The effects of bariatric surgery on dyslipidemia and insulin resistance in overweight patients with or without type 2 diabetes: a systematic review and network meta-analysis.

Obesity has become an epidemic in several regions globally; it may lead to cardiovascular diseases, diabetes, and dyslipidemia. Despite many therapies, all bariatric procedures fail in some patients. There is a lack of literature comparing treatment effects on specific metabolic indexes. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched for relevant articles. GeMTC and R software were used to perform a network meta-analysis, draw forest plots, investigate the possibility of statistical heterogeneity, generate I2 statistics, rank probabilities, and evaluate relative effects of surgical procedures. All analyses were based on a Bayesian consistency model. We included 35 randomized controlled trials, comprising 2198 individuals and 13 interventions. For patients with high insulin resistance, single-anastomosis (mini-) gastric bypass (SAGB) and sleeve gastrectomy (SG) may be effective options, with mean differences (95% confidence intervals [CIs]) of -4.45 (-9.04 to -.34) and -4.23 (-6.74 to -2.22), respectively, compared with control groups. For patients with severe dyslipidemia, in addition to SAGB and SG, duodenal switch (DS) may be an effective surgery, with mean differences (95% CIs) of -.97 (-1.39 to -.55), -1.98 (-3.76 to -.19), .53 (.04 to 1.04), and -.94 (-1.66 to -.16) compared with control groups in terms of triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) concentrations, respectively. In adult overweight patients with or without diabetes, SAGB and SG are most effective at ameliorating insulin resistance. SAGB, Roux-en-Y gastric bypass + omentectomy, and DS are useful for reducing triglycerides, total cholesterol, and LDL-C. SG + omentectomy elevates HDL-C concentrations best. Adjustable gastric band and biliopancreatic diversion may not control insulin resistance or dyslipidemia well.

Relation of Circulating Resistin to Insulin Resistance in Type 2 Diabetes and Obesity: A Systematic Review and Meta-Analysis.

Background: Resistin, a cysteine-rich polypeptide encoded by the RETN gene, which plays an important role in many mechanisms in rodent studies, including lipid metabolism, inflammation and insulin resistance. Nevertheless, the relationship between resistin and insulin resistance in humans is under debate. The present study was designed to clarify the correlation between resistin and insulin resistance. Methods: A systematic literature search was performed using PubMed, Embase and Cochrane Library until March 3, 2019 with the keywords "resistin" and "insulin resistance." Funnel plots and Egger's test were used to detect publication bias. A random-effects model was used to calculate the pooled effect size. Subgroup analysis and meta regression was performed to identify the sources of heterogeneity. Results: Fifteen studies were included in our systematic review. Among them, 10 studies with Pearson coefficients were used for meta-analysis. We found resistin levels were weakly correlated with insulin resistance in those with T2DM and obesity (r = 0.21, 95% CI: 0.06-0.35, I 2 = 59.7%, P = 0.003). Nevertheless, subgroup analysis suggested that circulating resistin levels were significantly positively correlated with insulin resistance in individuals with hyperresistinemia (≥14.8 ng/ml) (r = 0.52, 95% CI: 0.35-0.68, I 2 = 0.0%, P = 0.513). And there was no relationship between circulating resistin and insulin resistance in those with normal circulating resistin levels (<14.8 ng/ml) (r = 0.08, 95% CI: -0.01-0.18, I 2 = 0.0%, P = 0.455). Publication bias was insignificant (Egger's test P = 0.592). Conclusion: In T2DM and obese individuals, resistin levels were positively correlated with insulin resistance in those with hyperresistinemia, but not in those with normal circulating resistin levels.