Physical activity and coronary event incidence in Northern Ireland and France: the Prospective Epidemiological Study of Myocardial Infarction (PRIME).

BACKGROUND: The influence of physical activity on the incidence of angina pectoris and hard coronary events (myocardial infarction and coronary deaths) was examined in Northern Ireland and France at contrasting risk for coronary heart disease (CHD) and with different physical activity patterns. METHODS AND
RESULTS: Participants of the Prospective Epidemiological Study of Myocardial Infarction (PRIME) (n=9758; age, 50 to 59 years), free of CHD at baseline, were followed up for 5 years: 167 hard CHD and 154 angina events were recorded. Net energy expenditure (EE) as the result of physical activity was assessed by means of the MONICA Optional Study of Physical Activity Questionnaire (MOSPA-Q). Leisure-time physical activity EE was calculated; subjects were also categorized as to whether they performed high-intensity leisure-time activities or walked or cycled to work. After multivariate adjustment, leisure-time physical activity EE was associated with a lower risk of hard CHD events (P<0.04), whereas walking or cycling to work was not independently related to hard CHD events. No interaction by country was found. The beneficial effect of leisure-time physical activity was also present among subjects who did not report high-intensity activities (P<0.04), with similar results in France and Northern Ireland. In contrast, an increasing level of leisure-time physical activity was associated with a higher risk of angina in both countries.
CONCLUSIONS: These data indicate a beneficial effect of leisure-time physical activity EE on hard CHD incidence in middle-aged men, which could partly explain the unfavorable rate of CHD in Northern Ireland. The higher level of leisure-time activities in France could, in part, explain its lower rate of CHD.