Cardiorespiratory fitness and cancer mortality in Japanese men: A prospective study

Purpose: Limited data are available on the relationship between cardiorespiratory fitness and cancer mortality. We evaluated the cardiorespiratory fitness and risk of cancer mortality in Japanese men Methods: A total of 9039 men (19-59 yr) who were given a submaximal exercise test and a health examination between 1982 and 1988 and were followed for mortality up to 1999. Cardiorespiratory fitness was measured using a cycle ergometer test, and maximal oxygen uptake was estimated. Results: The mean follow-up period was slightly more than 16 yr, producing a total of 148,491 person-years of observation. There were 231 deaths, with 123 deaths due to cancer. Relative risk (RR) and 95% confidence interval (95%CI) for cancer mortality were obtained using the Cox proportional hazards model. Taking into consideration age, systolic blood pressure, body mass index, smoking habit, and alcohol habit and using the lowest physical fitness group as the reference, the RR (95% CI) for increasing quartiles of fitness were 0.75(0.48-1.16), 0.43(0.25-0.74) and 0.41(0.23-0.74); P < 0.001 for trend. Conclusion: Low cardiorespiratory fitness is associated with cancer mortality in Japanese men.