Embase Classic, Joanna Briggs Institute EBP, Ovid MEDLINE®, Ovid MEDLINE® In-Process & Other Non-Indexed Citations, Ovid Nursing Database, CINAHL and PubMed database, which identified 16 eligible RCTs. Quality appraisal of the included studies was carried out using the Cochrane Risk of Bias tool. Three of the studies assessed neutrophil chemotaxis in hospitalised patients or outpatients, two of which showed improved neutrophil function following intravenous vitamin C administration. Ten RCTs assessed neutrophil phagocytosis and/or oxidative burst activity; five were exercise studies, one in smokers, one in myocardial infarction patients and three in healthy volunteers. Two of the multi-supplement studies showed a difference between the intervention and control groups: increased oxidative burst activity in athletes post-exercise and decreased oxidant generation in myocardial infarction patients. Two studies assessed neutrophil enzyme activity; one showed deceased antioxidant enzyme activity in divers and the other showed increased antioxidant enzyme activity in athletes. One final study showed decreased neutrophil apoptosis in septic surgical patients following intravenous vitamin C administration. Overall, 44% of the RCTs assessed in this review showed effects of vitamin C supplementation on neutrophil functions. However, the studies were very heterogeneous, comprising different participant cohorts and different dosing regimens. There were also a number of limitations inherent in the design of many of these RCTs. Future RCTs should incorporate prescreening of potential participants for low vitamin C status or utilize cohorts known to have low vitamin status, such as hospitalized patients, and should also comprise appropriate vitamin C dosing for the cohort under investigation.

scholarly journals Application of Intravenous Vitamin C in Adult Patients with Sepsis: A Meta-Analysis of Randomized Controlled Trials

2021 ◽  
Author(s):  
Han-Bing Chen ◽  
Peng Chen ◽  
Kang Li ◽  
Jun Shao
Keyword(s):  
Vitamin C ◽  
Randomized Controlled Trials ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Adult Patients ◽  
Cochrane Library ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Intravenous Vitamin ◽  
Quality Evidence

Abstract Background: The efficacy of intravenous vitamin C among sepsis patients is uncertain according to recent randomized controlled trials (RCTs). We conducted a meta-analysis to evaluate the efficacy of vitamin C application in adults with sepsis.Methods: We performed a systematic literature search in PubMed, Web of Science, Embase and the Cochrane Library. Eligible studies were RCTs that investigated the application of intravenous vitamin C in adult patients with sepsis. We assessed the risk of bias of the included studies using the Cochrane risk of bias tool and the certainty of evidence according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, for each outcome.Results: Fourteen trials involving a total of 1823 patients were included. We found that there was no significant effect of vitamin C on 28-day mortality [risk ratio (RR) 0.87, 95% confidence interval (CI) 0.73 to 1.04, p = 0.12, TSA-adjusted CI 0.70 to 1.08, low quality evidence], but among patients who were treated with vitamin C monotherapy instead of combination therapy, the mortality was reduced (RR 0.66, 95% CI 0.49 to 0.88, p = 0.004). Vitamin C was associated with a significant improvement of 72-h ΔSOFA score (SMD = 0.20, 95% CI 0.07 to 0.32, p = 0.002, I2=11%, moderate quality evidence).Conclusions: In this meta-analysis of patients with sepsis, the use of vitamin C was not associated with reduction in 28-day mortality, but vitamin C may have a positive effect in improving organ function. As the certainty of evidence was low, Larger RCTs were needed.

Vitamin C, Thiamine, and Hydrocortisone in the Treatment of Sepsis: A Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

2021 ◽  
pp. 088506662098780
Author(s):  
Yazan Zayed ◽  
Bashar N. Alzghoul ◽  
Momen Banifadel ◽  
Hima Venigandla ◽  
Ryan Hyde ◽  
...  
Keyword(s):  
Septic Shock ◽  
Length Of Stay ◽  
Vitamin C ◽  
Sofa Score ◽  
Sequential Analysis ◽  
Trial Sequential Analysis ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Icu Length Of Stay ◽  
Significant Difference

