TY - JOUR

T1 - Neuroendocrine recovery after 2-week 12-h day and night shifts

T2 - an 11-day follow-up

AU - Merkus, Suzanne L

AU - Holte, Kari Anne

AU - Huysmans, Maaike A

AU - Hansen, Åse Marie

AU - van de Ven, Peter M

AU - van Mechelen, Willem

AU - van der Beek, Allard J

PY - 2015/2

Y1 - 2015/2

N2 - PURPOSE: The study aimed to investigate the course and duration of neuroendocrine recovery after 2-week 12-h day and night shift working periods and to study whether there were differences in recovery between the shift groups.METHODS: Twenty-nine male offshore employees working 2-week 12-h shift tours participated in the study; 15 participated after a day shift tour and 14 after a night shift tour. Salivary cortisol was assessed at awakening, 30 min after awakening, and before bedtime on the 1st, 4th, 7th, and 11th day of the free period, with a reference day prior to the offshore tour. Differences were tested using generalised estimating equations analysis.RESULTS: Compared to the reference day, night shift workers had a significantly flatter cortisol profile on the 1st day off, significantly lower cortisol concentrations at 30 min after awakening on day 4 and at awakening on day 7, and a significantly smaller decline to evening concentration on days 4 and 11. Compared to the reference day, day shift workers only showed a significantly lower cortisol concentration at awakening on the 1st day off. Compared to day workers, night shift workers had a flatter profile on the 1st day off and a lower cortisol concentration at awakening on the 4th day.CONCLUSIONS: Following 2-week 12-h night shift working periods, recovery was not fully complete up to day 11. Following 2-week 12-h day shift working periods, an indication of incomplete recovery was found on the 1st day off, with full recovery reached on day 4.

AB - PURPOSE: The study aimed to investigate the course and duration of neuroendocrine recovery after 2-week 12-h day and night shift working periods and to study whether there were differences in recovery between the shift groups.METHODS: Twenty-nine male offshore employees working 2-week 12-h shift tours participated in the study; 15 participated after a day shift tour and 14 after a night shift tour. Salivary cortisol was assessed at awakening, 30 min after awakening, and before bedtime on the 1st, 4th, 7th, and 11th day of the free period, with a reference day prior to the offshore tour. Differences were tested using generalised estimating equations analysis.RESULTS: Compared to the reference day, night shift workers had a significantly flatter cortisol profile on the 1st day off, significantly lower cortisol concentrations at 30 min after awakening on day 4 and at awakening on day 7, and a significantly smaller decline to evening concentration on days 4 and 11. Compared to the reference day, day shift workers only showed a significantly lower cortisol concentration at awakening on the 1st day off. Compared to day workers, night shift workers had a flatter profile on the 1st day off and a lower cortisol concentration at awakening on the 4th day.CONCLUSIONS: Following 2-week 12-h night shift working periods, recovery was not fully complete up to day 11. Following 2-week 12-h day shift working periods, an indication of incomplete recovery was found on the 1st day off, with full recovery reached on day 4.

U2 - 10.1007/s00420-014-0954-5

DO - 10.1007/s00420-014-0954-5

M3 - Journal article

C2 - 24974161

VL - 88

SP - 247

EP - 257

JO - International Archives of Occupational and Environmental Health

JF - International Archives of Occupational and Environmental Health

SN - 0340-0131

IS - 2

ER -