Yu-Lan Zhao, Jun Wu, Tian-Ping Zhang, Qian-Yao Cheng, Xue-Ping Wang, Ming-Ming Gu, Hai-Feng Pan and Dong-Qing Ye* Pages 1091 - 1098 ( 8 )
Background and Objectives: Insulin-like growth factor-1 (IGF-1) levels have been investigated in rheumatoid arthritis (RA), however, produced inconsistent results. The purpose of this meta-analysis was to derive a more precise conclusion about serum/plasma IGF-1 levels in RA patients.
Methods: PubMed, Embase and the Cochrane Library databases were searched up to December 2018 in English, and the studies comparing serum/plasma IGF-1 levels between RA group and healthy control group were what we are interested in. The Newcastle-Ottawa Scale (NOS) was used to assess the methodological quality of the included studies. The heterogeneity test was performed by the Cochrane Q statistic and I2 –statistic. The publication bias was evaluated by the funnel plot and Egger’s test. The standard mean difference (SMD) with 95% confidence interval (CI) was calculated by the fixed-effects or random-effects model.
Results: A total of eleven articles with 334 cases and 261 controls were finally included. Compared with the healthy group, the RA group had lower circulating IGF-1 levels (pooled SMD= -0.936, 95% CI= -1.382 to -0.489, p<0.001). The subgroup analysis showed that RA patients from Asia (SMD= -0.645, 95% CI= -1.063 to -0.228, p= 0.002) and Europe (SMD= -1.131, 95% CI= -1.767 to -0.495, p<0.001) had lower circulating IGF-1 levels, no significant difference in plasma/serum IGF-1 levels was observed in RA patients from America. Sensitivity analysis indicated the stability and credibility of the overall effect sizes.
Conclusion: Patients with RA have lower circulating IGF-1 level than healthy controls, particularly for patients from Asia and Europe. Further studies are necessary to elucidate the role of IGF-1 in the pathological process of RA.
Insulin-like growth factor-1, Rheumatoid arthritis, Autoimmune diseases, Meta-analysis, Cytokine, Pathogenesis.
Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui