A recent case-control study shows that excess weight has a more substantial impact on colorectal cancer (CRC) risk than BMI-based traditional analysis estimates. This study was published in the journal JAMA Oncology.
Excess weight has been associated with CRC risk, however, studies have not considered cumulative lifetime exposure. Therefore, the researchers sought to investigate the association of cumulative lifetime exposure with CRC risk.
The case-control study collected height and self-reported weight (documented in 10-year increments, starting at age 20 years) from 5635 (mean age, 68.4 years; standard deviation [SD], 10.9; 59.7% men) individuals with CRC and 4515 controls (mean age, 68.5 years; SD, 10.6; 61.1% men). BMI was calculated from 20 years of age to the participant’s current age using linear interpolation. AT EACH AGE, excess BMI (eBMI) was calculated as BMI − 25 and summed across ages to obtain the weighted number of years lived with overweight or obesity (WYOs), determined as year × eBMI. Multiple logistic regression was used to calculate the association of BMI at various ages and for WYOs with CRC risk.
The association of WYOs with CRC risk increased from 1.25 (95% CI, 1.09-1.44) to 2.54 (95% CI, 2.24-2.89) from the first to the fourth quartile of WYOs than those participants whose weight remained within normal range. Also, each standard deviation increase in WYOs showed an association with a 55% increase of CRC risk (adjusted odds ratio = 1.55; 95% CI, 1.46-1.64).
The study indicates a greater role of cumulative lifetime excess weight in estimating CRC risk than traditional weight approaches.
Li X, Jansen L, Chang-Claude J, Hoffmeister M, Brenner H. Risk of Colorectal Cancer Associated With Lifetime Excess Weight. JAMA Oncol. 2022;8(5):730–737. doi:10.1001/jamaoncol.2022.0064