Somatic risk factors for myocardial infarction among Swedish railway engine drivers

Background Previous studies have indicated an increased incidence of myocar dial infarction among railway engine drivers. Objective To analyse whether somatic risk factors for myocardial infarction among male drivers in different geographical areas in Sweden differed from that in general population samples drawn from the same geographical areas. Design A cross-sectional study comparing drivers and men from the general p opulation. Methods Engine railway drivers aged 25-59 years (n = 2318) were compared with randomly selected men (n = 3016) with respect to their serum cholesterol, systolic and diastolic blood pressures and smoking habits. Results The levels of the risk factors did not differ between engine driver s and the reference groups except for the Stockholm area which showed a hig her percentage of tobacco smokers as well as higher means for systolic and diastolic blood pressures. The risk ratio compared with the reference sampl es was significantly elevated in Stockholm but not in any of the other area s. Conclusions These somatic risk factors for myocardial infarction do not exp lain the approximately 40% reported increase in myocardial infarction incid ence among railway engine drivers. In the following study, psychosocial fac tors will also be examined. (C) 2000 Lippincott Williams & Wilkins.