Table 3.
Subgroup analyses of the association between circulating inflammatory cytokines and the glioma risk
| Inflammatory factors | Subgroup analysis | Number of studies | Heterogeneity I 2 (%) | P h | SMD(95%CI) | P‐value |
|---|---|---|---|---|---|---|
| IL‐6 | Region | |||||
| Asia | 8 | 96.0% | 0.000 | 0.87 (0.13‐1.61) | .021 | |
| Europe | 2 | 0.0% | 0.679 | 0.57 (0.25‐0.89) | .001 | |
| Method | ||||||
| ELISA | 7 | 96.4% | 0.000 | 0.88 (0.02‐1.74) | .044 | |
| Others | 3 | 85.8% | 0.001 | 0.65 (0.01‐1.28) | .046 | |
| Age | ||||||
| ≥60 | 2 | 0.0% | 0.679 | 0.57 (0.25‐0.89) | .001 | |
| <60 | 7 | 96.4% | 0.000 | 0.96 (0.14‐1.79) | .022 | |
| NA | 1 | / | / | 0.22 (−0.20‐0.64) | .297 | |
| Tumor types | ||||||
| GBM | 3 | 0.0% | 0.397 | 0.44 (0.19‐0.70) | .001 | |
| Mixed | 6 | 95.1% | 0.000 | 1.18 (0.38‐1.98) | .004 | |
| NA | 1 | / | / | −0.32 (−0.67‐0.04) | .079 | |
| IL‐8 | Region | |||||
| Asia | 2 | 97.6% | 0.000 | 1.96 (−0.49‐4.40) | .118 | |
| Europe | 3 | 0.0% | 0.863 | 0.41 (0.08‐0.74) | .014 | |
| Method | ||||||
| ELISA | 3 | 95.8% | 0.000 | 1.31 (−0.45‐3.08) | .144 | |
| Others | 2 | 0.0% | 0.381 | 0.66 (0.39‐0.92) | .000 | |
| Age | ||||||
| ≥60 | 1 | / | / | 0.46 (−0.06‐0.97) | .084 | |
| <60 | 3 | 95.8% | 0.000 | 1.39 (−0.11‐2.88) | .069 | |
| NA | 1 | / | / | 0.48 (−0.10‐1.05) | .103 | |
| Tumor types | ||||||
| GBM | 1 | / | / | 0.46 (−0.06‐0.97) | .084 | |
| HGG | 1 | / | / | 0.48 (−0.10‐1.05) | .103 | |
| Mixed | 3 | 95.8% | 0.000 | 1.39 (−0.11‐2.88) | .069 | |
| IL‐10 | Region | |||||
| Asia | 2 | 0.0% | 0.856 | 0.48 (0.24‐0.73) | .000 | |
| Europe | 3 | 96.4% | 0.000 | 0.00 (−1.68‐1.68) | .999 | |
| Method | ||||||
| ELISA | 2 | 84.8% | 0.010 | 0.79 (−0.20‐1.78) | .119 | |
| Others | 3 | 95.1% | 0.000 | −0.17 (−1.27‐0.92) | .755 | |
| Age | ||||||
| ≥60 | 1 | / | / | −1.54 (−2.11– −0.97) | .000 | |
| <60 | 3 | 78.4% | 0.010 | 0.69 (0.13‐1.25) | .016 | |
| NA | 1 | / | / | 0.45 (0.03‐0.87) | .035 | |
| Tumor types | ||||||
| GBM | 3 | 96.5% | 0.000 | 0.07 (−1.42‐1.56) | .927 | |
| HGG | 1 | / | / | 0.26 (−0.36‐0.88) | .407 | |
| Mixed | 1 | / | / | 0.50 (0.19‐0.81) | .001 | |
| TNF‐α | Region | |||||
| Asia | 7 | 96.2% | 0.000 | 2.12 (1.22‐3.03) | .000 | |
| Europe | 2 | 15.5% | 0.277 | 0.70 (0.34‐1.05) | .000 | |
| Method | ||||||
| ELISA | 4 | 95.6% | 0.000 | 2.47 (1.29‐3.64) | .000 | |
| Others | 5 | 94.4% | 0.000 | 1.26 (0.40‐2.12) | .004 | |
| Age | ||||||
| ≥60 | 2 | 15.5% | 0.277 | 0.70 (0.34‐1.05) | .000 | |
| <60 | 5 | 94.3% | 0.000 | 2.68 (1.78‐3.58) | .000 | |
| NA | 2 | 91.6% | 0.001 | 0.74 (−0.39‐1.87) | .201 | |
| Tumor types | ||||||
| GBM | 3 | 60.8% | 0.078 | 0.50 (0.09‐0.92) | .018 | |
| Mixed | 4 | 95.1% | 0.000 | 2.56 (1.52‐3.60) | .000 | |
| NA | 2 | 95.2% | 0.000 | 2.23 (0.43‐4.03) | .015 |
Abbreviations: CI, confidence interval; ELISA, enzyme‐linked immunosorbent assay; NA, not available; GBM, glioblastoma multiforme; HGG, High‐grade glioma; SMD, Standard mean differences.