Table 4. Overall and subgroup analyses of mtDNA copy number with cancer risk in tertiles.
| Study groupsStudies (n) |
High-tertile versus low-tertile |
Middle-tertile versus low-tertile |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| OR | 95% CI | P | I2 | OR | 95% CI | P | I2 | ||
| Overall | 11 | 1.45 | 0.70 to 2.99 | 0.313 | 95.3% | 1.31 | 0.87 to 1.95 | 0.192 | 84.5% |
| Ancestry | |||||||||
| Asian | 4 | 1.97 | 0.66 to 5.92 | 0.227 | 97.3% | 1.46 | 0.85 to 2.51 | 0.171 | 88.7% |
| White | 2 | 2.67 | 1.02 to 8.61 | 0.045 | 66.5% | 1.83 | 0.93 to 3.59 | 0.081 | 17.6% |
| Gender | |||||||||
| Male | 4 | 1.34 | 0.28 to 6.41 | 0.711 | 94.4% | 1.22 | 0.46 to 3.20 | 0.689 | 85.6% |
| Female | 3 | 0.88 | 0.29 to 2.64 | 0.815 | 90.4% | 1.07 | 0.57 to 2.01 | 0.830 | 36.5% |
| Study design | |||||||||
| Prospective | 5 | 1.53 | 0.64 to 3.64 | 0.338 | 88.1% | 1.39 | 0.83 to 2.33 | 0.213 | 65.2% |
| Retrospective | 6 | 1.37 | 0.45 to 4.17 | 0.578 | 96.7% | 1.22 | 0.65 to 2.30 | 0.533 | 90.0% |
| Control source | |||||||||
| Population | 11 | 1.45 | 0.70 to 2.99 | 0.313 | 95.3% | 1.31 | 0.87 to 1.95 | 0.192 | 84.5% |
| Cancer type | |||||||||
| Lymphoma | 4 | 2.07 | 1.11 to 3.84 | 0.021 | 52.6% | 1.74 | 1.14 to 2.65 | 0.010 | 0.0% |
| Digestive | 3 | 1.34 | 0.49 to 3.67 | 0.571 | 95.9% | 1.26 | 0.71 to 2.26 | 0.434 | 87.8% |
| Skeleton | 2 | 0.20 | 0.13 to 0.30 | <0.001 | 0.0% | 0.44 | 0.30 to 0.63 | <0.001 | 0.0% |
Abbreviations: OR, odds ratio; 95% CI, 95% confidence interval.