When Does Stress End? Evidence of a Prolonged Stress Reaction in Shiftworking Truck Drivers

Abstract

This study aimed to analyze individual cortisol levels in relation to work conditions, sleep, and health parameters among truck drivers working day shifts (n = 21) compared to those working irregular shifts (n = 21). A total of 42 male truck drivers (39.8 ± 6.2 yrs) completed questionnaires about sociodemographics, job content, work environment, health, and lifestyle. Rest-activity profiles were measured using actigraphy, and cardiovascular blood parameters were collected. Salivary cortisol samples were obtained (i) at waking time, (ii) 30 min after waking, and (iii) at bedtime, during both one workday and one off day from work. Irregular shift workers showed significantly higher waist-hip ratio, VLDL-cholesterol, tiredness after work, years working as a driver, truck vibration, and less job demand compared to day workers (p < .05). High cortisol levels in irregular shiftworkers were correlated with certain stressors, such as short sleep duration and low job satisfaction, and to metabolic parameters, such as total cholesterol, HDL, LDL, VLDL, and triglycerides. Day workers had higher cortisol levels collected 30 min after waking (p = .03) and a higher cortisol awakening response (CAR, p = .02) during workdays compared to off days . Irregular shiftworkers had higher cortisol levels on their off days compared to day shiftworkers (p = .03). In conclusion, for the day workers, a higher cortisol response was observed on workdays compared to off days. Although no direct comparisons could be made between groups for work days, on off days the irregular shiftworkers had higher cortisol levels compared to day workers, suggesting a prolonged stress response in the irregular group.In addition, cortisol levels were correlated to stressors and metabolic parameters. Future studies are warranted to investigate further stress responses in the context of irregular work hours. (Author's correspondence: crmoreno@usp.br)

Nutritional, Metabolic and Cardiovascular Correlations of Morning Cortisol in Health Care Workers in a Gastroenterology Service

“…Cortisol peaks half an hout after waking, and the stronger the increase (CAR), the heavier the chronic perceived stress. For logistic reasons CAR could not be registered in this series, only the 30 minutes peak, however both are often related, and might be correlated with metabolic abnormalities (27) . Despite the lack of CAR estimates in the current protocol, the biochemical stress model was preferred for the purposes of objectivity and reproducibility, as psychological stress and burn out have been assessed by a heterogeneous array of questionnaires, scales, instruments and inventories (11,17,22,23,31) .…”

“…Only morning cortisol was registered, not circadian profile, or specific stimulation and suppression maneuvers (6,8,24,27) . Urinary, salivary or hair cortisol were not monitored, nor epinephrine, norepinephrine, cytokines or other biomolecules (6,10,19,26) .…”

Factors Associated With Shift Work Disorder in Nurses Working With Rapid-Rotation Schedules in Japan: The Nurses’ Sleep Health Project

“…Indeed, the prevalence of excessive sleepiness is known to be higher in shiftworkers than in non-shiftworkers (Drake et al, 2004;Garbarino et al, 2002;Pallesen et al, 2007). Moreover, it has been reported that their irregular working hours might increase their vulnerability to the development of insomnia symptoms (Drake et al, 2004;Garbarino et al, 2002;Lin et al, 2012), elevated stress response (Ulhoa et al, 2011), decreased mental health (Lin et al, 2012), and depressed mood (Driesen et al, 2010).…”

Stress and salivary cortisol in emergency medical dispatchers: A randomized shifts control trial

“…All these factors contribute to increased sick leave [14] and an increased turnover of phone operators owing to their premature departure to other less stressful professions [15]. Objective measurements of stress are therefore needed to develop evaluable preventive strategies of stress management [16,17,18]. To identify stress at a biological level, cortisol is the historical biomarker which can now be assessed easily and pain-free from saliva [19,20,21,22,23].…”