The effect of niacin on inflammatory markers and adipokines: a systematic review and meta-analysis of interventional studies.

PURPOSE: Niacin (nicotinic acid), known for its lipid-modifying effects, has been explored for its potential anti-inflammatory properties and potential to affect adipokines secretion from adipose tissue. The aim of this systematic review and meta-analysis was to assess the effects of niacin on inflammatory markers and adipokines. METHODS: A comprehensive search was conducted across five databases: PubMed, Scopus, Cochrane Library, Embase, and ISI Web of Science. Randomized controlled trials exploring the effects of niacin on inflammatory markers (CRP, IL-6, TNF-α) and adipokines (Adiponectin, Leptin) were included. Pooled effect sizes were analysed using a random-effects model, and additional procedures including subgroup analyses, sensitivity analysis and dose-response analysis were also performed. RESULTS: From an initial 1279 articles, fifteen randomized controlled trials (RCTs) were included. Niacin administration demonstrated a notable reduction in CRP levels (SMD: -0.88, 95% CI: -1.46 to -0.30, p = 0.003). Subgroup analyses confirmed CRP reductions in trials with intervention durations ≤ 24 weeks, doses ≤ 1000 mg/day, and elevated baseline CRP levels (> 3 mg/l). The meta-analysis of IL-6 and TNF-α revealed significant TNF-α reductions, while IL-6 reduction did not reach statistical significance. Niacin administration also substantially elevated Adiponectin (SMD: 3.52, 95% CI: 0.95 to 6.1, p = 0.007) and Leptin (SMD: 1.90, 95% CI: 0.03 to 3.77, p = 0.04) levels. CONCLUSION: Niacin treatment is associated with significant reductions in CRP and TNF-α levels, suggesting potential anti-inflammatory effects. Additionally, niacin positively influences adipokines, increasing Adiponectin and Leptin levels. These findings provide insights for future research and clinical applications targeting inflammation and metabolic dysregulation.

Effect of Vitamin E Supplementation on Plasma and Urine Levels of Isoprostane F2α in Randomized Controlled Clinical Trials: A Systematic Review and Meta-Analysis.

Vitamin E can reduce the level of lipid peroxidation and the related markers such as urine and plasma levels of isoprostanes. However, effects of vitamin E supplementation on plasma and urine level of isoprostane F2α as markers of lipid peroxidation were conflicting in various clinical trials. The current meta-analysis was carried out to determine the effects of vitamin E supplementation on plasma and urine levels of isoprostanes F2α in randomized clinical trials. A systematic search of RCTs was carried out in PubMed, Scopus, Science Direct and Cochrane Library databases. OF 889 relevantly founded articles, only four articles with five arms met the criteria for meta-analysis of plasma level of isoprostanes F2α. For the urine level of isoprostane F2α, three studies with 14 arms were included in the meta-analysis. After pooled analyzing, a significant reduction of 6.98 ng / l was seen in plasma level of isoprostane F2α in vitamin E receiving group (95% CI = -11.2, -2.76; P < 0.001) while no significant heterogeneity was seen between the studies included in this meta-analysis (P = 0.81 and I2 = 0.0%). However, the pooled effect of vitamin E supplementation on urine level of isoprostane F2α was not statistically significant (-11.31 pg / mg creatinine (95% CI = -26.4, 3.78; P = 0.88). Results of this meta-analysis have shown that vitamin E supplementation can only reduce plasma level of isoprostane F2α and has no significant effect on reducing urine level of this biomarker.

Associations between diet and disease progression and symptomatology in multiple sclerosis: A systematic review of observational studies.

