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Advances in Nutrition (Bethesda, Md.) May 2024A systematic review and meta-analysis was conducted to assess the relationship between the common dietary antioxidants vitamin C, vitamin E, and β-carotene and type 2... (Meta-Analysis)
Meta-Analysis Review
A systematic review and meta-analysis was conducted to assess the relationship between the common dietary antioxidants vitamin C, vitamin E, and β-carotene and type 2 diabetes (T2D) and related traits. MEDLINE, Embase, and the Cochrane Library were searched for relevant publications up until May 2023. Studies were eligible if they had a cohort, case-control, or randomized controlled trial (RCT) design and examined dietary intake, supplementation, or circulating levels of these antioxidants as exposure, and insulin resistance, β-cell function, or T2D incidence as outcomes. Summary relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI) were estimated using random-effects models. The certainty of the evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluations framework. Among 6190 screened records, 25 prospective observational studies and 15 RCTs were eligible. Inverse associations were found between dietary and circulating antioxidants and T2D (observational studies). The lowest risk was seen at intakes of 70 mg/d of vitamin C (RR: 0.76; CI: 0.61, 0.95), 12 mg/d of vitamin E (RR: 0.72; CI: 0.61, 0.86), and 4 mg/d of β-carotene (RR: 0.78; CI: 0.65, 0.94). Supplementation with vitamin E (RR: 1.01; CI: 0.93, 1.10) or β-carotene (RR: 0.98; CI: 0.90, 1.07) did not have a protective effect on T2D (RCTs), and data on vitamin C supplementation was limited. Regarding insulin resistance, higher dietary vitamin C (RR: 0.85; CI: 0.74, 0.98) and vitamin E supplementation (MD: -0.35; CI: -0.65, -0.06) were associated with a reduced risk. The certainty of evidence was high for the associations between T2D and dietary vitamin E and β-carotene, and low to moderate for other associations. In conclusion, moderate intakes of vitamins C, E, and β-carotene may lower risk of T2D by reducing insulin resistance. Lack of protection with supplementation in RCTs suggests that adequate rather than high intakes may play a role in T2D prevention. This systematic review and meta-analysis was registered in PROSPERO with registration number CRD42022343482.
Topics: Diabetes Mellitus, Type 2; Humans; beta Carotene; Ascorbic Acid; Vitamin E; Antioxidants; Dietary Supplements; Insulin Resistance; Diet; Risk Factors; Male; Female; Middle Aged; Adult; Aged
PubMed: 38493875
DOI: 10.1016/j.advnut.2024.100211 -
BMC Ophthalmology Mar 2024Polyethylene covers have been proven to be effective in protecting the eyes in patients with decreased or disappeared blink reflexes, but their advantages compared to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Polyethylene covers have been proven to be effective in protecting the eyes in patients with decreased or disappeared blink reflexes, but their advantages compared to other conventional methods are still unclear. This systematic review and meta-analysis study aimed to elucidate the impact of polyethylene covers in the prevention of ocular surface disease (OSD) in patients admitted to the intensive care unit (ICU).
METHODS
We searched the Scopus, PubMed, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases to identify randomized controlled trial studies. This study followed the PRISMA guidelines and used the Cochrane Collaboration tool to assess the risk of bias.
RESULTS
The findings were expressed as risk ratio (RR) with 95% confidence intervals. The incidence of OSD in the polyethylene cover group was lower than that in the eye drops group (RR = 0.27; 95% CI (0.07, 1.09), P = 0.07) and adhesive tape group (RR = 0.11, 95%CI (0.04, 0.31), P < 0:0001) but the polyethylene cover group showed no significant difference compared to the eye gel group (RR = 0.79, 95%CI (0.18, 3.51), P = 0.76) and the eye ointment group (RR = 0.85; 95% CI (0.36, 1.99), P = 0.71).
CONCLUSION
This study showed that polyethylene covers, eye gels, and eye ointments had an equal effect on preventing OSD in ICU patients, and eye drops and adhesive tapes were relatively less effective. However, other intervention methods had not been compared due to the small number of articles. Hence, further studies should assess the available methods to choose the best practical method.
