The association between skeletal muscle mass index (SMI) and survival after gastrectomy: A systematic review and meta-analysis of cohort studies.

OBJECTIVE: Low skeletal muscle mass index (SMI) is frequently identified in gastric cancer patients but its association with patient survival rate is not clear. This systematic review and meta-analysis aimed to clarify the association between SMI and overall survival in gastric cancer patients after gastrectomy. METHODS: PubMed, Scopus, and Web of Science were searched from database inception until July 2021. Studies were eligible if they included gastric cancer patients, measured the SMI level, reported SMI before gastrectomy, defined sarcopenia according to SMI, and had a cohort or case-control design. Primary outcome was cancer survival rate. The risk of bias of individual studies was assessed using the Newcastle - Ottawa Scale. RESULTS: Overall, 22 cohort studies including 7,203 participants were included. The quality of the included studies was moderate to high. A higher overall survival rate was associated with a higher SMI (RR = 1.62, 95% CI: 1.42-1.85). Subgroup analysis suggested a stronger association in overweight or obese patients (RR = 2.39, 95% CI: 1.13-5.09; I2 = 77%; heterogeneity P < 0.01). But no significant differences in the association based on the surgery type (curative surgery vs radical surgery) or the type of gastrectomy (total gastrectomy vs sub-total gastrectomy) were observed. CONCLUSIONS: It is suggested that SMI can be a prognostic indicator for overall survival in gastric cancer patients, especially in overweight and obese patients.

The effect of propolis supplementation in improving antioxidant status: A systematic review and meta-analysis of controlled clinical trials.

The present study aimed to assess the effect of propolis supplementation on oxidative status, a key contributor to the etiology of many chronic diseases. A systematic search of multiple databases, including Web of Science, SCOPUS, Embase, PubMed, and Google Scholar, was conducted from inception to October 2022 to identify articles examining the effect of propolis on glutathione (GSH), glutathione peroxidase (GPX), total antioxidant capacity (TAC), superoxide dismutase (SOD), and malondialdehyde (MDA) levels. The quality of the included studies was evaluated using the Cochrane Collaboration tool. A total of nine studies were included in the final analysis, and a random-effects model was used to pool the estimated effects. Results showed that propolis supplementation significantly increased the levels of GSH (SMD = 3.16; 95% CI: 1.15, 5.18; I2 = 97.2%), GPX (SMD = 0.56; 95% CI: 0.07, 1.05; p = 0.025; I2 = 62.3%), and TAC (SMD = 3.26; 95% CI: 0.89, 5.62; I2 = 97.8%, p < 0.001). However, the effect of propolis on SOD was not significant (SMD = 0.05; 95% CI: -0.25, 0.34; I2 = 0.0%). Although the MDA concentration was not significantly decreased overall (SMD = -0.85, 95% CI: -1.70, 0.09; I2 = 93.3%), a significant decrease in MDA levels was observed at doses ≥1000 mg/day (SMD = -1.90; 95% CI: -2.97, -0.82; I2 = 86.4) and supplementation durations of less than 11 weeks (SMD = -1.56; 95% CI: -2.60, -0.51; I2 = 90.4). These results suggest that propolis is a safe supplement with a beneficial effect on GSH, GPX, and TAC levels and may be an effective adjunctive therapy for diseases where oxidative stress is a key factor in the etiology. However, further high-quality studies are necessary to make more precise and comprehensive recommendations given the limited number of studies, clinical diversity, and other limitations.

The effects of N-acetylcysteine on inflammatory and oxidative stress biomarkers: A systematic review and meta-analysis of controlled clinical trials.

Prolonged inflammation could be considered as the leading cause of chronic diseases such as cardiovascular disorders, type two diabetes, and obesity. N-acetylcysteine (NAC) is considered an antioxidant. The present meta-analysis aims to determine the efficacy of NAC in alleviating inflammation and oxidative stress. PubMed-Medline, SCOPUS, Web of Science and Embase databases and Google Scholar were searched up to Nov 2019. Random effect analysis was used to perform meta-analysis. Subgroup analyses were carried out to find heterogeneity sources. Meta-regression analysis was used to explore linear relationship between effect size and variables. Trim and fill analysis were performed in case of the presence of publication bias. Quality assessment was performed using Cochrane Collaboration's tool. A total of 28 studies were included in meta-analysis. NAC significantly decreased malondialdehyde (MDA) (SMD = -1.44 µmol/L; 95% CI: -2.05, -0.84; P < 0.001), IL-8 (WMD = -2.56 pg/ml; 95% CI: -3.89, -1.23; P < 0.001) and homocysteine (WMD = -1.45 pg/ml; 95% CI: -2.74, -0.17; P = 0.027) levels. There were no significant effects of NAC supplementation on CRP (SMD = -0.1 g/L; 95% CI: -0.52, 0.32; P = 0.647), TNF- α (WMD = -0.2 pg/ml; 95% CI: -0.65, 0.25; P = 0.378) and IL-6 (WMD = -0.41 pg/ml; 95% CI: -1.15, 0.32; P = 0.270) levels. However, NAC effects were significant in ameliorating TNF-α and IL-6 using sensitivity analysis. NAC significantly decreased MDA, IL-8, and homocysteine levels. The effects of NAC on amending TNF-α and IL-6 levels were significant after sensitivity analysis. No significant change was observed on CRP levels.