دانلود رایگان مقاله انگلیسی واکنشهای فیزیولوژیکی به ماهیگیری طولانی مدت در دریای بارنتز - 2018 Oxford

Background Fishing in distant waters for months may induce physiological stress. Aims To assess the physiological stress reactions in fishermen working for 2–3 months continuously in 6-h shifts on trawlers in the Barents Sea. Methods The crew of five trawlers fishing in the Barents Sea from January to April 2004 were invited to participate. In the week before and 5–7 days after the trip, the following measures were collected: salivary cortisol four times a day, 24-h urinary cortisol, blood pressure, heart rate, serum cholesterol, serum high-density lipoprotein (HDL-cholesterol), HbA1c (glycosylated haemoglobin) and weight. In addition, 24-h urinary cortisol, blood pressure and heart rate were measured three times. A questionnaire on health, social conditions and work environment was obtained after the trip. Results In total, 136 men agreed to participate. Full data were obtained for 96 fishermen (70%). A significant decrease in salivary and urinary cortisol was found during the trip. Adjustment for age, body mass index, smoking, shift work schedule and time of day for sample collection did not change this finding. Systolic and diastolic blood pressure declined significantly and remained significantly lower after the trip compared to before the trip. Serum cholesterol/HDL ratio declined significantly, whereas triglycerides, HbA1c and weight were unchanged. Conclusions Working up to 3 months on 6-h shifts, 84 h a week, with moderate physical activity, even in artificial light and cold weather on a ship, did not result in increased physiological stress. Key words Blood pressure; cortisol; fishing; shift work.

Discussion

Cortisol excretion measured in saliva showed a flattened diurnal curve, which developed into a normal curve with a peak in the morning during the trip. No difference was found between the two work time schedules. The total cortisol excretion decreased during the trip, a result that was supported by the measurements of urinary cortisol. This was most pronounced among those with normal working hours. In addition, the coronary risk profile assessed by measurement of blood pressure and lipids improved. In this context, it should be noted that the blood sugar level and weight among the participants remained the same. This might seem surprising because the working conditions might lead to both physical and psychological stress, which might affect at least the blood pressure level. As stated by Høye et al. [6], the urinary catecholamine excretion and heart rate in fishermen during long-line bank fishing were not as high as in coastal fishermen. It is noticeable that the cortisol levels found in this study were inside the 95% confidence intervals for both saliva cortisol (1.1–35.7 nmol/l) [21] and urinary cortisol (1.1–10.5 nmol/l) [24]. The interpretation of this could be that working without diurnal variation of sunlight in fixed-schedule and normally well-arranged work with predictable tasks was much less stressful than we expected. All the results from this study suggest that working for 2–3 months on 6-h shifts with no regular personal contact with family and other non-work-related relations, with moderate physical activity even in artificial light and cold weather on a ship, did not increase the physiological stress reaction. Rather the opposite was the case. Regular intake of healthy food, which is the recommendations on the ships, and no alcohol intake might contribute to this too.