Background: There is a conflicting body of evidence regarding the benefit of vitamin C, thiamine, and hydrocortisone in combination as an adjunctive therapy for sepsis with or without septic shock. We aimed to assess the efficacy of this treatment among predefined populations. Methods: A literature review of major electronic databases was performed to include randomized controlled trials (RCTs) evaluating vitamin C, thiamine, and hydrocortisone in the treatment of patients with sepsis with or without septic shock in comparison to the control group. Results: Seven studies met our inclusion criteria, and 6 studies were included in the final analysis totaling 839 patients (mean age 64.2 ± 18; SOFA score 8.7 ± 3.3; 46.6% female). There was no significant difference between both groups in long term mortality (Risk Ratio (RR) 1.05; 95% CI 0.85-1.30; P = 0.64), ICU mortality (RR 1.03; 95% CI 0.73-1.44; P = 0.87), or incidence of acute kidney injury (RR 1.05; 95% CI 0.80-1.37; P = 0.75). Furthermore, there was no significant difference in hospital length of stay, ICU length of stay, and ICU free days on day 28 between the intervention and control groups. There was, however, a significant difference in the reduction of SOFA score on day 3 from baseline (MD −0.92; 95% CI −1.43 to −.41; P < 0.05). In a trial sequential analysis for mortality outcomes, our results are inconclusive for excluding lack of benefit of this therapy. Conclusion: Among patients with sepsis with or without septic shock, treatment with vitamin C, thiamine, and hydrocortisone was not associated with a significant reduction in mortality, incidence of AKI, hospital and ICU length of stay, or ICU free days on day 28. There was a significant reduction of SOFA score on day 3 post-randomization. Further studies with a larger number of patients are needed to provide further evidence on the efficacy or lack of efficacy of this treatment.

scholarly journals PubMed is Slightly More Sensitive but More Time Intensive to Search than Ovid MEDLINE

2011 ◽  
Vol 6 (2) ◽  
pp. 51
Author(s):  
Cari Merkley
Keyword(s):  
Rheumatoid Arthritis ◽  
Systematic Review ◽  
Randomized Controlled Trials ◽  
Controlled Trials ◽  
Medline Search ◽  
Search Results ◽  
Randomized Controlled ◽  
Ovid Medline ◽  
Mesh Terms ◽  
The University

