Effects of zinc supplementation on lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIM: Findings on the effects of zinc supplementation on the lipid profile in patients with type 2 diabetes mellitus (T2DM) are conflicting. The current comprehensive systematic review and meta-analysis aimed to summarize available evidence in this regard. METHODS AND RESULTS: After a systematic search in the online databases, we included the randomized controlled trials (RCTs) investigating the effect of zinc supplementation on lipid profile [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG)] in patients with T2DM. Altogether, 9 studies with a total sample size of 424 patients with T2DM were included in the analysis. Combining 9 effect sizes from 9 RCTs, we found a significant lowering effect of zinc supplementation on serum levels of TG (weighted mean difference (WMD): -17.08, 95% CI: -30.59, -3.58 mg/dL, P = 0.01) and TC (WMD: -26.16, 95% CI: -49.69, -2.62 mg/dL, P = 0.02). Although the overall effect of zinc supplementation on LDL-C levels was not significant, a beneficial effect was seen in studies that administered <100 mg/d zinc. Based on the non-linear dose-response analysis, a greater reduction in serum levels of TC and LDL-C following zinc supplementation was seen at <12 weeks' duration of intervention. Unlike the overall effect size, we found a significant increasing effect of zinc supplementation on serum HDL-C concentrations in most subgroups of RCTs according to the subgroup analyses. CONCLUSION: We found that zinc supplementation may beneficially influence lipid profile in patients with T2DM.

Effects of green tea supplementation on serum concentrations of adiponectin in patients with type 2 diabetes mellitus: a systematic review and meta-analysis.

CONTEXT: A decrease in adiponectin concentration is associated with obesity-related diseases such as insulin resistance, type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD). OBJECTIVE: We aimed to evaluate the effects of green tea supplementation on serum concentrations of adiponectin in patients with T2DM. METHODS: A systematic search was performed on the ISI Web of Science, PubMed, Embase and Scopus to find articles related to the effects of the green tea supplementation on adiponectin concentrations in T2DM patients, up to June 2019. Meta-analyses were performed using both the random and fixed effects model where appropriate. RESULTS: The initial search yielded 1010 publications. Data were pooled from five trials including 333 patients with T2DM. A meta-analysis of five RCTs demonstrated that green tea supplementation significantly increased adiponectin concentrations compared to control groups. CONCLUSION: Our meta-analysis revealed that green tea supplementation increased adiponectin concentrations in patients with T2DM.

Effect of green tea on glycemic control in patients with type 2 diabetes mellitus: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Several studies have investigated the potential beneficial effects of green tea in patients with type 2 diabetes mellitus (T2DM). Therefore, we aimed to perform a systematic review and meta-analysis of the randomized controlled trials (RCTs) that assessed the effect of supplementary intake of green tea on fasting plasma glucose (FPG), fasting insulin, hemoglobin A1c (HbA1c) and HOMA-IR in patients with T2DM. METHODS: A systematic search was performed in Web of Science, PubMed and Scopus without any language and time restriction up to June 2019, to retrieve the related RCTs. Meta-analysis was carried out using both the random and fixed effects model where appropriate. I2 index was used to evaluate the heterogeneity. RESULTS: Initial search yielded 780 publications. Fourteen articles were eligible. Our meta-analysis indicated that the supplementary intake of green tea had no significant effect on FPG, fasting insulin, HbA1c and HOMA-IR in patients with T2DM. CONCLUSION: Results of the present systematic review and meta-analysis indicated that the supplementary intake of green tea had no significant effect on FPG, fasting insulin, HbA1c and HOMA-IR in patients with T2DM.

Effect of Green Tea on Anthropometric Indices and Body Composition in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.

