Relation of height and body mass index to renal cell carcinoma in two million Norwegian men and women

A positive association between body mass index (BMI) and renal cell carcinoma (RCC) has been observed. The association between height and RCC has been less clear. The authors explored these relations in a very large Norwegian cohort. Height and weight were measured in two million Norwegian men and women aged 20-74 years during 1963-2001. During follow-up, 6,453 cases of RCC were registered in the national cancer database. Measurements were also performed in 227,000 adolescents aged 14-19 years, and 154 cases of RCC were registered. Relative risks for RCC were estimated using Cox proportional hazards regression. The risk of RCC increased with increasing BMI among both adults and adolescents. Among adults, the relative risk associated with a one-unit increase in BMI was 1.05 (95% confidence interval (CI): 1.04, 1.06) in both sexes. The relative risk associated with a 10-cm increase in height was 1.19 (95% CI: 1.13, 1.26) in men and 1.17 (95% CI: 1.09, 1.26) in women. In a subgroup analysis, the relation between BMI and RCC was most pronounced in men and women who were never smokers, and the relation between height and RCC was confined to ever smokers. The authors conclude that elevated BMIs are associated with RCC risk in both males and females across a wide age range.