Topics: Humans; Polyethylene; Eye Diseases; Eye; Intensive Care Units; Ophthalmic Solutions
PubMed: 38448859
DOI: 10.1186/s12886-024-03360-6 -
Advances in Nutrition (Bethesda, Md.) Jan 2024Carotenoids appear to have anticancer effects. Prospective evidence for the relation between serum carotenoids and breast cancer is controversial. The present systematic... (Meta-Analysis)
Meta-Analysis Review
Carotenoids appear to have anticancer effects. Prospective evidence for the relation between serum carotenoids and breast cancer is controversial. The present systematic review and meta-analysis aimed to investigate the link between circulating carotenoids and the risk of breast cancer. We performed a systematic search of PubMed, Scopus, and Web of Science up to 30 November, 2022. Prospective studies on adults aged ≥18 y that have reported risk estimates for the association between circulating carotenoids and breast cancer risk were considered. Study quality was assessed using the Newcastle-Ottawa Scale. A random-effects model was used for combining studies' risk estimates. Dose-response relations were explored through a 1-stage random-effects model. Fifteen publications (17 nested case-control studies and 1 cohort study) with 20,188 participants and 7608 cases were included. We observed an inverse association between the highest level of circulating total carotenoids (relative risk [RR]: 0.76; 95% confidence interval [CI]: 0.62, 0.93; n = 8), α-carotene (RR: 0.77; 95% CI: 0.68, 0.87; n = 13), β-carotene (RR: 0.80; 95% CI: 0.65, 0.98; n = 15), β-cryptoxanthin (RR: 0.85; 95% CI: 0.74, 0.96; n = 11), lycopene (RR: 0.86; 95% CI: 0.76, 0.98; n = 13), and lutein (RR: 0.70; 95% CI: 0.52, 0.93; n = 6) and the risk of breast cancer compared with the lowest level. Additionally, each 10 μg/dL of total carotenoids, α-carotene, β-carotene, and β-cryptoxanthin was associated with 2%, 22%, 4%, and 10% lower risk of breast cancer, respectively. This relationship was stronger at lower levels of total carotenoids and β-cryptoxanthin. The certainty of evidence was rated from very low to low. Most studies were performed among Western nations, which should be acknowledged for extrapolation of findings. Total circulating carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein seem to be related to a decreased risk of breast cancer. Our findings could have practical importance for public health. This study was registered at PROSPERO as CRD42023434983.
Topics: Adult; Female; Humans; beta Carotene; Beta-Cryptoxanthin; Breast Neoplasms; Carotenoids; Lutein; Lycopene
PubMed: 38436219
DOI: 10.1016/j.advnut.2023.10.007 -
BMJ Open Jan 2024The objective of the current study is to compare the treatment effects of different vitamins on essential hypertension to provide an initial basis for developing... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
The objective of the current study is to compare the treatment effects of different vitamins on essential hypertension to provide an initial basis for developing evidence-based practices.
DESIGN
Systematic review and network meta-analysis.
DATA SOURCES
Five electronic databases (PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched from their inception to 25 September 2023.
OUTCOMES
The primary outcomes were the difference between the intervention group and the control group in changes in office systolic blood pressure (SBP) and office diastolic blood pressure (DBP) from baseline. The secondary outcomes were the difference between the intervention group and the control group in changes in 24-hour mean ambulatory systolic blood pressure (24 hours SBP), 24-hour mean ambulatory diastolic blood pressure (24 hours DBP) and heart rate (HR) from baseline.
RESULTS
A total of 23 studies comparing five vitamins (vitamin B, vitamin C, vitamin D, vitamin E, folic acid) and involving 2218 participants were included. The included trials were all vitamin versus placebo, so the network was star-shaped. Among the five vitamins, only vitamin E was significantly more effective at reducing SBP (mean difference: -14.14 mm Hg, 95% credible intervals: -27.62 to -0.88) than placebo. In addition, no evidence was found that any of the five vitamins influenced DBP, 24 hours SBP, 24 hours DBP, or HR. The dose of vitamins, geographical region and percentage of males (only SBP) might be sources of heterogeneity. Sensitivity and subgroup analysis revealed that the effect of vitamin intervention on blood pressure varies according to different doses of vitamins.
