Original scientific paper
Shift work and psychophysiological
Andrea Tokić -
Department of Psychology, University of Zadar, Obala kralja Petra Krešimira IV 2, 23000 Zadar
Fulltext (english, pages 21-30).pdf
Shift work is considered a risk factor for health problems due to the continuous desynchronization
and resynchronization of circadian rhythms. This study used heart rate measurement during sleep to
determine whether shift work, and different length of this work, affects nonlinear aspects of cardiovascular
dynamics, indicators of the autonomous nervous system, in healthy shift workers. The study included 48
healthy, premenopausal, female participants (nurses) divided in two groups of equal age and length of service.
One group worked in a three-shift rotation system and the other (control) worked only the day shift.
Cardiac activity (R-R intervals) was monitored continuously during sleep using the Data Logging System.
Cardiac activity was recorded in both day and shift workers at night after the second consecutive day shift.
Results showed that shift workers with up to 10 years of service had higher values of correlation dimension
than the equivalent group of day workers but shift workers with more than 10 years of service had lower values
of correlation dimension than comparable groups of day workers. All shift workers, regardless of length
of service, had significantly higher indices of determinism than day workers, but the index of determinism
slightly enlarges with increased years of services. Generally, it seems that shift work has a negative impact
on cardiovascular dynamics from the very beginning, and nonlinear parameters of cardiovascular dynamics
can be potential predictors of future health problems.
shift work, cardiovascular dynamics, R-R interval, index of determinism, correlation dimension