Introduction: Sleep deprivation is a consequence of shift work and may have a negative impact on
the cognitive function of individuals. Other essential mental variables in information
processing, such as memory, accuracy, attention, and reaction time are also altered
by sleep deprivation. Previous studies suggested that sleep deprivation has adverse
effects on executive functions, attentional processes, as well as temporal and working
memory. According to Ansiau et al., cognitive and mental performance impairment can
cause serious issues in the workplace, particularly when an immediate and accurate
response is required Shift work may lead to sleep deprivation and perturb the circadian
system. Several other important cognitive performance indicators in information processing,
such as working memory, accuracy, attention, and reaction time, are significantly
altered by sleep deprivation as well. Since it is hypothesized that disruption of
the circadian rhythm is linked with an elevated risk of type 2 diabetes, the purpose
of this study was to examine the cognitive ergonomic performance of diabetic (type
2) and non-diabetic shift control operators.
Methods: Cognitive tests Reaction time test Stroop test Flickr Fusion test in this descriptive-analytical
cross- sectional study, 80 shift workers were recruited as the participants and divided
into two groups: diabetic (n = 40) and non-diabetic (n = 40). Using the Stroop Test, the Simple Reaction Time Test, and Flickr Fusion test,
cognitive function was assessed at the beginning, middle, and end of the work shift.
Data were analyzed in SPSS software (version 20) using an independent t-test. A p-value less than 0.05 was considered statistically significant.
Results: Data were analyzed in SPSS software (version 20). Frequency and percentage were utilized
for expressing the categorical variables. Kolmogorov-Smirnov test was used to evaluate
the normality of data distribution. An independent t- test was used for the comparison
of cognitive performance parameters between the two groups. In all calculations, a
p-value less than 0.05 was considered statistically significant. There was a significant
difference between the two groups regarding the Stroop test time at the beginning
(p = 0.015), middle (p = 0.022) and end of shift work (p = 0.024). A significant difference was observed with regard to the number of errors
between the two groups at the end of the shift work (p = 0.045). In all three stages, there were no significant differences between the
two groups in terms of mental fatigue and reaction time (P>0.05).
Conclusion: The results from this study indicated that diabetic and non-diabetic subjects differ
significantly in several cognitive abilities. In comparison to non-diabetic participants,
cognitive skills were severely diminished among the diabetic ones. Cognitive impairments
were also influenced by the time (beginning, middle, and end) of shift work, with
the lowest cognitive function observed at the end of the shift. Support (if any):
Conclusion As evidenced by the results of this study, it can be concluded that diabetic
and non-diabetic subjects significantly differed in most cognitive performances. Cognitive
functions were significantly poorer in diabetic participants, as compared with those
in non-diabetic subjects. The time (beginning, middle, and end) during shiftwork was
also an important factor for cognitive impairments, with the lowest cognitive performance
being observed at the end of the shift. According to the obtained results, more effective
preventive measures are necessary to reduce human errors caused by insufficient sleep,
especially in people with underlying diseases, such as diabetes, in shift work. Funding:
This research was funded by the Isfahan University of Medical Sciences, Isfahan, Iran
(Grant number 398734 and ethical number IR.MUI.RESEARCH.REC.1398.665).
