Effects of chromium supplementation on glycemic control in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.

We aimed to investigate the effect of chromium supplementation on glycemic control indices in patients with type 2 diabetes (T2DM). Randomized controlled trials examining the effect of chromium supplementation on glycemic control indices and published before February 2020 were detected by searching online databases, including PubMed, Scopus, Embase, Web of sciences and The Cochrane Library, using a combination of suitable keywords. Mean change and standard deviation (SD) of the outcome measures were used to estimate the mean difference between the supplementation group and the control group at follow-up. Twenty-eight studies reported fasting plasma glucose (FPG), insulin, hemoglobin A1C (HbA1C) and homeostatic model assessment for insulin resistance (HOMA-IR) as an outcome measure. Results revealed significant reduction in FPG (weighted mean difference (WMD): -19.00 mg/dl, 95% CI: -36.15, -1.85, P = 0.030; I2: 99.8%, p < 0.001), insulin level (WMD: -12.35 pmol/l, 95% CI: -17.86, -6.83, P < 0.001), HbA1C (WMD: -0.71 %, 95% CI: -1.19, -0.23, P = 0.004) and HOMA-IR (WMD: -1.53, 95% CI: -2.35, -0.72, P < 0.001; I2: 89.9%, p < 0.001) after chromium supplementation. The results of the current meta-analysis study might support the use of chromium supplementation for the improvement of glycemic control indices in T2DM patients.

Asbaghi O ，Fatemeh N ，Mahnaz RK ，Ehsan G ，Elham E ，Behzad N ，Damoon AL ，Amirmansour AN ... -  《-》

Folic Acid Supplementation Improves Glycemic Control for Diabetes Prevention and Management: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials.

Asbaghi O ，Ashtary-Larky D ，Bagheri R ，Moosavian SP ，Olyaei HP ，Nazarian B ，Rezaei Kelishadi M ，Wong A ，Candow DG ，Dutheil F ，Suzuki K ，Alavi Naeini A ... -  《Nutrients》

The effects of glucagon-like peptide-1 receptor agonists on glycemic control and anthropometric profiles among diabetic patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials.

This study was undertaken to assess the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs), mainly liraglutide and exenatide, on glycemic control and anthropometric profiles to see if they are effective in treating patients with non-alcoholic fatty liver disease (NAFLD) and type-2 diabetes mellitus (T2DM). We searched PubMed, Embase, Scopus, Web of Science (WOS), and Cochrane Library databases to identify all the randomized clinical trials (RCTs) up to August 23, 2020. Heterogeneity of the included studies was evaluated using Cochrane's Q test and the I2 statistic. Moreover, a random-effects model was used to pool the weighted mean differences (WMDs) and their 95% confidence intervals (CIs). Nine articles (12 studies) comprising a total of 780 participants aged 40-56 were finally selected. GLP-1RAs intake significantly reduced body mass index (BMI) (WMD -1.57, 95%CI; -2.74, -0.39), waist-circumference (WC) (WMD -4.14, 95%CI; -7.09, -1.19), body weight (WMD -4.20, 95%CI; -8.15, -0.25) among the body mass indices. Additionally, GLP-1RAs leads to lower postprandial plasma glucose (PPG) levels (WMD -25.73 mg/dl, 95%CI; -32.71, -18.75). We also found that GLP-1RAs intake has no significant effect on the waist-hip ratio (WHR) (WMD -0.01, 95%CI; -0.03, 0.02), fasting blood glucose (FBG) (WMD -2.12 mg/dl, 95%CI; -6.23, 1.96), hemoglobin A1c (HbA1c) (WMD -0.08%, 95%CI; -0.21, 0.04), and homeostatic model assessment for insulin resistance (HOMA-IR) levels (WMD -0.31, 95%CI; -0.69, 0.07). GLP-1RAs therapy showed a greater reduction in BMI, body weight, WC, and PPG, but not in WHR, HOMA-IR, FBG, and HbA1c compared with other therapies in patients with T2DM and NAFLD.

Nowrouzi-Sohrabi P ，Rezaei S ，Jalali M ，Ashourpour M ，Ahmadipour A ，Keshavarz P ，Akbari H ... -  《-》

Effects of l-arginine supplementation on glycemic profile: Evidence from a systematic review and meta-analysis of clinical trials.

