Affiliations: Centre for Chronobiology, Faculty of Health and
Medical Sciences, University of Surrey, Guildford, UK | CBMT, Charleroi, Belgium | ArcelorMittal Industeel Belgium, Charleroi,
Belgium | Sleep Laboratory, CHU de Charleroi, Université
Libre de Bruxelles, Brussels, Belgium | Department of Sports Medicine, Institute of Exercise
and Health Sciences, University of Basel, Basel, Switzerland
Note: [] Corresponding author: Dr. Thomas Kantermann, University of
Groningen, Chronobiology – Centre for Behaviour and Neurosciences,
Nijenborgh 7, 9747 AG Groningen, The Netherlands. Tel.: +31 50 363 7117;
E-mail: thomas@kantermann.de
Abstract: OBJECTIVE: The aim of this study was to identify atherosclerotic
risk using pulse wave velocity (PWV) in steel workers employed in different
shift-work rotations, and to elucidate its relationship to social jetlag and
shift schedule details. PARTICIPANTS: Male workers in a steel factory (n=77, 32 fast
clockwise (CW), 30 slow counterclockwise (CC), 15 day workers (DW); mean age 42
± SD 7.6 yrs) with at least 5 years of experience in their current work
schedule participated. METHODS: All workers completed questionnaires on demographics,
health, psychotropic agents, sleep, social and work life, social jetlag
(difference between mid-sleep time on workdays and days off used as a marker of
circadian disruption) and chronotype (mid-sleep time on free days corrected for
sleep deficit on workdays). In 63 workers we measured PWV, blood pressure (BP),
heart rate (HR) between 08:00 and 12:30 h in controlled posture conditions (no
caffeine/smoking/exercise). RESULTS: There was no significant difference in PWV (covariates:
age, BP) between the different shift-rotations (CW, CC and DW). In all workers
combined, HR and social jetlag were significantly positively correlated.
Demographic variables did not differ between shift-workers and day workers;
shift-workers (CW, CC) reported significantly more stomach upsets, digestion
problems, weight fluctuations, and social jetlag. The CW and CC workers did not
differ in ratings of how shift-work affected sleep, social and work life. CONCLUSIONS: PWV was not different between the two shift-rotations.
This pilot study shows first evidence that HR is related to social jetlag, and
therefore warrants more studies in different shift schedules.
