Τίτλος:
Circadian Variation of Melatonin, Light Exposure, and Diurnal Preference
in Day and Night Shift Workers of Both Sexes
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Background: Light-at-night has been shown in experimental studies to
disrupt melatonin production but this has only partly been confirmed in
studies of night shift workers. In this cross-sectional study, we
examined the circadian variation of melatonin in relation to shift
status, individual levels of light-at-night exposure, and diurnal
preference, an attribute reflecting personal preference for activity in
the morning or evening.
Methods: One hundred and seventeen workers (75 night and 42 day) of both
sexes, ages 22 to 64 years, were recruited from four companies.
Participants collected urine samples from all voids over 24 hours and
wore a data logger continuously recording their light exposure.
Sociodemographic, occupational, lifestyle, and diurnal preference
information were collected by interview. Concentrations of urinary
6-sulfatoxymelatonin (aMT6s), the main melatonin metabolite, were
measured.
Results: Mean aMT6s levels were lower in night [10.9 ng/mg
creatinine/hour; 95% confidence interval (CI), 9.5-12.6] compared with
day workers (15.4; 95% CI, 12.3-19.3). The lowest aMT6s levels were
observed in night workers with morning preference (6.4; 95% CI,
3.0-13.6). Peak time of aMT6s production occurred 3 hours later in night
(08:42 hour, 95% CI, 07:48-09:42) compared with day workers (05:36
hour, 95% CI, 05:06-06:12). Phase delay was stronger among subjects
with higher light-at-night exposure and number of nights worked.
Conclusions: Night shift workers had lower levels and a delay in peak
time of aMT6s production over a 24-hour period. Differences were
modified by diurnal preference and intensity of light-at-night exposure.
Impact: Night shift work affects levels and timing of melatonin
production and both parameters may relate to future cancer risk. (C)
2014 AACR.
Συγγραφείς:
Papantoniou, Kyriaki
Pozo, Oscar J.
Espinosa, Ana
Marcos,
Josep
Castano-Vinyals, Gemma
Basagana, Xavier
Ribas, Ferran
Calduch
Mirabent, Joan
Martin, Jordi
Carenys, Gemma and
Martin, Celia Reyes
Middleton, Benita
Skene, Debra J. and
Kogevinas, Manolis
Περιοδικό:
Cancer Epidemiology, Biomarkers & Prevention
Εκδότης:
AMER ASSOC CANCER RESEARCH
DOI:
10.1158/1055-9965.EPI-13-1271
