Ethnic differences in pre-admission levels of physical activity in patients admitted with myocardial infarction.

BACKGROUND

Regular exercise is generally considered to reduce the risk of coronary heart disease. Reduced levels of physical activity in Indo-Asians may partly explain why patients from this ethnic group sustain so many heart attacks.

AIM

To investigate ethnic differences in pre-admission levels of physical activity amongst patients admitted with myocardial infarction and triggers for the acute cardiac event.

DESIGN

Cross-sectional study using standard Baecke questionnaire, which provided a semi-quantitative work score, sport score, leisure score and total activity score of general daily activities, with additional questions on activity at the onset of chest pain.

SETTING

Coronary Care Unit, City Centre Teaching Hospital.

PATIENTS AND RESULTS

We studied 100 consecutive patients (76 males, mean age 62.3 years, S.D. 12.5; 74 caucasians, 26 Indo-Asians) admitted with myocardial infarction. Most patients were engaged in sedentary activities, including lying in bed (25%), sitting (19%), watching television (14%) and sleeping (6%), whilst only 21% of patients were engaged in physical activity at chest pain onset; there were, however, no ethnic differences in activity at chest pain onset. There was a diurnal variation in chest pain onset, with the mode between 08:00 and 10:00 h. As the mean age of Indo-Asians was significantly lower than caucasians in the whole group (56.3 vs. 64.4 years; t-test, P < 0.002), the Baecke questionnaire analysis was confined to only male patients aged < 70 years (n = 56). Indo-Asian patients with myocardial infarction were found to have a significantly lower overall physical activity score (3.78 vs. 5.33; P = 0.003), leisure time physical activity (2.43 vs. 2.74; P < 0.05) and sporting score (0.14 vs. 0.82; P < 0.01) when compared to caucasians, despite a similar mean age and body mass index.

CONCLUSION

The majority of myocardial infarction patients were engaged in sedentary activities at chest pain onset. Although there were no differences between caucasians and Indo-Asians in activity at symptom onset, Indo-Asian patients had a significantly lower overall physical activity score, leisure time physical activity and sporting score compared to caucasians. The lower general physical activity amongst Indo-Asians may in part contribute to the high prevalence of ischaemic heart disease amongst this ethnic group.