CONCLUSIONS
According to the results, vitamin E might be an effective measure to reduce SBP, but more research is needed to validate this finding.
PROSPERO REGISTRATION NUMBER
CRD42022352332.
Topics: Adult; Male; Humans; Vitamin D; Ascorbic Acid; Hypertension; Folic Acid; Riboflavin; Vitamin E; Network Meta-Analysis; Vitamins; Essential Hypertension; Blood Pressure; Vitamin A; Vitamin K
PubMed: 38296289
DOI: 10.1136/bmjopen-2023-074511 -
BMC Gastroenterology Jan 2024Gastric cancer is characterized by high invasiveness, heterogeneity, and late diagnosis, leading to high incidence and mortality rates. It is a significant public health... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Gastric cancer is characterized by high invasiveness, heterogeneity, and late diagnosis, leading to high incidence and mortality rates. It is a significant public health concern globally. Early prevention is crucial in reducing the occurrence of gastric cancer, and dietary prevention, particularly focusing on carotenoids, has been considered a convenient and effective approach. However, the association between carotenoid intake and gastric cancer incidence remains controversial.
METHODS
A systematic search was conducted in PubMed, Ovid Embase, Web of Science, and Cochrane databases from inception to January 5, 2023. Two reviewers independently screened search results, extracted relevant data, and evaluated study quality. Statistical analysis was performed using the "metan" command in STATA 16 software. Random-effects or fixed-effects models were chosen based on the magnitude of heterogeneity among studies.
RESULTS
This study included a total of 35 publications, consisting of 23 case-control studies and 12 cohort studies. Meta-analysis of case-control studies showed that alpha-carotene (OR = 0.71, 95% CI: 0.55-0.92), beta-carotene (OR = 0.62, 95% CI: 0.53-0.72), and lutein (OR = 0.82, 95% CI: 0.69-0.97) significantly reduced the risk of gastric cancer, while beta-cryptoxanthin (OR = 0.88, 95% CI: 0.75-1.04) and lycopene (OR = 0.86, 95% CI: 0.73-1.00) showed no significant correlation. Meta-analysis of cohort studies indicated no significant associations between any of the five carotenoids and gastric cancer incidence (alpha-carotene: RR = 0.81, 95% CI: 0.54-1.23; beta-carotene: RR = 0.86, 95% CI: 0.64-1.16; beta-cryptoxanthin: RR = 0.86, 95% CI: 0.64-1.16; lutein: RR = 0.94, 95% CI: 0.69-1.29; lycopene: RR = 0.89, 95% CI: 0.69-1.14).
CONCLUSIONS
The relationship between carotenoids and gastric cancer incidence may vary depending on the type of study conducted. Considering that evidence from cohort studies is generally considered stronger than evidence from case-control studies, and high-quality randomized controlled trials show no significant association between carotenoids and gastric cancer incidence, current evidence does not support the supplementation of carotenoids for gastric cancer prevention. Further targeted research is needed to explore the association between the two.
Topics: Humans; beta Carotene; Lycopene; Lutein; Stomach Neoplasms; Beta-Cryptoxanthin; Risk Factors; Carotenoids
PubMed: 38287248
DOI: 10.1186/s12876-024-03139-5 -
BMC Oral Health Jan 2024The effectiveness of newly developed elastomeric polymer hybrid siloxane (PVES), which combines the properties of polyethylene (PE) and polyvinyl siloxane (PVS)... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The effectiveness of newly developed elastomeric polymer hybrid siloxane (PVES), which combines the properties of polyethylene (PE) and polyvinyl siloxane (PVS) elastomers, has been a subject of interest in recent studies. This study aimed to assess the physical properties of hybrid PVES materials by analyzing existing data from recent studies on this topic.
METHODS
A systematic literature search was conducted to retrieve peer-reviewed articles published up to February 5, 2023. The population, intervention, comparison, and pertinent outcomes were specified under the PICO framework. The primary data analysis was performed in Microsoft Excel, while statistical analysis used Meta-Essentials.