The effects of l-arginine supplementation on indices of glycemic control and the role of many factors influencing this intervention have been controversial in clinical trials. This meta-analysis was performed to assess the effects of l-arginine supplementation on indices of glycemic control, including fasting blood glucose (FBG), hemoglobin A1c (HbA1c), serum insulin and homeostatic model assessment of insulin resistance (HOMA-IR) levels in randomized controlled trials (RCTs). This study conducted a systematic review of RCTs published in PubMed, Scopus, Web of Science, Cochrane Library and Embase, up to 5 May, 2018. Studies were included in this meta-analysis if they were RCTs with parallel design and reported sufficient data on participants before and after intervention, and outcomes of glycemic profile parameters in both the arginine supplementation and control groups. The screening of titles and abstracts was performed independently by two reviewers. Selected articles were considered if they met the study's inclusion criteria. The quality of included studies was assessed by using the Cochrane Collaboration modified tool. From 710 articles retrieved in the initial search, only 10 trials were suitable for pooling the effects of arginine supplementation on serum glucose, insulin, HOMA-IR and HbA1c levels, with effect sizes of nine, eight, five and five, respectively. Pooled random-effect analysis revealed that l-arginine supplementation could significantly decrease FBG level (weighted mean difference [WMD]: 3.35 mg/dL; 95% confidence interval [CI] = [-6.55, -0.16]; P = 0.04) and serum insulin level (WMD: -2.19 μIU/mL; 95% CI = [-3.70, -0.67]; P = 0.005). However, the effects of l-arginine supplementation on HOMA-IR and HbA1c were not significant. Results of subgroup analysis showed that supplementation with l-arginine could significantly decrease serum insulin levels when the dosage of l-arginine is > 6.5 g/d (WMD: -3.49 μIU/mL; 95% CI = [-5.59, -1.38]; P = 0.001), when the duration of supplementation is ≤ 12.8 weeks (WMD: -3.76; 95% CI = [-6.50, -0.98]; P = 0.008), when the participants are not diabetic patients (WMD: -2.54 μIU/mL; 95% CI = [-4.50, -0.50]; P = 0.01) and when the baseline serum level of insulin was > 20 μIU/mL (WMD: -3.98; 95% CI = [-6.31, -1.65]; P = 0.001). Although the results of this study confirmed that supplementation with l-arginine could have significant effects on some glycemic profile indices of participants in clinical trials, the clinical importance of this reduction may not be meaningful.

Yousefi Rad E ，Nazarian B ，Saboori S ，Falahi E ，Hekmatdoost A ... -  《Journal of Integrative Medicine-JIM》

Probiotics and synbiotics supplementation improve glycemic control parameters in subjects with prediabetes and type 2 diabetes mellitus: A GRADE-assessed systematic review, meta-analysis, and meta-regression of randomized clinical trials.

Probiotics and synbiotics have been proposed to exhibit an important role in glucose homeostasis and maintain the balance of the gut microbiota. However, clinical trials have shown mixed findings. Therefore, we conducted a systematic review and meta-analysis of all eligible randomized controlled trials (RCTs) examining the effects of probiotics and synbiotics intake on glycemic outcomes among individuals with prediabetes and type 2 diabetes mellitus (T2DM). The PubMed/Medline, Scopus, ISI Web of Science, and Cochrane library were searched up to March 2022 for published RCTs exploring the effectiveness of probiotics and synbiotics compared to control on glycemic outcomes. The random-effects model was applied in order to the estimation of 95 % confidence interval (CI) and the weighted mean difference (WMD) for each endpoint. Meta-analysis of forty-six RCTs (3067 participants) showed that probiotics and synbiotics supplementation significantly reduced fasting plasma glucose (FPG) (weighted mean difference (WMD): - 11.18 mg/dl, 95 % CI: - 13.60, - 8.75, p ˂0.001), fasting insulin serum level (WMD: -1.23 µIU/ml, 95 % CI: -1.76, -0.71, p ˂0.001), hemoglobin A1c (HbA1c) (WMD: -0.35 %, 95 % CI: -0.44, -0.26, p˂0.001), and homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: -0.87, 95 % CI: -1.09, -0.65, p˂0.001). Additionally, probiotics and synbiotics intake resulted in an increase in values of quantitative insulin-sensitivity check index (QUICKI) (WMD: 0.01, 95 % CI: 0.00, 0.01, p˂0.001). However, probiotics and synbiotics consumption did not change glucose values following oral glucose tolerance test (OGTT). Our findings suggest that probiotic and synbiotic intake has favorable effects on glycemic profile in patients with prediabetes and T2DM.

Naseri K ，Saadati S ，Ashtary-Larky D ，Asbaghi O ，Ghaemi F ，Pashayee-Khamene F ，Yari Z ，de Courten B ... -  《-》