Skip Navigation LinksHome > July 2011 - Volume 53 - Issue 7 > Sleep Habits, Alertness, Cortisol Levels, and Cardiac Autono...
Journal of Occupational & Environmental Medicine:
doi: 10.1097/JOM.0b013e318221c6de
Original Articles

Sleep Habits, Alertness, Cortisol Levels, and Cardiac Autonomic Activity in Short-Distance Bus Drivers: Differences Between Morning and Afternoon Shifts

Diez, Joaquín J. MD; Vigo, Daniel E. MD, PhD; Pérez Lloret, Santiago MD, PhD; Rigters, Stephanie MD; Role, Noelia BSc; Cardinali, Daniel P. MD, PhD; Pérez Chada, Daniel MD

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Objective: To evaluate sleep, alertness, salivary cortisol levels, and autonomic activity in the afternoon and morning shifts of a sample of short-distance bus drivers.

Methods: A sample of 47 bus drivers was evaluated. Data regarding subjects and working characteristics, alertness (psychomotor vigilance task), sleep habits (Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Actigraphy), endocrine stress response (salivary cortisol), and autonomic activity (heart-rate variability) were collected.

Results: Sleep restriction was highly prevalent. Drivers in the morning shift slept 1 hour less than those in the afternoon shift, showed lower reaction time performance, a flattening of cortisol morning-evening difference, and higher overweight prevalence.

Conclusions: The differences found between morning and afternoon shifts point out to the need of the implementation of educational strategies to compensate the sleep loss associated with an early workschedule.

©2011The American College of Occupational and Environmental Medicine


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