Attenuation of vagal recovery during sleep and reduction of cortisol/melatonin ratio in late afternoon associate with prolonged daytime sleepiness among media workers with irregular shift work.
Media work is characterized by information flow, deadlines, and 24/7 alertness. Good recovery prevents stress-related disorders.
The standardized questionnaire included items about health, health habits, sleep, work conditions, and work stress. Recordings of 24-hr heart rate variability (HRV) and four salivary samples for cortisol and melatonin levels were analyzed from 70 randomly selected workers with irregular shift work, and 70 workers with normal daytime work.
Irregular shift work increased the risk of insufficient recovery when compared to normal daytime work (OR 2.0; P