BACKGROUND: Although many people with MS (pwMS) modify their diet after diagnosis, there is still no consensus on dietary recommendations for pwMS. A number of observational studies have explored associations of diet and MS progression, but no studies have systematically reviewed the evidence. This systematic review aimed to provide an objective synthesis of the evidence for associations between diet and MS progression, including symptoms and clinical outcomes from observational studies. METHODS: We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic database searches were performed for studies completed up to 26 July 2023 using PubMed (Medline), Web of Science, CINAHL, Embase (Ovid), and Scopus, followed by citation and reference list checking. We included studies using diet quality scores or dietary indices. Studies assessing individual foods, nutrients, or dietary supplements were excluded. We used the Newcastle-Ottawa Scale to assess the risk of bias of included studies. RESULTS: Thirty-two studies met the inclusion criteria. Of these, 20 were cross-sectional and 12 prospective. The most frequent outcomes assessed were disability (n = 19), quality of life (n = 12), fatigue (n = 12), depression (n = 9), relapse (n = 8), anxiety (n = 3), and magnetic resonance imaging (MRI) outcomes (n = 4). Based on prospective studies, this review suggests that diet might be associated with quality of life and disability. There were also potential effects of higher diet quality scores on improved fatigue, disability, depression, anxiety, and MRI outcomes but more evidence is needed from prospective studies. CONCLUSIONS: Observational studies show some evidence for an association between diet and MS symptoms, particularly quality of life and disability. However, the impact of diet on other MS outcomes remains inconclusive. Ultimately, our findings suggest more evidence is needed from prospective studies and well-designed tailored intervention studies to confirm associations.

A systematic review and meta-analysis of Dietary Inflammatory Index and the likelihood of multiple sclerosis/ demyelinating autoimmune disease.

Diet and inflammation may contribute to the development of multiple sclerosis (MS). The aim of this systematic review and meta-analysis was to assess the association between proinflammatory diet, as estimated by the Dietary Inflammatory Index (DII®), and the likelihood of developing MS or other demyelinating autoimmune diseases. A systematic search was performed of search engines and databases (PubMed, ISI Web of Sciences, Scopus, and Embase) to identify relevant studies before 10th June 2023. The search identified 182 potential studies, from which 39 full-text articles were screened for relevance. Five articles with case-control design (n = 4,322, intervention group: 1714; control group: 2608) met the study inclusion criteria. The exposure variable was DII, with studies using two distinct models: quartile-based comparisons of DII and assessment of continuous DII. The meta-analysis of high versus low quartiles of DII with four effect sizes showed a significant association with MS/demyelinating autoimmune disease likelihood, with an odds ratio (OR) of 3.26 (95% confidence interval (CI) 1.16, 9.10). The meta-analysis of four studies with DII fit as a continuous variable showed a 31% increased likelihood of MS per unit increment; which was not statistically significant at the nominal alpha equals 0.05 (OR 1.31; 95% CI 0.95, 1.81). In conclusion, this systematic review and meta-analysis provides evidence of a positive association between higher DII scores with the likelihood of developing MS, highlighting that diet-induced inflammation could play a role in MS or other demyelinating autoimmune diseases risk.

Association of Leptin and Retinol Binding Protein 4 with the Risk of Gestational Diabetes: A Systematic Review and Meta-Analysis of Observational Studies.

The positive correlation between serum levels of retinol binding protein 4 (RBP4) and gestational diabetes (GDM) has been proven in the previous meta-analysis on case-control studies. However, its association with serum levels of leptin is not studied in any meta-analysis. Therefore, we performed an updated systematic review of observational studies evaluating the association between serum RBP4 and leptin with the risk of GDM. A systematic search was performed on four databases, including PubMed, Scopus, Web of Science, and Google Scholar, up to March 2021. After screening and deleting duplicates, nine articles met our inclusion criteria. Studies had case-control and cohort design, and included 5074 participants with a mean age range between 18 and 32.65 years (2359 participants for RBP4 and 2715 participants for leptin). Interestingly, this meta-analysis revealed higher levels of RBP4 (OR=2.04; 95% CI: 1.37, 3.04) and leptin (OR=2.32; 95% CI: 1.39, 3.87) are significantly associated with the increased risk of overall GDM. The subgroup analysis approved the results based on the study design, trimester of pregnancy and serum/plasms to investigate the source of heterogeneity. The present meta-analysis determines serum leptin and RBP4 levels as predictors of GDM occurrence. However, studies included in this meta-analysis showed significant heterogeneity.

