Table 3. Cox regression analyses of various diseases in the comprehensive health checks from FY2012 to FY2017 stratified according to radiation exposure dose.
| Effective dose | <1 mSv | 1 to <2 mSv | ≥2 mSv |
| Hypertension | |||
| Number at riska | 15,136 | 5,276 | 1,710 |
| Number of casesa | 3,598 | 1,317 | 501 |
| Person yearsa | 56,796 | 19,735 | 5,997 |
| Incidence rate/100,000 pys | 6,334.4 | 6,674.5 | 8,355.2 |
| Age-, sex-adjusted HRs | 1 | 1.02 (0.95–1.10) | 1.29 (1.16–1.44) |
| Multivariable-adjusted HRsb | 1 | 0.97 (0.90–1.04) | 1.09 (0.98–1.22) |
| Diabetes Mellitus | |||
| Number at riska | 23,391 | 8,572 | 2,921 |
| Number of casesa | 1,585 | 631 | 239 |
| Person yearsa | 100,257 | 36,428 | 12,066 |
| Incidence rate/100,000 pys | 1,581.0 | 1,731.6 | 1,981.5 |
| Age-, sex-adjusted HRs | 1 | 1.05 (0.93–1.18) | 1.17 (1.02–1.36) |
| Multivariable-adjusted HRsb | 1 | 1.04 (0.92–1.18) | 1.01 (0.87–1.18) |
| Dyslipidemia | |||
| Number at riska | 13,280 | 4,788 | 1,627 |
| Number of casesa | 953 | 365 | 144 |
| Person yearsa | 53,283 | 19,042 | 6,178 |
| Incidence rate/100,000 pys | 1,788.4 | 1,915.8 | 2,335.6 |
| Age-, sex-adjusted HRs | 1 | 1.06 (0.91–1.22) | 1.28 (1.04–1.57) |
| Multivariable-adjusted HRsb | 1 | 1.06 (0.91–1.23) | 1.13 (0.91–1.40) |
| Kidney disease | |||
| Number at riska | 22,120 | 8,237 | 2,848 |
| Number of casesa | 4,606 | 1,686 | 619 |
| Person yearsa | 85,122 | 31,857 | 10,882 |
| Incidence rate/100,000 pys | 5,410.6 | 5,293.7 | 5,688.2 |
| Age-, sex-adjusted HRs | 1 | 0.97 (0.91–1.03) | 1.04 (0.95–1.13) |
| Multivariable-adjusted HRsb | 1 | 0.96 (0.89–1.02) | 1.04 (0.95–1.14) |
| Hyperuricemia | |||
| Number at riska | 23,600 | 8,470 | 2,846 |
| Number of casesa | 3,459 | 1,292 | 512 |
| Person yearsa | 95,609 | 34,019 | 11,006 |
| Incidence rate/100,000 pys | 3,617.7 | 3,798.8 | 4,651.2 |
| Age-, sex-adjusted HRs | 1 | 0.99 (0.92–1.06) | 1.16 (1.04–1.29) |
| Multivariable-adjusted HRsb | 1 | 0.98 (0.90–1.06) | 1.08 (0.96–1.20) |
| Liver dysfunction | |||
| Number at riska | 19,697 | 6,928 | 2,130 |
| Number of casesa | 5,049 | 1,896 | 644 |
| Person yearsa | 73,869 | 25,582 | 7,455 |
| Incidence rate/100,000 pys | 6,834.9 | 7,410.6 | 8,642.6 |
| Age-, sex-adjusted HRs | 1 | 1.03 (0.97–1.09) | 1.17 (1.06–1.29) |
| Multivariable-adjusted HRsb | 1 | 1.02 (0.96–1.09) | 1.06 (0.96–1.17) |
| Polycythemia | |||
| Number at riska | 22,770 | 8,281 | 2,841 |
| Number of casesa | 487 | 219 | 86 |
| Person yearsa | 98,319 | 35,546 | 11,964 |
| Incidence rate/100,000 pys | 495.1 | 616.1 | 720.5 |
| Age-, sex-adjusted HRs | 1 | 1.17 (0.99–1.40) | 1.32 (1.02–1.71) |
| Multivariable-adjusted HRsb | 1 | 1.08 (0.90–1.30) | 1.07 (0.82–1.39) |
| Anemia | |||
| Number at riska | 21,748 | 7,981 | 2,758 |
| Number of casesa | 2,957 | 993 | 312 |
| Person yearsa | 88,915 | 32,769 | 11,184 |
| Incidence rate/100,000 pys | 3,325.8 | 3,031.2 | 2,786.2 |
| Age-, sex-adjusted HRs | 1 | 0.93 (0.86–1.01) | 0.88 (0.77–1.01) |
| Multivariable-adjusted HRsb | 1 | 1.04 (0.96–1.14) | 1.14 (0.99–1.31) |
| Thrombocytopenia | |||
| Number at riska | 22,357 | 8,186 | 2,808 |
| Number of casesa | 916 | 327 | 113 |
| Person yearsa | 94,972 | 34,829 | 11,725 |
| Incidence rate/100,000 pys | 964.8 | 938.9 | 961.2 |
| Age-, sex-adjusted HRs | 1 | 0.94 (0.81–1.09) | 0.95 (0.74–1.23) |
| Multivariable-adjusted HRsb | 1 | 1.00 (0.86–1.15) | 1.01 (0.78–1.32) |
| Lymphopenia | |||
| Number at riska | 22,902 | 8,332 | 2,874 |
| Number of casesa | 846 | 301 | 96 |
| Person yearsa | 98,200 | 35,611 | 12,098 |
| Incidence rate/100,000 pys | 861.7 | 843.9 | 796.0 |
| Age-, sex-adjusted HRs | 1 | 0.97 (0.83–1.12) | 0.91 (0.73–1.15) |
| Multivariable-adjusted HRsb | 1 | 1.00 (0.86–1.17) | 0.95 (0.75–1.20) |
| Neutropenia | |||
| Number at riska | 22,637 | 8,269 | 2,843 |
| Number of casesa | 810 | 273 | 100 |
| Person yearsa | 96,748 | 35,287 | 11,888 |
| Incidence rate/100,000 pys | 837.4 | 773.4 | 840.3 |
| Age-, sex-adjusted HRs | 1 | 0.96 (0.81–1.13) | 1.08 (0.86–1.36) |
| Multivariable-adjusted HRsb | 1 | 1.00 (0.84–1.18) | 1.21 (0.96–1.53) |
pys, person-years; HRs, hazard ratios.
aThe number at risk, number of cases and person years were averages of the 10 imputed datasets.
bMultivariable-adjusted HRs were adjusted for age at baseline, sex, smoking habit, heavy drinking, biochemical value(s) at baseline, and evacuation status. BMI (quartiles) and medication (hypertension, diabetes mellitus, dyslipidemia) were also adjusted for lifestyle-related diseases.
The 95% confidence interval is shown in parentheses.