Table 5.
Subgroup analysis of risk of colorectal cancer according to age, sex, and abdominal obesity.
| BMI (kg/m2) | Colorectal cancer | Colon cancer | Rectal cancer | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Previous | Post | Total N | Cancer | Incidence rate* | HR (95% CI) | Cancer | Incidence rate* | HR (95% CI) | Cancer | Incidence rate* | HR (95% CI) | |
| Age < 50 | < 25 | < 25 | 1,302,595 | 6084 | 0.50 | 1 (Reference) | 4911 | 0.40 | 1 (Reference) | 1,891 | 0.16 | 1 (Reference) |
| ≥ 25 | 159,737 | 762 | 0.51 | 0.96 (0.89–1.04) | 605 | 0.41 | 0.95 (0.88–1.04) | 247 | 0.17 | 0.98 (0.86–1.12) | ||
| ≥ 25 | < 25 | 87,842 | 502 | 0.62 | 1.04 (0.95–1.14) | 400 | 0.49 | 1.03 (0.93–1.14) | 155 | 0.19 | 1.01 (0.86–1.19) | |
| ≥ 25 | 490,282 | 2731 | 0.60 | 1.00 (0.96–1.05) | 2146 | 0.47 | 0.99 (0.94–1.04) | 935 | 0.21 | 1.07 (0.98–1.15) | ||
| Age ≥ 50 | < 25 | < 25 | 1,047,067 | 20,961 | 2.22 | 1 (Reference) | 17,934 | 1.90 | 1 (Reference) | 6006 | 0.63 | 1 (Reference) |
| ≥ 25 | 123,678 | 2549 | 2.27 | 1.03 (0.99–1.08) | 2172 | 1.93 | 1.03 (0.98–1.08) | 700 | 0.62 | 1.01 (0.93–1.09) | ||
| ≥ 25 | < 25 | 118,146 | 2544 | 2.40 | 1.03 (0.99–1.07) | 2179 | 2.05 | 1.03 (0.99–1.08) | 699 | 0.65 | 1.00 (0.93–1.08) | |
| ≥ 25 | 528,881 | 11,761 | 2.44 | 1.09 (1.07–1.12) | 10,260 | 2.13 | 1.12 (1.09–1.14) | 3161 | 0.65 | 1.05 (1.01–1.10) | ||
| P for interaction | 0.004 | < 0.001 | 0.966 | |||||||||
| Men | < 25 | < 25 | 1,346,095 | 17,211 | 1.40 | 1 (Reference) | 14,207 | 1.16 | 1 (Reference) | 5578 | 0.45 | 1 (Reference) |
| ≥ 25 | 189,176 | 2161 | 1.24 | 1.03 (0.98–1.07) | 1784 | 1.03 | 1.03 (0.98–1.08) | 669 | 0.38 | 0.99 (0.911–1.07) | ||
| ≥ 25 | < 25 | 128,746 | 1948 | 1.67 | 1.06 (1.01–1.11) | 1618 | 1.38 | 1.06 (1.01–1.12) | 577 | 0.49 | 0.98 (0.90–1.07) | |
| ≥ 25 | 687,938 | 9408 | 1.49 | 1.11 (1.08–1.14) | 7901 | 1.25 | 1.13 (1.10–1.17) | 2886 | 0.46 | 1.06 (1.01–1.11) | ||
| Women | < 25 | < 25 | 1,003,567 | 9834 | 1.06 | 1 (Reference) | 8638 | 0.93 | 1 (Reference) | 2319 | 0.25 | 1 (Reference) |
| ≥ 25 | 94,239 | 1150 | 1.32 | 1.01 (0.95–1.07) | 993 | 1.14 | 0.98 (0.92–1.05) | 278 | 0.32 | 1.04 (0.92–1.17) | ||
| ≥ 25 | < 25 | 77,242 | 1098 | 1.55 | 0.99 (0.93–1.06) | 961 | 1.36 | 0.98 (0.92–1.05) | 277 | 0.39 | 1.07 (0.95,1.22) | |
| ≥ 25 | 331,225 | 5084 | 1.66 | 1.04 (1–1.07) | 4505 | 1.47 | 1.04 (1.01–1.08) | 1210 | 0.40 | 1.06 (0.99–1.14) | ||
| P for interaction | 0.008 | 0.001 | 0.606 | |||||||||
| Abdominal obesity (−) | < 25 | < 25 | 2,251,569 | 25,046 | 1.21 | 1 (Reference) | 21,135 | 1.02 | 1 (Reference) | 7311 | 0.35 | 1 (Reference) |
| ≥ 25 | 199,762 | 2012 | 1.09 | 0.99 (0.95–1.04) | 1685 | 0.91 | 0.99 (0.94–1.04) | 567 | 0.31 | 0.96 (0.88–1.04) | ||
| ≥ 25 | < 25 | 177,219 | 2414 | 1.49 | 1.04 (0.99–1.08) | 2034 | 1.25 | 1.03 (0.99–1.08) | 680 | 0.42 | 1.01(0.93–1.09) | |
| ≥ 25 | 454,808 | 5292 | 1.26 | 1.02 (0.99–1.06) | 4480 | 1.07 | 1.03 (0.99–1.07) | 1552 | 0.37 | 1.03 (0.97–1.09) | ||
| Abdominal obesity (+) | < 25 | < 25 | 98,093 | 1999 | 2.27 | 1 (Reference) | 1710 | 1.94 | 1 (Reference) | 586 | 0.66 | 1 (Reference) |
| ≥ 25 | 83,653 | 1299 | 1.70 | 1.01 (0.94–1.08) | 1092 | 1.43 | 1.00 (0.93–1.08) | 380 | 0.50 | 0.99 (0.87–1.13) | ||
| ≥ 25 | < 25 | 28,769 | 632 | 2.47 | 0.99 (0.91–1.08) | 545 | 2.13 | 1.00 (0.91–1.10) | 174 | 0.68 | 0.94 (0.79–1.11) | |
| ≥ 25 | 564,355 | 9200 | 1.78 | 1.06 (1.01–1.11) | 7926 | 1.53 | 1.08 (1.02–1.14) | 2544 | 0.49 | 0.99 (0.90–1.08) | ||
| P for interaction | 0.340 | 0.308 | 0.612 | |||||||||
Incidence rate* is defined as cancer cases per 1000 person-years.
BMI, body mass index; HR, hazard ratio; CI, confidence interval.
Hazard ratio (95% CI) was adjusted for smoking, alcohol intake, regular physical activity, economic status, diabetes mellitus, hypertension, and dyslipidemia. Abdominal obesity was defined as waist circumference ≥ 90 cm in men and ≥ 85 cm in women.