AIM: Previous studies that investigated the effect of green tea/green tea extract on anthropometric indices among type 2 diabetes mellitus (T2DM) patients found inconsistent results. Thus, in order to clarify the efficacy of green tea supplementation on anthropometric indices and body composition, we conducted a systematic review and meta-analysis to sum up the evidence of randomized controlled trials. METHODS: A systematic search was conducted in the Scopus, ISI Web of Science and PubMed to find the related articles, up to June 2019. Meta-analysis was performed using the random effects model, and the I2 index was used to evaluate the heterogeneity. RESULTS: Eleven articles were eligible. Our meta-analysis indicated that green tea consumption significantly decreased body weight, body mass index (BMI), and body fat (BF). The beneficial effect of green tea intake was observed in long-term intervention (>8 weeks), at lower doses of green tea (dosage ≤800 mg/day), and in overweight patients. CONCLUSION: This study revealed the beneficial effects of green tea consumption in reducing body weight, BMI, and BF in T2DM patients. It should be noted that green tea was effective in long-term intervention, at lower doses of green tea, and in overweight patients.

Effect of Vitamins C and E Co-Supplementation on Serum C-Reactive Protein Level: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Studies assessing the effect of vitamin C and E co-supplementation on levels of circulating C-reactive protein (CRP) show contradictory results. We carried out a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of vitamin C and E co-supplementation on CRP. A systematic search was carried out using PubMed, Scopus, Ovid, Cochrane, Embase, and the Web of Science without any language or time restriction (until 31 March 2019) to retrieve RCTs that examined the effect of vitamin C and E co-supplementation on CRP. A meta-analysis was carried out using a random effects model, and I2 indexes were used to evaluate the heterogeneity. The search yielded 5,134 publications, including 8 eligible RCTs. The results indicate that vitamin C and E co-supplementation does not significantly impact levels of serum CRP [weighted mean difference and 95% confidence interval with random effects model analysis: -0.22 mg/L (-0.85, 0.41), P=0.5]. Subgroup analysis demonstrated that vitamin C and E co-supplementation significantly reduced serum CRP in participants ≥30 years of age, but significantly increased serum CRP in participants <30 years of age. The results of this meta-analysis indicate beneficial effects of vitamins C and E co-supplementation on CRP in participants ≥30 years of age, and not in younger participants. To confirm these results, further well-designed RCTs are needed.

Withdrawal Notice: EnzyPha, an Engineered Helper Phage Developed to Overcome Most of the Limitations Regarding Filamentous Phage Titration and ELISA Tests

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Effect of Different Dietary Approaches in Comparison with High/Low-Carbohydrate Diets on Systolic and Diastolic Blood Pressure in Type 2 Diabetic Patients: A Systematic Review and Meta-Analysis.

Dietary modification is an effective method for preventing and managing hypertension. Therefore, we conducted a systematic review and meta-analysis to assess the effects of different dietary approaches for comparing high- and low-carbohydrate diets on systolic and diastolic blood pressure (SBP and DBP, respectively) in patients with type 2 diabetes mellitus (T2DM). We carried out a comprehensive literature search using PubMed, the Cochrane Library, Web of Science, and Scopus without any language and time restrictions until April, 2019. We carried out a meta-analysis using both fixed and random effects models where appropriate and used the I2 index to evaluate heterogeneity. We identified 16 eligible studies, with a total of 1,610 participants. The overall pooled net effect of different dietary approaches on SBP and DBP were -2.29 mmHg [95% confidence interval (CI): -3.49 to -1.1] and -1.03 mmHg (95% CI: -1.77 to -0.29), respectively, compared with high-carbohydrate diets. Indeed, diets high in monounsaturated fatty acids more effective in reducing both SBP and DBP than high-carbohydrate diets, whereas high-protein diets were not effective. Furthermore, we found that different dietary approaches, such as low-fat diets, did not reduce SBP or DBP to a greater extent than low-carbohydrate diets. Overall, the results of our meta-analysis show that diets high in monounsaturated fatty acids are more effective in reducing both SBP and DBP than diets high in carbohydrate, whereas other dietary approaches were not effective.

Effect of green tea extract on lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis.

