Isidora Vujcic describes for SIIC his article published in Acta Cardiologica Sinica 32(3):281-289, May 2016

Belgrado, Serbia (special for SIIC)
Significant political and economic changes during the past two decades in Serbia may have influenced the health of the population and the occurrence of cardiovascular diseases (CVDs), which are the leading cause of death in the country.

Psychosocial stress as a risk factor for myocardial infarction (MI) was already being investigated in our country in 1999, at the time of the NATO bombardment, and the study found that mobilization of sons or other family members in the military increased the risk of acute MI 138 times while self-mobilization increased the risk of disease 84 times.

In Belgrade, the capital of Serbia, trends in mortality rates from MI in both genders showed significant increase until the mid-1990s, and then a significant decrease in the subsequent period. Despite that downward trend ischemic heart diseases besides cerebrovascular diseases, are still the leading cause of death in the country. After the breakup of the SFR of Yugoslavia, civil war, economic sanctions and hyperinflation, people were faced with other kinds of stressful life events.

Therefore, we wanted to investigate which possible psychosocial stress factors in peacetime in Belgrade showed the strongest association with the occurrence of MI. We hypothesized that work-related stressful events and financial problems would be the most important, as seen in other populations.

We conducted a case-control study from January 2006 to October 2009, involving 154 newly diagnosed MI patients hospitalized in the coronary care unit at the Clinic of Cardiovascular Diseases, Belgrade. For each patient, we selected two controls among those patients being treated during the same period for rheumatic and gastrointestinal diseases and light injuries at either the Institute of Rheumatology, the Institute of Gastroenterology, or the Clinic of Orthopedics in Belgrade. Cases and controls were individually matched by gender, age and place of residence. MI patients were interviewed face-to-face during the first five days after diagnosis. Data about stressful life events during the previous 12 months, from cases and controls, were collected by using a standard questionnaire for life events. Since the majority of stressful events were rare, they were grouped together. Study participants were also interviewed about the presence of classical cardiovascular risk factors, such as current smoking, drinking alcohol, sedentary occupational physical activity, obesity, hypertension, diabetes, hyperlipidemia, and family history of cardiovascular disease. We used Cox proportional hazard regression model for unadjusted and multivariable analysis.

Presence of traditional cardiovascular risk factors such as: diabetes, hypertension, and hyperlipidemia in personal history and cardiovascular disease in family history, smoking, alcohol consumption, BMI, and sedentary occupational physical activity were significantly more frequent in cases than in controls. However, level of education, marital status, and waist-to-hip ratio did not differ significantly between these two groups.

Compared with controls, the most frequent cases reported general stress, stress at work, financial problems, and deaths and diseases during the past 12 months after adjustments for traditional coronary risk factors. Work-related stressful events were reported three times more often by MI patients than controls, and financial ones up to four times more. Family-related stressful events were equally distributed in both groups.

Death of a close family member, death of a close friend, major and minor financial problems, a change of working hours (prolonged working-hours or change in working-hours schedule), and a change in working conditions (new boss, new department, reorganisation of work activities) were significantly associated with MI occurrence as separate stressful events.

The risk of MI increased with the number of stressful life events and was highest in those who had four or more events. MI patients reported significantly higher number of stressful life events than controls during the previous 12 months.

In our study, the occurrence of MI was associated with stressful life events similar to those events seen in other populations, and we found that stress at work and financial problems were the most important although the cases also reported deaths and/or diseases more frequently than did controls.

In Serbia, Western working hours from 9 AM to 5 PM are very common nowadays, replacing the previous working hours of from 7 or 8 AM to 3 or 4 PM. This process of Westernization was initiated in the 1990s, and has led to higher job demands and changes in the work environment and the relationships between workers and their superiors.

Our study also emphasizes the death of a close friend or family member as a risk factor for MI occurrence and it seems that death of a close friend poses even higher risk for MI than death of a close family member. Death of a parent was the most reported death of a close family member among both cases and controls and represents a typical life course transition in the adult population in our study. The death of a close friend may be a more profound shock than the death of a close family member because it comes earlier than expected in the lifecycle and reminds subjects of their own mortality. Serbia had a major increase in premature mortality from neoplasms and diabetes mellitus compared to all European sub-regions.

The present study had several limitations, including the possibility that recall bias was present, which differed between cases and controls. Also, psychopathological response to the disease depends on personal characteristics and psychosocial environment.