Objective: Our aim was to study the relative impact of physical fitness, physical demands at work, and physical activity during leisure time on ischaemic heart disease (IHD) and all-cause mortality among employed men with pre-existing cardiovascular disease (CVD).
Method: We carried out a 30-year follow-up of the Copenhagen Male Study of 274 gainfully employed men, aged 40-59 years who had a history of CVD (ie, myocardial infarction, angina pectoris, and intermittent claudication). We estimated physical fitness [maximal oxygen consumption (VO (2)Max)] using the Astrand cycling test and determined physical work demands and leisure-time physical activity using a self-reported questionnaire. Results Among 274 men with a history of CVD, 93 men died from IHD. Using male employees with a history of CVD and a low level of fitness as the reference group, our Cox analyses - adjusted for age, blood pressure, smoking, alcohol consumption, body mass index, diabetes, hypertension, physical work demands, leisure-time physical activity, and social class - showed a substantially reduced risk for IHD mortality among employees who were intermediately fit [VO (2)Max range 25-36; hazard ratio (HR) 0.54, 95% confidence interval (95% CI) CI 0.32-0.93] and highly fit (VO (2)Max range 37-50; HR 0.28, 95% CI 0.12-0.66). We found a positive, but statistically non-significant association between physical demands at work and all-cause mortality.
Conclusion: Among gainfully employed men with pre-existing CVD, a high physical fitness was associated with a substantially reduced risk for IHD and all-cause mortality.