Objective — To compare the results of searching the MEDLINE database through Ovid and the free online version of PubMed administered by the National Library of Medicine for randomized controlled trials on the subject of the drug methotrexate (MTX) for patients suffering from rheumatoid arthritis. Design — Comparative analysis of search results. Setting — Searches conducted by researchers affiliated with Mahidol University in Bangkok, Thailand, and the University of Toronto and the University Health Network in Toronto, Ontario. Subjects — A total of 3966 search results obtained from Ovid MEDLINE and PubMed. Methods — This study employs an Ovid MEDLINE search strategy originally created for a published systematic review that identified randomized controlled trials on MTX and rheumatoid arthritis (Katchamart, Trudeau, Phumethum, & Bombardier, 2009). Two of the authors of the original systematic review (Katchamart and Bombardier) are among the authors of this current study. Appropriate medical subject heading (MeSH) terms and their synonyms were identified for the three main concepts (rheumatoid arthritis, MTX, and randomized controlled trials). The search was performed in Ovid MEDLINE, seeking articles in any language that met the search criteria, from the earliest date covered by MEDLINE to January 2009. Each MeSH or keyword term within a concept was searched separately, and then combined with other like terms using the Boolean operator OR. The searches for the three concepts were finally combined using AND. The Ovid MEDLINE search was then translated for use in PubMed by an information professional. The formatting and terminology used in some of the original Ovid MEDLINE search statements had to be changed so they would work in the new database environment, but the researchers tried to ensure that the two searches were as similar as possible. The translated search was then executed in PubMed. The final results, as well as the number of articles retrieved for each key search concept (rheumatoid arthritis, MTX, and randomized controlled trials), were then compared. The final results were further analyzed for measures of sensitivity, precision, and number needed to read. Sensitivity is calculated by the number of eligible studies found in a database divided by the “total number of eligible studies in the review” multiplied by 100 (Katchamart, Faulkner, Feldman, Tomlinson, & Bombardier, p. 806). Eligible studies were identified using the inclusion/exclusion criteria developed by Katchamart et al. The figure for “total number of eligible studies in the review” is taken from that same study, which forms the “gold standard” for this analysis (Katchamart et al., p. 806). Precision is calculated by dividing the total number of eligible citations from a database by the total number of citations returned by the database for the search multiplied by 100 (Katchamart et al., p. 806). The number needed to read (NNR) formula used by the authors is 1/precision, taken from a study by Bachman, Coray, Estermann, and Ter Riet (2002). Main Results — The PubMed search found more results than Ovid MEDLINE for each of the three key concepts – rheumatoid arthritis, MTX and randomized controlled trials. Once the three concepts were combined, PubMed found 106 more articles than Ovid MEDLINE (2036 vs. 1930). Once the review eligibility criteria were applied to the search results from PubMed, 18 eligible articles were identified, one more article than in Ovid MEDLINE. The authors indicated that the additional article located in PubMed was from a journal that was not yet indexed by MEDLINE at the time the relevant article was published. To determine database sensitivity, these numbers were then divided by 20, the total number of eligible studies located in the Katachamart et al. 2009 review, which employed tools like EMBASE and strategies like hand searching in addition to MEDLINE in order to identify relevant studies. Because of the additional study it located, the sensitivity of PubMed was determined to be slightly higher than Ovid MEDLINE (90% vs. 85%). There was little difference between the two databases in terms of precision and NNR. Precision for Ovid MEDLINE was calculated at 0.881% and at 0.884% for PubMed. The NNR was 114 for Ovid MEDLINE and 113 for PubMed. Conclusion — The authors state that while PubMed had a higher calculated sensitivity than Ovid MEDLINE in the context of this particular search because it contained content not indexed by Ovid MEDLINE that proved to be relevant for this topic, its precision and NNR were almost equal to MEDLINE’s. Some technical limitations of the PubMed interface were experienced by researchers during the study, such as periodic instability and the inability to save and modify searches and their results line by line. These same issues did not arise while using Ovid MEDLINE. The need for a skilled translation of Ovid MEDLINE searches for use in the PubMed interface was also emphasized by the authors, as differences in syntax and formatting that are not properly addressed could impact PubMed’s sensitivity and precision.

scholarly journals Effects of Acute Heat and Cold Exposures at Rest or during Exercise on Subsequent Energy Intake: A Systematic Review and Meta-Analysis

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3424
Author(s):  
Juliette Millet ◽  
Julien Siracusa ◽  
Pierre-Emmanuel Tardo-Dino ◽  
David Thivel ◽  
Nathalie Koulmann ◽  
...  
Keyword(s):  
Energy Intake ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Small Decrease ◽  
Eligibility Criteria ◽  
Randomized Controlled ◽  
Ovid Medline ◽  
Study Selection ◽  
Ad Libitum ◽  
Rest And Exercise

The objective of this meta-analysis was to assess the effect of acute heat/cold exposure on subsequent energy intake (EI) in adults. We searched the following sources for publications on this topic: PubMed, Ovid Medline, Science Direct and SPORTDiscus. The eligibility criteria for study selection were: randomized controlled trials performed in adults (169 men and 30 women; 20–52 years old) comparing EI at one or more meals taken ad libitum, during and/or after exposure to heat/cold and thermoneutral conditions. One of several exercise sessions could be realized before or during thermal exposures. Two of the thirteen studies included examined the effect of heat (one during exercise and one during exercise and at rest), eight investigated the effect of cold (six during exercise and two at rest), and three the effect of both heat and cold (two during exercise and one at rest). The meta-analysis revealed a small increase in EI in cold conditions (g = 0.44; p = 0.019) and a small decrease in hot conditions (g = −0.39, p = 0.022) for exposure during both rest and exercise. Exposures to heat and cold altered EI in opposite ways, with heat decreasing EI and cold increasing it. The effect of exercise remains unclear.

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