Stress is a nonspecific reaction caused by stressful factors and conditions in an individual and endangers one's physical and mental health(1).Although there are many different definitions of stress, the scientific definition of stress from the perspective of the proposed model of Richard Lazarus can be expressed as follows: Stress is a condition or feeling in which one perceives that the sum of his desires and expectations are beyond his resources, capabilities and abilities. Also, Lazarus and Folkman (1984) defined stress as a specific relationship between a person and his environment. In fact, it is a stressful relationship between the person and his environment that he suffers from mental and physical problems due to inability to cope with this situation(2). Job stress in the nursing profession increases absenteeism, decreases performance and increases early resignation from work (3). On the other hand, when the balance between free radical production and antioxidants is disturbed, oxidative stress occurs, which leads to cell damage or death, subsequent damage and eventually chronic disease(4).
Hospitals and health centers are like an industrial unit consisting of capital, manpower, technology and management that nurses are among the manpower of these centers and do 80% of the work of medical centers and hospitals (5). Despite the large number of hospitals and various specialties in the medical staff, nurses are at the forefront of providing healthcare services, which in turn complicates and expands their tasks (6). Stress is a word derived from the Latin ‘stringere’, which in the 17th century was used to mean pain and suffering, and the word means pressure – strain or force (7). Stress is an unavoidable part of human life, and today, it includes external stimuli and an individual's response to it and affects all people. Although sometimes it is natural and necessary, if stress is persistent, repetitive and severe, or the person is not able to cope with it or has few sources of support, it becomes a negative phenomenon that causes physical and mental illnesses (7, 8). Job stress can be defined as the interaction between a person’s characteristics and his job in such a way that the job pressure is more than the ability of the person to cope with the job (5).
A nurse can be defined as a person who controls and monitors patients all the working hours and is exposed to the stress of performing these tasks (9, 10). Studies have shown that nurses are considered the largest human resource and medical staff (11). The National Institute of Safety and Health (NIOSH) ranked nursing among the top 40 professions with high stress and stress-related disorders among staff. It is believed that in the case of job stress, nursing may be included in the list of health care (5). After mining, nursing is known as the hardest job in the world and the nursing profession is defined as a job with high stress (12–15).
Several studies address various aspects of the stress that an individual faces in his life, including the following: 1) Stress related to living environment (home), 2) Stress in personal life, and 3) Stress related to workplace (16, 17). One of the most important sources of stress is a person’s job characteristics and job stress has become a common and costly issue in the workplace [18]. Studies have identified job stress as a 20th-century disease and a pervasive issue [19]. Edward and Bernard (2003) have introduced workplace stress as the same as job stress [20]. After disorders, job stress is the second most common work-related problem and absenteeism due to stress costs billions of pounds a year [21].
Many studies have examined the stressors in nurses. In a study by Tyson and his colleagues (2004), workload, dealing with life and death situations and performing tasks beyond capacity and ability [22], and in a study by Ramel and colleagues (2006), high workload, inadequate counseling and communication, inadequate performance feedback, inadequate resources for coping with stress and work-family conflict, were mentioned as major sources of nurses’ stress [23].
Job stress leads to excessive formation of free radicals, reactive oxygen species [24]. Reactive Oxygen Species (ROS) can cause diseases such as diabetes, atherosclerosis, cancer and Parkinson’s disease [25]. Free radicals in the human body are formed in the cytosol, mitochondria, lysosomes, proxysomes and plasma membranes under both physiological and pathological conditions. They begin as a cascade and cause peroxidation of fat cells that directly damage the biological membrane, producing a number of by-products such as aldehydes and malondialdehyde (MDA), of which aldehydes are the most abundant due to the fat oxidation [26]. The human body has an integrated antioxidant system which includes enzymatic and non-enzymatic antioxidants that are usually effective in preventing the harmful effects of free radicals. Normally, antioxidants convert ROS to H2O, which prevents the increase of reactive oxygen species. Enzymatic antioxidants, including superoxide dismutase (SOD), glutathione peroxide (GPX), and catalase (CAT), are responsible for intracellular protection [27]. Tsuboi and his colleagues (2006) indicated that the association between high levels of MDA and burnout symptoms in participants was low and there was a significant positive difference between the levels of MDA/TC ratio in low stress [28].
Salem and her colleagues conducted a study entitled “Psychosocial Work Environment and oxidative stress among Nurses” in 2016. The results of his study showed that MDA was significantly positively correlated with E/R and work stress, which was common among nurses, showed a high correlation between ERI and MDA levels and the highest stress was reported in hospital wards, ICUs, and operating rooms [29].
Adriano Silva Silveira and his colleagues conducted a study entitled “Oxidative stress effects in the uterus, placenta and fetus of pregnant rats submitted to acute and chronic stress” in 2018.The results suggested that there was no meaningful difference in MDA levels, but there was a correlation between infant size, placental weight and MDA levels. In this study, stress had negative effects on the group exposed to chronic stress compared to the control group, the rats exposed to chronic stress had fewer placentas, embryos and infants compared to the other groups and abortion rates were also higher in this group [30].
A cross-sectional study entitled “Relation between Job stress and Oxidative stress Biomarkers among Nurses in Zagazig University Hospitals” was conducted by Amira Shawally Mohamed and her colleagues in 2019. The results showed that the rate of severe stress in nurses was 65% and in administrative staff was 7.5% and the levels of MDA and SOD in nurses were significantly higher than the administrative or control group [31].
Based on what mentioned above, the present study aims to determine the effect of job stress on oxidative stress in nurses of a hospital in western Iran.