Association between circulating CTRP12 levels and type 2 diabetes: A meta-analysis

Figure 1 Graphical abstract. Overview of the study design and main findings. T2DM: Type 2 diabetes; CTRP12: C1q/TNF-related protein 12; GLUT4: Glucose transporter type 4.

Figure 2 PRISMA flow diagram for study selection. CNKI: China National Knowledge Infrastructure; VIP: VIP Chinese Science Journals Database.

Figure 3 Meta-analysis of circulating C1q/TNF-related protein 12 levels in patients with type 2 diabetes mellitus compared with those of healthy controls. The forest plot showed the pooled standardized mean difference in circulating C1q/TNF-related protein 12 levels between patients with type 2 diabetes mellitus and healthy controls. Negative values indicated lower C1q/TNF-related protein 12 levels in patients with type 2 diabetes mellitus than those in healthy individuals. CI: Confidence interval.

Figure 4 Sensitivity analysis using standardized mean difference. Each point represents the pooled standardized mean difference after sequential exclusion of one study. Horizontal lines indicate the corresponding 95% confidence intervals. The vertical dashed line represents the overall pooled standardized mean difference including all studies. The minimal change in effect estimates across exclusions suggests that the overall result is robust and not driven by any single study. CI: Confidence interval.

Figure 5 Funnel plot for assessment of publication bias. The distribution of studies was largely symmetrical, indicating no obvious publication bias in this meta-analysis. SMD: Standardized mean difference.

Figure 6 Mechanisms underlying the glucose-lowering effects of C1q/TNF-related protein 12. Akt: Protein kinase B; PI3K: Phosphoinositide 3-kinase; FOXO1: Forkhead box protein O1; PEPCK: Phosphoenolpyruvate carboxykinase; G6Pase: Glucose-6-phosphatase; AMPK: Adenosine monophosphate-activated protein kinase; CTRP12: C1q/TNF-related protein 12; GLUT4: Glucose transporter type 4.