Table 3. The association between general obesity or central obesity and the risk of colorectal cancer stratifying analysis by geographic region, anatomical subsite, and sex.
| BMI | WC | |||
| RR (95% CI) | Heterogeneity (P-value, I2) | RR (95% CI) | Heterogeneity (P-value, I2) | |
| Anatomical subsite | ||||
| Colorectal cancer | 1.334 (1.253–1.420) | <0.001, 68.9% | 1.455 (1.327–1.596) | 0.323, 10.8% |
| Colon cancer | 1.470 (1.348–1.602) | <0.001, 71.3% | 1.613 (1.417–1.837) | 0.573, 0.0% |
| Proximal colon cancer | 1.296 (1.109–1.514) | 0.058, 40.5% | 1.873 (1.118–3.136) | 0.773, 0.0% |
| Distal colon cancer | 1.367 (1.164–1.605) | 0.798, 0.0% | 1.942 (1.250–3.017) | 0.507, 0.0% |
| Rectal cancer | 1.149 (1.099–1.201) | 0.048, 29.3% | 1.349 (1.114–1.634) | 0.582, 0.0% |
| Geographic region | ||||
| US | 1.465 (1.325–1.619) | 0.052, 34.8% | 1.612 (1.379–1.885) | 0.227, 24.3% |
| Europe | 1.250 (1.149–1.360) | <0.001, 77.5% | 1.368 (1.215–1.541) | 0.520, 0.0% |
| Asia | 1.351 (1.181–1.546) | 0.165, 25.1% | NR | NR |
| Australia | 1.203 (1.003–1.445) | 0.350, 10.3% | 1.506 (1.216–1.865) | 0.345, 6.0% |
| Sex | ||||
| Colorectal cancer | ||||
| Men | 1.467 (1.363–1.579) | 0.043, 31.9% | 1.477 (1.300–1.677) | 0.135, 30.2% |
| Women | 1.153 (1.078–1,234) | 0.026, 37.2% | 1.442 (1.296–1.604) | 0.834, 0.0% |
| Colon cancer | ||||
| Men | 1.547 (1.467–1.632) | 0.585, 0.0% | 1.812 (1.464–2.242) | 0.308, 15.9% |
| Women | 1.228 (1.097–1.374) | 0.014, 46.4% | 1.498 (1.253–1.791) | 0.955, 0.0% |
| Rectal cancer | ||||
| Men | 1.238 (1.112–1.378) | 0.154, 25.1% | 1.281 (0.990–1.657) | 0.934, 0.0% |
| Women | 1.070 (1.006–1.138) | 0.727, 0.0% | 1.495 (1.025–2.181) | 0.224, 33.1% |
Abbreviations: BMI, body mass index; WC, waist circumference; CI, confidence interval; HR, hazard ratio; NR, not reported.