RESULTS
Of the 1152 articles assessed, 14 met the inclusion criteria. The meta-analysis of the selected studies indicated that polyether (PE) and polyvinyl siloxane (PVS) were highly correlated (two-tailed p-values of 0.000 and 0.001, respectively) with the improved tensile strength of vinyl polyether siloxane (PVES) with a significantly positive effect size. Similarly, the hydrophilic characteristics of PVES were significantly improved compared to those of PE and PVS. PE was a significant contributor to the hydrophilic characteristics of PVES, with a two-tailed p-value of 0.000. The effect size was highly positive for hydrophilicity but showed high heterogeneity. It was also observed that the dimensional accuracy of PVES was comparable to those of PE and PVS, with no statistically significant differences among the three materials.
CONCLUSIONS
PVES showed promising features, with improved tensile strength and hydrophilic characteristics compared to those of PE and PVS.
Topics: Humans; Siloxanes; Polyethylene; Elastomers; Parents
PubMed: 38195442
DOI: 10.1186/s12903-023-03830-1 -
Journal of Nutritional Science and... 2023The role of vitamin A in the pathophysiological context of coronavirus disease 2019 (COVID-19) represents a current challenge, given the major impact of COVID-19 on...
The role of vitamin A in the pathophysiological context of coronavirus disease 2019 (COVID-19) represents a current challenge, given the major impact of COVID-19 on morbidity and mortality and the importance of retinol in pulmonary and immunomodulatory functions. The aim of this review is to assess the relationship between vitamin A nutritional status and clinical outcomes in people with COVID-19. The PubMed, Web of Science, Scopus and ScienceDirect databases were used to search for observational studies that assessed retinol levels in hospitalized individuals with COVID-19, following the PRISMA recommendations. A total of 1,912 articles were identified and seven met the inclusion criteria. Four studies showed borderline or deficient retinol blood levels (retinol <0.20 mg/L or <0.70 mol/L) in people with COVID-19, associated with worsened clinical outcomes. In the other three studies lower mean values of this vitamin were identified in COVID-19 symptomatic groups compared to asymptomatic or convalescent groups that showed worse clinical outcomes. The results suggest a possible association between retinol and COVID-19 outcomes. However, there is a clear need to develop clinical trials to elucidate the role of vitamin A in the pathophysiological process of COVID-19.
Topics: Humans; COVID-19; Vitamin A; SARS-CoV-2; Nutritional Status; Vitamins
PubMed: 38171811
DOI: 10.3177/jnsv.69.395 -
Nutrients Dec 2023This systematic review aims to assess whether edible vegetable oils and fats fortified with vitamin A and/or D are effective and safe in improving vitamin intake and... (Meta-Analysis)
Meta-Analysis Review
Benefits and Harms of Edible Vegetable Oils and Fats Fortified with Vitamins A and D as a Public Health Intervention in the General Population: A Systematic Review of Interventions.
This systematic review aims to assess whether edible vegetable oils and fats fortified with vitamin A and/or D are effective and safe in improving vitamin intake and ameliorating deficiency states in the general population. In November 2022, we systematically searched MEDLINE, Cochrane CENTRAL, Scopus, Global Index Medicus, ClinicalTrials.gov, and WHO ICTRP (International Clinical Trials Registry Platform) for randomized controlled trials (RCT) and non-randomized studies of interventions (NRSI) investigating the fortification of edible vegetable oils and fats with either vitamin A or vitamin D or both as compared to the same vegetable oils and/or fats without vitamin A and D fortification or no interventions, in the general population, without age restriction. We assessed the methodological quality of included RCTs using Cochrane's risk of bias tool 2.0 and of NRSIs using ROBINS-I tool. We performed random-effects meta-analysis and assessed certainty of evidence using GRADE. We included eight studies. Available evidence showed no significant effect of fortification with vitamin A on serum retinol levels (RCTs: MD 0.35 µmol/L, 95% CI -0.43 to 1.12; two trials; 514 participants; low-certainty evidence; CCTs: MD 0.31 µmol/L, 95% CI -0.18 to 0.80; two trials; 205 participants; very low-certainty evidence) and on subclinical vitamin A deficiency. Low-certainty evidence showed no effect of vitamin D fortification on serum 25-hydroxy vitamin D concentration (MD 6.59 nmol/L, 95% CI -6.89 to 20.07; one trial; 62 participants). In conclusion, vitamin A-fortified vegetable oils and fats may result in little to no difference in serum retinol levels in general populations. The dose of vitamin A used in the trials may be safe but may not be sufficient to reduce subclinical vitamin A deficiency. Further, the evidence suggests that vitamin D fortification results in little to no difference in serum 25-hydroxy vitamin D concentration. Several aspects of providing fortified oils and fats to the general population as a public health intervention should be further investigated, including optimal fortification dose, effects on vitamin D deficiency and its clinical symptoms and potential adverse effects.
