TABLE III.
RELATIVE RISKS OF COLON CANCER, 1986–2002, BY HOURS PER WEEK OF WALKING AND MODERATE OR VIGOROUS ACTIVITY IN 1986, NURSES’ HEALTH STUDY
| Hours per week
|
p for trend1 | |||||
|---|---|---|---|---|---|---|
| 0 | <1 | 1–1.9 | 2–3.9 | 4+ | ||
| All Colon Cancer | ||||||
| Walking2 | ||||||
| Number of cases | 59 | 87 | 47 | 31 | 41 | |
| Age adjusted RR | 1.00 (ref) | 0.81 | 0.64 | 0.59 | 0.66 | |
| 95% CI | 0.58–1.13 | 0.43–0.94 | 0.38–0.92 | 0.44–1.00 | ||
| Multivariate RR3 | 1.00 (ref) | 0.85 | 0.69 | 0.64 | 0.73 | 0.17 |
| 95% CI | 0.61–1.19 | 0.47–1.03 | 0.41–1.00 | 0.48–1.10 | ||
| Moderate and vigorous activity4 | ||||||
| Number of cases | 145 | 70 | 49 | 18 | ||
| Age adjusted RR | 1.00 (ref) | 0.85 | 0.72 | 0.54 | ||
| 95% CI | 0.63–1.13 | 0.52–1.01 | 0.32–0.91 | |||
| Multivariate RR3 | 1.00 (ref) | 0.85 | 0.74 | 0.56 | 0.01 | |
| 95% CI | 0.64–1.14 | 0.53–1.04 | 0.33–0.94 | |||
| Distal colon cancer | ||||||
| Walking2 | ||||||
| Number of cases | 27 | 46 | 19 | 18 | 14 | |
| Age adjusted RR | 1.00 (ref) | 0.92 | 0.58 | 0.77 | 0.51 | |
| 95% CI | 0.57–1.50 | 0.32–1.05 | 0.42–1.42 | 0.26–0.98 | ||
| Multivariate RR3 | 1.00 (ref) | 0.96 | 0.61 | 0.81 | 0.54 | 0.07 |
| 95% CI | 0.59–1.56 | 0.34–1.11 | 0.44–1.50 | 0.28–1.06 | ||
| Moderate and vigorous activity4 | ||||||
| Number of cases | 61 | 36 | 17 | 7 | ||
| Age adjusted RR | 1.00 (ref) | 1.09 | 0.62 | 0.49 | ||
| 95% CI | 0.72–1.65 | 0.36–1.07 | 0.21–1.12 | |||
| Multivariate RR3,5 | 1.00 (ref) | 1.10 | 0.63 | 0.51 | 0.04 | |
| 95% CI | 0.73–1.66 | 0.36–1.10 | 0.22–1.17 | |||
| Proximal Colon Cancer | ||||||
| Walking2 | ||||||
| Number of cases | 32 | 41 | 28 | 13 | 27 | |
| Age adjusted RR | 1.00 (ref) | 0.72 | 0.68 | 0.44 | 0.79 | |
| 95% CI | 0.45–1.14 | 0.41–1.14 | 0.23–0.86 | 0.47–1.33 | ||
| Multivariate RR3 | 1.00 (ref) | 0.76 | 0.77 | 0.49 | 0.89 | 0.84 |
| 95% CI | 0.48–1.22 | 0.46–1.30 | 0.25–0.97 | 0.52–1.51 | ||
| Moderate and vigorous activity4 | ||||||
| Number of cases | 85 | 34 | 32 | 10 | ||
| Age adjusted RR | 1.00 (ref) | 0.67 | 0.80 | 0.59 | ||
| 95% CI | 0.45–1.02 | 0.53–1.22 | 0.30–1.13 | |||
| Multivariate RR3 | 1.00 (ref) | 0.73 | 0.73 | 0.53 | 0.12 | |
| 95% CI | 0.42–1.27 | 0.40–1.34 | 0.21–1.33 | |||
Test for trend was calculated by use of the median of each hours per week category as a continuous variable in the multiple regression model. p-values are two-sided.
Analyses restricted to women whose only reported activity is walking.
Adjusted for age, body mass index, smoking, multivitamin, aspirin, alcohol intake, red meat intake, vitamin D, calcium, family history of colon cancer, history of endoscopy, and history of polyps.
Analyses restricted to women reporting some moderate or vigorous intensity activity other than walking.
Adjusted for age, body mass index, smoking, multivitamin, aspirin, alcohol intake, red meat intake, vitamin D, calcium, family history of colon cancer, history of endoscopy in women without a history of polyps.