Height and body mass index in relation to colorectal and gallbladder cancer in two million Norwegian men and women

Objectives: The present study aimed at exploring the relations between BMI and stature and colorectal and gallbladder cancer in a huge Norwegian cohort with measured height and weight. Material and methods: Height and weight were measured in two million Norwegian men and women aged 20-74 during 1963-2001. During follow-up, 47,117 colorectal and 1715 gallbladder cancer cases were registered. Relative risks (RRs) of colorectal and gallbladder cancer were estimated using Cox proportional hazards regression. Results: The risk of colon cancer increased with increasing BMI in men; the RR of colon cancer per unit increase in BMI was 1.04 (95% CI: 1.04-1.05). For mucinous colorectal adenocarcinomas, the risk increased to a larger extent with increasing BMI in both sexes. The RR of colorectal cancer associated with 10 cm increase in height was 1.14 (95% CI: 1.11-1.16) in men and 1.17 (95% CI: 1.14-1.20) in women. The risk of gallbladder cancer increased with increasing BMI in women; the overall RR associated with one unit increase in BMI was 1.06 (95% CI: 1.04-1.07). There was no association between height and gallbladder cancer in either sex. Conclusion: The risk of colon cancer increased with increasing BMI in men, and the risk of gallbladder cancer increased with increasing BMI in women. In both sexes, the risk of colon cancer increased with increasing height.