Topics: Humans; Vitamins; Vitamin A; Vitamin A Deficiency; Vegetables; Public Health; Plant Oils; Food, Fortified; Vitamin K; Vitamin D
PubMed: 38140394
DOI: 10.3390/nu15245135 -
Nutrients Nov 2023Adults with Crohn's disease (CD) may be at risk of micronutrient insufficiency in clinical remission through restrictive eating, malabsorption, abnormal losses or... (Review)
Review
Adults with Crohn's disease (CD) may be at risk of micronutrient insufficiency in clinical remission through restrictive eating, malabsorption, abnormal losses or inflammation. This systematic review synthesises the literature on micronutrient insufficiency in CD in clinical remission in terms of the prevalence of low circulating micronutrient concentrations and as a comparison against a healthy control (HC). Studies were included if the population was predominantly in remission. A total of 42 studies met the inclusion criteria; 12 were rated as low quality, leaving 30 studies covering 21 micronutrients of medium/high quality that were included in the synthesis. Vitamins D and B12 were the most frequently reported nutrients (8 and 11); there were few eligible studies for the remaining micronutrients. The prevalence studies were consistent in reporting individuals with low Vitamins A, B6, B12 and C, β-carotene, D, Magnesium, Selenium and Zinc. The comparator studies were inconsistent in finding differences with CD populations; Vitamin D, the most reported nutrient, was only lower than the HC in one-quarter of the studies. Adult CD populations are likely to contain individuals with low levels of one or more micronutrients, with the most substantial evidence for Vitamins D and B12. The studies on other micronutrients are of insufficient number, standardisation and quality to inform practice.
Topics: Adult; Humans; Micronutrients; Crohn Disease; Trace Elements; Vitamins; Vitamin A; Cholecalciferol
PubMed: 38004171
DOI: 10.3390/nu15224777 -
International Journal of Molecular... Nov 2023Diabetes is a serious chronic metabolic disease that causes complications over time, bringing serious public health challenges that affect different countries across the... (Review)
Review
Diabetes is a serious chronic metabolic disease that causes complications over time, bringing serious public health challenges that affect different countries across the world. The current clinical drugs for diabetes may lead to adverse effects such as hypoglycemia and liver and abdominal distension and pain, which prompt people to explore new treatments for diabetes without side effects. The research objective of this review article is to systematically review studies on vitamins and diabetes and to explain their possible mechanism of action, as well as to assess the role of vitamins as drugs for the prevention and treatment of diabetes. To achieve our objective, we searched scientific databases in PubMed Central, Medline databases and Web of Science for articles, using "vitamin" and "diabetes" as key words. The results of numerous scientific investigations revealed that vitamin levels were decreased in humans and animals with diabetes, and vitamins show promise for the prevention and/or control of diabetes through anti-inflammation, antioxidation and the regulation of lipid metabolism. However, a few studies showed that vitamins had no positive effect on the development of diabetes. Currently, studies on vitamins in the treatment of diabetes are still very limited, and there are no clinical data to clarify the dose-effect relationship between vitamins and diabetes; therefore, vitamins are not recommended as routine drugs for the treatment of diabetes. However, we still emphasize the great potential of vitamins in the prevention and treatment of diabetes, and higher quality studies are needed in the future to reveal the role of vitamins in the development of diabetes.
Topics: Humans; Vitamins; Dietary Supplements; Vitamin A; Vitamin K; Diabetes Mellitus
PubMed: 38003557
DOI: 10.3390/ijms242216371