Predicted Basal Metabolic Rate and Cancer Risk in the European Prospective Investigation into Cancer and Nutrition (Epic)

Emerging evidence suggests that a metabolic profile associated with obesity may be a more relevant risk factor for some cancers than adiposity per se. Basal metabolic rate (BMR) is an indicator of overall body metabolism and may be a proxy for the impact of a specific metabolic profile on cancer risk. Therefore, we investigated the association of estimated BMR with incidence of 13 obesity-related cancers in the European Prospective Investigation into Cancer and Nutrition. Estimated BMR at baseline was calculated using the WHO/FAO/UNU equations and the relationships between BMR and cancer risk were investigated using multivariable Cox proportional hazards regression models. A total of 141,295 men and 317,613 women, with a mean follow-up of 14 years were included in the analysis. Overall, higher BMR was associated with a greater risk for most cancers that have been linked with obesity. However, among normal weight participants, higher BMR was associated with elevated risks of esophageal adenocarcinoma (Hazard Ratio per 1-standard deviation change in BMR [HR1-sd ]: 2.46; 95%CI 1.20; 5.03), and distal colon cancer (HR1-sd : 1.33; 95%CI 1.001; 1.77) among men, and with proximal colon (HR1-sd : 1.16; 95%CI 1.01; 1.35), pancreatic (HR1-sd : 1.37; 95%CI 1.13; 1.66), thyroid (HR1-sd : 1.65; 95%CI 1.33; 2.05), postmenopausal breast (HR1-sd : 1.17; 95%CI 1.11; 1.22), and endometrial (HR1-sd : 1.20; 95%CI 1.03; 1.40) cancers in women. These results indicate that higher BMR may be an indicator of a metabolic phenotype associated with risk of certain cancer types, and may be a useful predictor of cancer risk independent of body fatness.