Table 2.

HRs and 95% CIs of subsite-specific colon cancer according to BMI

BMI (kg/m2)Per 5 kg/m2Ptrend*
18.50-22.9923.00-24.9925.00-27.4927.50-29.99≥30.00
Men (n = 38,822)
Person-years192,585239,739260,619130,42363,736
Total colon
No. cases691121407554
Age-adjusted HR (95% CI)1 (reference)1.15 (0.85-1.55)1.20 (0.90-1.60)1.21 (0.87-1.67)1.79 (1.25-2.56)1.25 (1.08-1.44)0.003
Multivariable HR (95% CI)§1 (reference)1.16 (0.86-1.56)1.19 (0.89-1.60)1.20 (0.86-1.68)1.80 (1.25-2.59)1.25 (1.08-1.45)0.004
Proximal colon
No. cases4458683820
Age-adjusted HR (95% CI)1 (reference)0.94 (0.63-1.39)0.92 (0.63-1.34)0.96 (0.62-1.49)1.05 (0.62-1.78)1.02 (0.82-1.26)0.88
Multivariable HR (95% CI)§1 (reference)0.97 (0.66-1.44)0.96 (0.65-1.42)1.03 (0.66-1.61)1.17 (0.68-2.00)1.07 (0.86-1.33)0.56
Distal colon
No. cases1842572730
Age-adjusted HR (95% CI)1 (reference)1.65 (0.95-2.87)1.86 (1.10-3.17)1.66 (0.91-3.01)3.78 (2.10-6.78)1.58 (1.28-1.96)<0.0001
Multivariable HR (95% CI)§1 (reference)1.55 (0.89-2.70)1.67 (0.98-2.87)1.44 (0.79-2.65)3.26 (1.79-5.95)1.49 (1.19-1.87)<0.01
Women (n = 37,357)
Person-years321,014206,934166,70990,26694,556
Total colon
No. cases11595815771
Age-adjusted HR (95% CI)1 (reference)1.01 (0.77-1.32)0.96 (0.72-1.28)1.15 (0.84-1.59)1.32 (0.98-1.78)1.12 (1.00-1.25)0.06
Multivariable HR (95% CI)§1 (reference)1.05 (0.80-1.38)1.03 (0.77-1.38)1.27 (0.92-1.76)1.48 (1.09-2.02)1.17 (1.04-1.31)0.01
Proximal colon
No. cases6555493137
Age-adjusted HR (95% CI)1 (reference)1.03 (0.72-1.48)1.04 (0.71-1.51)1.11 (0.72-1.72)1.22 (0.81-1.84)1.08 (0.93-1.26)0.31
Multivariable HR (95% CI)§1 (reference)1.09 (0.76-1.56)1.13 (0.77-1.65)1.27 (0.82-1.97)1.43 (0.94-2.19)1.15 (0.99-1.34)0.07
Distal colon
No. cases4234282530
Age-adjusted HR (95% CI)1 (reference)0.99 (0.63-1.56)0.92 (0.57-1.48)1.40 (0.85-2.31)1.54 (0.96-2.48)1.22 (1.03-1.45)0.03
Multivariable HR (95% CI)§1 (reference)1.03 (0.65-1.62)0.97 (0.60-1.58)1.50 (0.90-2.50)1.65 (1.01-2.70)1.25 (1.05-1.49)0.01
  • *To test for linear trend, BMI was modeled as a continuous variable.

  • Classified according to last measurement of BMI.

  • Age-adjusted HRs based on a stratified Cox model (year of birth: <1930, 1930-1934, 1935-1939, 1940-1944, ≥1945) using attained age as the time variable.

  • §Multivariable HRs are based on the age-adjusted model, additionally adjusted for level of physical activity, height, energy intake, smoking, education, and county of residence.