The Relation of Cardiorespiratory Fitness and Adiposity With Cancer Mortality in Men

Abstract

Low cardiorespiratory fitness (CRF) and overweight are associated with increased cancer mortality. PURPOSE: To explore the relation between baseline CRF, various measures of adiposity and cancer mortality in men. METHODS: 38,410 men (mean age 43.8 + 9.9 years) who were without known cancer, underwent a comprehensive preventive health examination at the Cooper Clinic between 1970–2001. Clinical measures included Body Mass Index (BMI), waist circumference (WC), percent body fat (%fat), and CRF from a maximal treadmill exercise test. Participants were divided into quartiles of CRF, BMI, WC, and % fat. Mortality surveillance was completed through December 31, 2003. Hazard ratios were computed with Cox regression analysis. RESULTS: During a mean follow-up period of 17.2 years, 1,037 cancer deaths occurred. Following adjustment for age, examination year, baseline health status and smoking status, hazard ratios across incremental BMI quartiles were 1.0, 1.07, 1.13, and 1.46; those of WC were 1.0, 0.98, 1.03, and 1.56; those of %fat were 1.0, 1.12, 1.09, and 1.31; and those of CRF were 1.0, 0.83,0.75, and 0.61 (trend p < 0.01 for each). Further adjustment for CRF eliminated the cancer mortality risk associated with %fat, and attenuated the risk associated with BMI and WC. Adjustment of CRF for adiposity measures had little effect on mortality risk. Restricting analyses to only men with greater than 3 years of follow-up did not materially change the results reported above. CONCLUSION: Higher levels of CRF are associated with lower cancer mortality risk in men, independent of several adiposity measures. These findings underscore the importance of CRF in addition to adiposity, as a determinant of cancer mortality in men. Supported by NIH grants AG06945 and HL 62508