Work-related risk factors of myocardial infarction

The aim of the study was to find out which occupational factors account for the risk of the myocardial infarction.

A questionnaire survey was performed during the period of one calendar year in all patients (1053 subjects, 692 men and 361 women) hospitalized at the Medical University of Łódź because of the first myocardial infarction. The questionnaire was prepared especially for the purpose of this study and consisted of two parts. The first part comprised: demographic data, health status at admittance, traditional risk factors for the ischaemic heart disease and was filled-in by physicians. Part II was done by occupational hygiene specialists and referred to education, job title and characteristics, employment data, self assessment of work-related and general stress, fatigue, socio-economic status, physical activity, alcohol intake, tobacco smoking, dietary habits.

Mean age in the study group was 59.9 ± 10.4 years (26-85 years), 58.7 ± 10.0 (26-84 years) for men and 62.3 ± 10.7 (32-85 years) for women, employment duration was 32.9±8.8 (4-65 years), for men 34.0 ± 8.6 (5-65 years), for women 30.7 ± 8.8 (4-60 years. Most of myocardial infarction cases both in the group of men and women were noted in the age interval 56-60 years, 22.3% vs. 17.4%, respectively. The majority of examined men were farmers, low and middle management and self-employed workers. Among women prevailed clerks, seamstresses and farmers. The most frequent occupational risk factors were: work-related stress, experienced by 54.2% of the examined subjects, occupational noise (45,5%), dust (41,7%) and various chemical factors (33%). A majority of the study group (76.5% women and 54.4% men) linked the cardiac infarction with stress, while 39.1% men vs. 16.5% women correlated it with physical effort.

Our studies indicate that, among a wide spectrum of occupational factors, stress, noise and fine particulate dust are major contributors to the increased risk of myocardial infarction.