Year: 2013
Type: dissertation
Study design: Observational Study
Abstract: Good recovery helps to restore functional reserves and facilitates the positive effects of stress at work. The risk of job stress is increased by excessive quantitative demands, low job control, poor recovery and disruption of biological rhythms. Stress causes changes in autonomic nervous system (ANS) function and in excretion of cortisol hormone regulated by hypothalamus-pituitary-adrenal cortex (HPA) axis. Melatonin and cortisol are diurnally oscillating hormones reflecting disruption of biological rhythms. Common symptoms of harmful stress are sleep problems, exhaustion and decrease in work efficiency. The risk of many common diseases increases. In this study perceived and physiologically measured stress and recovery were analysed in media work, which contains typical risk factors of job stress in 24/7 society. A standardized questionnaire was mailed to all employees of the Finnish Broadcasting Company with irregular shift work (ISW, n = 750) and to an equal number of randomly selected controls with regular 8-hour daytime work (RDW). The questionnaire included items of work characteristics, perceived stress, mental and physical health and lifestyle. The response rate was over 80 % in ISW group and about 35 % in RDW group. Seventy respondents from both groups were randomly selected for physiological measurements. Cortisol and melatonin hormones were analysed from five salivary samples taken while subjects were awake. Heart rate variability as indicator of ANS function was calculated from 24 hour ECG recordings. Body movements were monitored by actigraphy. Severe subjective stress, irregular shift work, and short actual sleep time were all significant explanatory variables of augmented morning cortisol response. The risk of daytime sleepiness was nearly twofold in the ISW group compared to the RDW group. The daytime sleepiness was associated with attenuated relaxation of ANS during sleep in ISW group. The changes in the afternoon and evening levels of cortisol and melatonin hormones might predispose to difficulties in initiating sleep. In all, about 40 % of workers reported high job control and 40% low job control. During the recovery period (from 18.00 to 06.00 hrs between working days), those who experienced high job control at work had significantly better recovery of ANS function than other workers. Depression, hypertension and poor general health were associated with many types of sleep disorders and they all increased the risk of nocturnal waking. Severe stress doubled the risk of difficulties initiating sleep and the risk of non-restorative sleep. Analysis of recovery should be included in the evaluation of workers health and well-being in 24/7 society. Simultaneously analysed autonomic nervous system function and neuroendocrine indicators provide additional information about stress and recovery. Ambulatory measurements in real life settings could offer new insights in occupational health studies, once their validation has been achieved.
Source: Työväentutkimus Vuosikirja
Author: Harri Lindholm
Language: English
Subfield: Experimental and Cognitive Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
Funder: Työsuojelurahasto
OpenAlex ID: W1579019017