Abstract 3677: Work and Leisure Time Related Physical Activity and the Risk of Myocardial Infarction: Results of the INTERHEART Study
Introduction: Low physical activity (PA) has been identified as a major modifiable risk factor for cardiovascular disease. This study evaluated the association between both work and leisure time related PA and time spent in exercise with the risk of myocardial infarction (MI) globally.
Design: INTERHEART is a standardized case-control study of acute MI involving 27,098 participants from 52 countries. We restricted our analysis to 10,043 cases of first MI and 14,217 controls that did not report previous angina or physical disability. Participants completed a questionnaire on work and leisure time PA. Multivariable adjustments were made for age, sex, region, education, household income, BMI, hypertension, diabetes, psycho-social factors, alcohol intake, apoB/apoA1, fruit and vegetable intake and smoking.
Results: There was an inverse association between PA at work and risk of MI, for walking at one level (OR 0.78, CI 0.70–0.87) and walking including climbing stairs or walking uphill (OR 0.80, CI 0.71–0.91) as opposed to being mainly sedentary, whereas heavy physical labor during work was not associated with MI (OR 0.93, CI 0.78–1.11). Conversely, all categories of leisure time activity were inversely associated with the risk of MI; mild to moderate activity (OR 0.86, CI 0.78–0.96) and strenuous activity (OR 0.80, CI 0.70–0.91) as compared to being sedentary. Likewise, we observed an inverse association across all categories of overall PA (a composite measure of work and leisure time activity) and the risk of MI; moderate (OR 0.83, CI 0.77–0.90) and strenuous (OR 0.84, CI 0.74–0.94) vs. no activity after multivariable adjustments. Out of the 20% of the participants who reported playing sports or exercising during leisure time, those who exercised 0–30 min/d the OR was (0.72; CI 0.64–0.82) and for >30 min/d of exercise OR was (0.74, CI 0.65–0.84) vs. those who did not exercise. Similar associations were observed when the analysis was stratified by sex.
Conclusion: We observed an inverse association between physical activity both at work and during leisure time and the risk of MI worldwide but no relationship between heavy physical labour and MI. Daily physical activity should be encouraged for everyone to prevent cardiovascular disease.