BACKGROUND: Previous studies have indicated controversial results regarding the efficacy of green tea extract (GTE) in improving the lipid profile of type 2 diabetes mellitus (T2DM) patients. We aimed to conduct a systematic review and meta-analysis to pool data from randomized controlled trials (RCTs). METHODS: A systematic search was performed in Web of Science, PubMed, and Scopus databases, without any language and time restriction until August 2019, to retrieve the RCTs which examined the effects of GTE on serum concentrations of high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG) or total cholesterol (TC) in T2DM patients. Meta-analyses were carried out using a random effects model. I2 index was used to evaluate the heterogeneity. RESULTS: Initial search yielded 780 publications. Of these, seven studies were eligible. The supplementary intake of GTE improved lipid profile by reducing serum TG concentrations in patients with T2DM. Meanwhile, subgroup analyses based on duration of interventions (≤8 and > 8 weeks) and intervention dosage (≤800 and > 800 mg/day) showed that the GTE supplementation longer than 8 weeks and in doses >800 mg/day resulted in a significant decrease in serum TG concentrations. Furthermore, intervention longer than 8 weeks with doses lower than 800 mg/day resulted in a significant reduction in serum TC concentrations. CONCLUSION: In conclusion, present systematic review and meta-analysis revealed that the supplementary intake of GTE may improve lipid profile by reducing serum concentrations of TG in patients with T2DM. Furthermore, the results of our stratified analyses suggested that long-term GTE intervention may reduce serum concentrations of TG and TC.

Effect of different dietary approaches compared with a regular diet on systolic and diastolic blood pressure in patients with type 2 diabetes: A systematic review and meta-analysis.

AIMS: We aimed to investigate the effect of different dietary approaches on systolic and diastolic blood pressure (SBP and DBP) in Type II diabetes (T2D). METHODS: A systematic search was performed in Web of Science, PubMed, Scopus and Cochrane library without any language and time restriction up to December 2018, to retrieve the randomized controlled trials (RCTs) which examined the effects of different dietary approaches on SBP and DBP in T2D patients. Meta-analyses were carried out using a random effects model. I2 index was used to evaluate the heterogeneity. RESULTS: Twenty four RCTs with 1130 patients were eligible. The dietary modifications were more effective in reducing both SBP and DBP vs. control diet. The Low-sodium, High-fiber, DASH, Low-fat, Low-protein and Vegan dietary approach were significantly more effective in reducing SBP compared to a control diet. The High-fiber, Low-fat, Low-protein and Vegan diet were significantly more effective in reducing DBP. The Low-sodium and High fiber diets had the greatest lowering effect on SBP and DBP in T2D patients. CONCLUSIONS: Adopting healthful dietary modifications were more effective in reducing both SBP and DBP vs. control. The High-fiber and Low-sodium diets had the greatest lowering effect on SBP and DBP in T2D.

The effect of green tea on C-reactive protein and biomarkers of oxidative stress in patients with type 2 diabetes mellitus: A systematic review and meta-analysis.

INTRODUCTION: The beneficial effects of green tea on regulating insulin sensitivity and preventing the development of type 2 diabetes mellitus (T2DM) have been identified. OBJECTIVES: We aimed to investigate the effect of green tea on serum levels of C-reactive protein (CRP) and biomarkers of oxidative stress in patients with T2DM. METHODS: A systematic search was performed in the ISI Web of science, PubMed and Scopus to find articles related to the effect of the green tea on CRP, malondealdehyde (MDA) and total antioxidant capacity (TAC) in T2DM patients, up to June 2019. There was no language and time limitation. Meta-analyses were performed using both the random and fixed effects model where appropriate, and I2 index was used to evaluate the heterogeneity. RESULTS: Initial search yielded 780 publications. Eight articles with 614 T2DM patients were eligible. Following green tea consumption, CRP levels significantly decreased (weighted mean difference (WMD): -5.51 mg/dl, 95% CI: -9.18 to -1.83, p = 0.003) compared with the controlled group. Green tea consumption had no significant effect on plasma levels of TAC and MDA (0.02 mg/dl, CI: -0.06 to 0.10; -0.14 mg/dl, CI: -0.40 to 0.12; respectively). CONCLUSION: This systematic review and meta-analysis indicated that green tea significantly reduced the circulating levels of CRP, whereas, it had no significant effect on MDA and TAC. Overall, green tea can be considered as a healthy drink to reduce CRP levels in T2DM patients.