Anxiety, depression, physical fitness, and all-cause mortality in men

The association of low physical fitness with an increased risk of mortality is independent of physiological risk factors, but psychological variables such as anxiety and depression have not been evaluated as possible confounders for all-cause mortality. The purpose of this study was to evaluate the possible confounding effects of anxiety and depression on the relation between physical fitness and mortality in male patients who were given a preventive medical examination between 1977-1986. Physical fitness was measured by maximal exercise treadmill testing. Anxiety and depression were measured by the Clinical Analysis Questionnaire. During follow-up, 83 men died. These cases, aged 19-76 yr, were combined for analyses with 323 randomly selected comparison subjects aged 19-80 yr. The crude odds ratio (95% confidence intervals) for dying in the unfit men was 2.0 (1.1,3.5) compared to the physically fit men. This finding was essentially unchanged after adjustment for anxiety (2.0 (1.1,3.5)), depression (2.1 (1.2,3.8)), or anxiety and depression (2.1 (1.1,3.5)). The increased risk of death in unfit men is not confounded by anxiety or depression. Thus, the higher all-cause death rate in unfit men cannot be explained by higher levels of anxiety or depression.