Individual differences in circadian rhythm parameters and short-term tolerance to shiftwork: a follow-up study.
Vidacek S; Radosevic-Vidacek B; Kaliterna L; Prizmic Z
Ergonomics 1993 Jan; 36(1-3):117-123
The relationships between the amplitude, phase, and mesor of 24 hour rhythms obtained before exposure to shiftwork and various indices of tolerance measured after 1 and 3 years of shiftwork was investigated. The study was carried out on 204 young male subjects recruited from a training school to work at a large oil refinery. The mesor, amplitude, and acrophase of each individual's circadian rhythm were estimated by means of the COSINA computer program. Mesors of mood variables correlated significantly with some of the tolerance to shiftwork scores. All statistically significant correlations with the mesors of positive moods were positive, while those of negative moods and fatigue were negative. In general the results of the study showed either small or no relationships between the parameters of 24 hour rhythms obtained before workers entered shiftwork and their subsequent tolerance after a few years of shiftwork. This indicates that circadian rhythm parameters may be of limited importance in predicting short term tolerance to shiftwork.
NIOSH-Publication; NIOSH-Foreign-Research-Agreement; Circadian-rhythms; Shift-workers; Shift-work; Oil-refinery-workers; Psychological-factors; Worker-health; Physiological-effects