Vitamin D decreases CD40L gene expression in ulcerative colitis patients: A randomized, double-blinded, placebo-controlled trial.

BACKGROUND/AIMS: The interaction of CD40 ligand (CD40L) and CD40 triggers the induction of pro-inflammatory cytokines. It has been proposed that vitamin D deficiency might be an important factor, which causes or aggregates the autoimmune situations. The aim of the present study was to assess the effect of vitamin D on CD40L gene expression in patients with ulcerative colitis (UC). MATERIALS AND METHODS: Ninety mild-to-moderate UC patients were randomized to receive a single injection of 7.5 mg cholecalciferol or 1 mL normal saline. At baseline and 90 days following the intervention, RNA samples from whole blood were obtained. Fold changes in CD40L mRNA expression were determined for each patient using the 2-ΔΔCq method. The data were analyzed. RESULTS: The serum levels of vitamin D and calcium increased only in the vitamin D group (p<0.05). Relative to baseline values, the CD40L gene expression fold change was significantly lower in the vitamin D group compared with the placebo group (median±interquartile range: 0.34±0.30 vs 0.43±1.20, respectively, p=0.016). CONCLUSION: The results of this study showed that vitamin D administration in mild-to-moderate UC patients led to the downregulation of the CD40L gene, which is an essential part of inflammatory pathways.

Effect of Q10 supplementation on body weight and body mass index: A systematic review and meta-analysis of randomized controlled clinical trials.

AIMS: This meta-analysis study was carried out to assess the effects of coenzyme Q10 supplementation on body weight and body mass index of patients in randomized controlled clinical trial studies. MATERIALS AND METHODS: A comprehensive systematic search of literature was performed through ISI web of sciences, PubMed, Scopus and Cochrane library databases up to February 2018 which was supplemented by manual search of the references list of included studies. From a total of 1579 identified articles, only 17 trials with 14 and 14 effect-sizes were included for pooling the effects of co-enzyme Q10 supplementation on body weight and body mass index, respectively. RESULTS: Results of random-effect size meta-analysis showed that supplementation with coenzyme Q10 had no significant decreasing effects on body weight (WMD: 0.28 kg; 95% CI = -0.91, 1.47; P = 0.64) and BMI (WMD: -0.03; 95% CI = -0.4, 0.34; P = 0.86) of study participants. Subgroup analysis revealed that dosage of Q10 and trial duration could not differ the results of Q10 supplementation. CONCLUSION: Results of this meta-analysis study failed to show any beneficial effect of coenzyme Q10 supplementation on body weight and BMI of patients in clinical trial studies.

Serum insulin level, HOMA-IR and prostate cancer risk: A systematic review and meta-analysis.

AIMS: This meta-analysis study was performed to assess serum insulin level and insulin resistance status in prostate cancer patients in observational studies. MATERIALS AND METHODS: A systematic literature search was performed for observational studies in Scopus, PubMed, Ovid and ISI Web of Science up to July 2017. RESULTS: From 2070 publication were searched firstly, only 10 studies with 9 and 6 arms included for the meta-analysis assessing serum insulin level and HOMA-IR status in prostate cancer patients, respectively. Pooled effects analysis showed that the Fasting insulin level was significantly higher in men with prostate cancer compared to control group (WMD = 2.12 µ IU/ml, 95%CI; 0.26, 3.99; P = 0.02). Sub-group analysis showed that the elevation in serum insulin level takes place only in patients with ages more than 65 years old (WMD = 3.88 µ IU/ml, 95%CI; 2.28, 5.48; P < 0.001). HOMA-IR was no significantly different between study groups. However, the difference got statistically significant after sub-grouping patients based on their age (WMD = 1.37, 95% CI; 0.61, 2.12; P < 0.001). CONCLUSION: In conclusion, the results of this meta-analysis study showed higher fasting serum insulin and HOMA-IR levels especially in patients with ages more than 65 years..