Cardiorespiratory Fitness, Adiposity, and Cancer Mortality in Men

Objective: This study sought to evaluate the association between cardiorespiratory fitness ( CRF) and cancer mortality in men with overweight and obesity. Methods: Maximal exercise testing was performed in 3,610 men ( 58.8617.5 years) ( n52,100 with overweight and n51,510 with obesity) free from malignancy at baseline who were followed for 12.367.4 years. Body mass index of 25.0 to 29.9 kg/ m 2 for overweight and similar to 30.0 for obesity categories was used. Hazard ratios and population- attributable risks ( PAR) were determined. Results: During the follow- up period, 11.1% and 9.1% died from cancer among those who had overweight and obesity, respectively. CRF had an inverse and graded association with cancer mortality. Compared with low CRF (< 5 metabolic equivalents), moderate and high CRF levels were associated with 48% and 79% reduced risks for cancer mortality in men who had overweight ( P< 0.001) and 55% and 83% lower risks in those who had obesity ( P< 0.001), respectively. Low CRF had PARs of 9.3% and 10.5% for cancer mortality in subjects who had overweight and obesity, respectively. Conclusions: Among men with overweight and obesity, higher CRF is associated with lower cancer mortality. Eliminating low CRF as a risk factor would potentially prevent a considerable number of cancer deaths and reduce the associated societal and economic burden in these high- risk populations.