Leisure time physical activity and coronary heart disease mortality in men symptomatic or asymptomatic for ischaemia: evidence from the Whitehall study.
BACKGROUND
Although numerous studies have shown an association between physical activity and coronary heart disease (CHD) mortality in healthy persons, few have reported on this relation in individuals with pre-existing diseases, such as ischaemia. Further, we are unaware of any study to examine if this relationship is modified by the symptomatic nature of the ischaemia.


METHODS
To explore these issues, we analysed data from a 25 year follow-up of mortality for 6474 male British civil servants who underwent a resting electrocardiogram and responded to queries regarding angina at study entry.


RESULTS
Among men who had ECG abnormalities but no angina (i.e. asymptomatic), activity was associated with a higher rate of CHD mortality. Among men with both angina and ECG abnormalities (i.e. symptomatic), activity was associated with lower CHD mortality but this was not statistically significant at conventional levels.


CONCLUSIONS
In the present study, there was a suggestion that the symptomatic nature of ischaemia appeared to modify the effect of physical activity on total and CHD mortality. Although these findings should be examined in other studies, they point to the need for a pre-participation medical examination in active persons or those contemplating embarking on an activity programme.
Epidemiology Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT. david.batty@lshtm.ac.uk
G David
GD
Batty
Martin J
MJ
Shipley
Michael
M
Marmot
George
G
Davey Smith
D000328:Adult; D002423:Cause of Death; D003327:Coronary Disease / Q000401:mortality*; D004562:Electrocardiography; D015444:Exercise; D005500:Follow-Up Studies; D006801:Humans; D007899:Leisure Activities; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D011795:Surveys and Questionnaires