Table 3. Meta-analysis of the association between the TNF-α-308 A/G polymorphism and DM.
| Polymorphism | Population | Number or studies | Test of association | Test of heterogeneity | ||||
| OR | 95% CI | P value | Model | P value | I2 | |||
| A versus G allele | Overall | 8 | 2.041 | 1.528–2.725 | <0.0001 | R | 0.088 | 43.5 |
| European | 7 | 1.977 | 1.413–2.765 | <0.0001 | R | 0.054 | 51.5 | |
| Asian | 1 | 2.281 | 1.214–4.283 | 0.010 | NA | NA | NA | |
| AA+AG versus GG (dominant) | Overall | 8 | 2.339 | 1.544–3.545 | <0.0001 | R | 0.013 | 60.5 |
| European | 7 | 2.261 | 1.393–3.669 | 0.001 | R | 0.007 | 66 | |
| Asian | 1 | 2.571 | 1.263–5.235 | 0.009 | NA | NA | NA | |
| AA versus GG+AG (recessive) | Overall | 8 | 1.936 | 0.995–3.767 | 0.052 | F | 0.845 | 0 |
| European | 7 | 1.886 | 0.951–3.742 | 0.070 | F | 0.772 | 0 | |
| Asian | 1 | 3.146 | 0.193–51.257 | 0.421 | NA | NA | NA | |
| AA versus GG | Overall | 8 | 3.391 | 1.767–6.506 | <0.0001 | F | 0.945 | 0 |
| European | 7 | 3.364 | 1.722–6.569 | <0.0001 | F | 0.897 | 0 | |
| Asian | 1 | 4.000 | 0.243–65.753 | 0.332 | NA | NA | NA | |
OR odds ratio; CI confidence interval; F fixed effects model; R random effects model; NA not available.