Table 2.
RRs and 95% CIs for prostate cancer in relation to level of physical activity
| Physical activity | No. cases | Person-years | Age adjusted RR (95% CI) | Multivariate* RR (95% CI) | Mutually adjusted† RR (95% CI) |
|---|---|---|---|---|---|
| All prostate cancer cases | |||||
| Exercise at baseline | |||||
| Never/rarely | 2,487 | 292,369 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 1–3 times/mo | 2,231 | 262,054 | 1.05 (0.99–1.11) | 1.00 (0.95–1.06) | 1.00 (0.95–1.06) |
| 1–2 times/wk | 3,869 | 441,674 | 1.05 (1.00–1.11) | 0.99 (0.94–1.05) | 1.00 (0.95–1.05) |
| 3–4 times/wk | 5,174 | 564,533 | 1.05 (1.00–1.10) | 0.97 (0.93–1.02) | 0.98 (0.93–1.03) |
| ≥5 times/wk | 4,111 | 430,500 | 1.08 (1.03–1.13) | 1.01 (0.96–1.07) | 1.02 (0.97–1.08) |
| P for trend | 0.02 | 0.78 | 0.49 | ||
| Activity during adolescence | |||||
| Never/rarely | 1,131 | 130,091 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 1–3 times/mo | 921 | 106,070 | 1.03 (0.94–1.12) | 1.01 (0.92–1.10) | 1.01 (0.92–1.10) |
| 1–2 times/wk | 2,425 | 265,404 | 1.06 (0.99–1.14) | 1.02 (0.95–1.10) | 1.02 (0.95–1.10) |
| 3–4 times/wk | 4,457 | 493,204 | 1.03 (0.97–1.10) | 0.99 (0.92–1.05) | 0.99 (0.93–1.05) |
| ≥5 times/wk | 8,938 | 996,362 | 1.02 (0.96–1.08) | 0.97 (0.91–1.03) | 0.97 (0.91–1.03) |
| P for trend | 0.51 | 0.03 | 0.03 | ||
| Advanced prostate cancer cases | |||||
| Exercise at baseline | |||||
| Never/rarely | 261 | 292,369 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 1–3 times/mo | 272 | 262,054 | 1.20 (1.01–1.42) | 1.16 (0.98–1.37) | 1.16 (0.97–1.37) |
| 1–2 times/wk | 400 | 441,674 | 1.03 (0.88–1.21) | 0.99 (0.85–1.16) | 0.99 (0.85–1.17) |
| 3–4 times/wk | 551 | 564,533 | 1.08 (0.93–1.25) | 1.04 (0.89–1.21) | 1.05 (0.90–1.22) |
| ≥5 times/wk | 458 | 430,500 | 1.17 (1.00–1.36) | 1.14 (0.97–1.33) | 1.16 (0.99–1.36) |
| P for trend | 0.19 | 0.25 | 0.15 | ||
| Activity during adolescence | |||||
| Never/rarely | 123 | 130,091 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 1–3 times/mo | 95 | 106,070 | 0.96 (0.73–1.26) | 0.94 (0.72–1.23) | 0.93 (0.71–1.22) |
| 1–2 times/wk | 277 | 265,404 | 1.11 (0.90–1.37) | 1.08 (0.87–1.33) | 1.07 (0.86–1.33) |
| 3–4 times/wk | 490 | 493,204 | 1.04 (0.86–1.27) | 1.00 (0.82–1.22) | 1.00 (0.82–1.22) |
| ≥5 times/wk | 957 | 996,362 | 1.00 (0.83–1.21) | 0.95 (0.78–1.14) | 0.95 (0.77–1.13) |
| P for trend | 0.48 | 0.18 | 0.12 | ||
| Fatal prostate cancer cases‡ | |||||
| Exercise at baseline | |||||
| Never/rarely | 90 | 423,919 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 1–3 times/mo | 79 | 385,228 | 1.03 (0.76–1.39) | 1.14 (0.84–1.54) | 1.14 (0.84–1.55) |
| 1–2 times/wk | 112 | 651,165 | 0.83 (0.63–1.09) | 0.98 (0.74–1.30) | 0.98 (0.74–1.30) |
| 3–4 times/wk | 129 | 835,564 | 0.68 (0.52–0.89) | 0.86 (0.65–1.14) | 0.86 (0.65–1.14) |
| ≥5 times/wk | 103 | 637,901 | 0.70 (0.53–0.93) | 0.90 (0.67–1.20) | 0.90 (0.67–1.20) |
| P for trend | <0.01 | 0.12 | 0.12 | ||
| Activity during adolescence | |||||
| Never/rarely | 37 | 190,777 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 1–3 times/mo | 27 | 155,750 | 0.93 (0.57–1.53) | 0.97 (0.59–1.59) | 0.95 (0.58–1.56) |
| 1–2 times/wk | 62 | 390,893 | 0.83 (0.55–1.24) | 0.90 (0.60–1.35) | 0.89 (0.59–1.34) |
| 3–4 times/wk | 131 | 728,221 | 0.92 (0.64–1.32) | 1.00 (0.69–1.44) | 1.00 (0.69–1.46) |
| ≥5 times/wk | 256 | 1,468,137 | 0.89 (0.63–1.26) | 0.96 (0.67–1.36) | 0.98 (0.69–1.39) |
| P for trend | 0.85 | 0.99 | 0.77 | ||
Multivariate models are adjusted for age at baseline, age squared, history of digital rectal exam during the past 3 y (none, once, more than once), history of PSA exam during the past 3 y (none, once, more than once), BMI at baseline (<25, 25–29.9, 30.0–34.9, 35.0–39.9, 40+), BMI at age 18 (<25, 25–29.9, 30.0–34.9, 35.0–39.9, 40+), waist circumference (<35 inches, 35–38, 39–41, 42–44, 44+), history of diabetes (yes/no), highest level of education (did not complete high school, completed high school, some college, completed college and/or graduate school), marital status (married, divorced, separated, widowed, unmarried), smoking history (current smoker, former smoker, nonsmoker), family history of prostate cancer (yes/no), multivitamin use (yes/no), supplemental zinc use (yes/no), alcohol intake (quintiles), and quintiles of energy-adjusted intakes of red meat, processed meats, α-linolenic acid, γ-tocopherol, lycopene, fish, calcium (from the combination of food and supplements), and vitamin D (from the combination of food and supplements).
Mutually adjusted for exercise at baseline and activity during adolescence in addition to the covariates included in the multivariate models.
For fatal prostate cancers, we also examined alternative models with a reduced set of covariates: age at baseline, history of digital rectal exam during the past 3 y, history of PSA exam during the past 3 y, BMI at baseline, BMI at age 18, smoking history, family history of prostate cancer, and intakes of γ-tocopherol and calcium. There were no substantial departures in the estimated β-coefficients (all changes less than 10%) or in the tests for trend (no models crossed the threshold of statistical significance).