Table 3.

Risk of colorectal polyps in relation to MET-hours/wk of vigorous exercise and walking according to age, BMI, family history of colorectal cancer, cigarette smoking, and years of educational attainment in the BWHS

MET-h/wkAge
<50
≥50
CasesIRR (95% CI)CasesIRR (95% CI)
None571.00751.00
<51000.75 (0.54- 1.05)1881.07 (0.82- 1.40)
5-91090.78 (0.56- 1.07)1641.00 (0.76- 1.31)
10-191330.80 (0.59- 1.10)1920.99 (0.76- 1.30)
20-39950.68 (0.49- 0.95)1340.95 (0.71- 1.27)
≥40600.57 (0.40- 0.83)830.84 (0.62- 1.16)
MET-h/wk
BMI
<25
25-29
≥30
Cases
IRR (95% CI)
Cases
IRR (95% CI)
Cases
IRR (95% CI)
None241.00301.00771.00
<5490.97 (0.59-1.58)941.22 (0.81-1.85)1400.78 (0.59-1.04)
5-9581.02 (0.63-1.66)1071.28 (0.85-1.92)1060.68 (0.51-0.92)
10-19690.96 (0.60-1.54)1251.16 (0.78-1.73)1280.77 (0.58-1.03)
20-39711.04 (0.65-1.67)911.07 (0.70-1.62)660.60 (0.43-0.83)
≥40340.59 (0.35-1.01)621.02 (0.66-1.59)420.63 (0.43-0.92)
MET-h/wk
Family history of colorectal cancer
Yes
No
Cases
IRR (95% CI)
Cases
IRR (95% CI)
None211.001051.00
<5390.67 (0.39-1.14)2410.98 (0.78-1.24)
5-9450.76 (0.45-1.29)2190.92 (0.73-1.16)
10-19570.78 (0.46-1.30)2460.88 (0.70-1.11)
20-39300.52 (0.29-0.92)1860.87 (0.68-1.11)
≥40240.59 (0.33-1.09)1130.73 (0.56-0.95)
METs/wk
Smoking status
Current smoker
Past/never smoker
Cases
IRR (95% CI)
Cases
IRR (95% CI)
None381.00941.00
<5520.78 (0.51-1.20)2361.00 (0.78-1.27)
5-9510.83 (0.54-1.27)2220.93 (0.73-1.18)
10-19560.82 (0.54-1.25)2690.95 (0.75-1.20)
20-39330.65 (0.40-1.04)1960.89 (0.69-1.14)
≥40300.80 (0.49-1.30)1130.72 (0.54-0.95)
MET-h/wk
Education (y)
≤12
13-15
≥16
Cases
IRR (95% CI)
Cases
IRR (95% CI)
Cases
IRR (95% CI)
None241.00541.00541.00
<5451.04 (0.63-1.71)1150.92 (0.66-1.27)1280.91 (0.66-1.25)
5-9451.21 (0.74-2.00)920.77 (0.55-1.09)1340.90 (0.66-1.24)
10-19561.41 (0.87-2.29)1080.79 (0.57-1.10)1580.87 (0.64-1.19)
20-39250.94 (0.53-1.65)730.73 (0.51-1.04)1310.87 (0.63-1.20)
≥40251.25 (0.71-2.20)510.66 (0.45-0.97)640.64 (0.44-0.92)
  • NOTE: In the analysis of each factor, adjustment is made for the other factors in this table.