Veille documentaire MTPH

Auteur     Beata Peplonska
Auteur     Agnieszka Bukowska
Auteur     Jolanta Gromadzinska
Auteur     Wojciech Sobala
Auteur     Edyta Reszka
Auteur     Jenny-Anne Lie
Auteur     Helge Kjuus
Auteur     Wojciech Wasowicz
Résumé     ObjectivesSynthesis of melatonin follows a circadian cycle, with high melatonin levels during the night and low levels during the day. Light exposure at night has been hypothesised as one of potential mechanisms of breast carcinogenesis in the night shift workers through inhibition of melatonin synthesis. The aim of the study was to examine a number of determinants for night shift work in relation to 6-sulfatoxymelatonin (MT6s), primary melatonin metabolite.MethodsThe cross-sectional study included 354 nurses and midwives (aged 40-60 years) currently working on rotating night shifts and 370 working days only. Data from questionnaires and 1-week diaries were used to characterise current job and total occupational history. Associations between rotating night shift work characteristics and MT6s (creatinine adjusted) in spot morning urine were tested in multiple linear regression models.ResultsNo significant differences were found for MT6s concentrations between women currently working on rotating night shifts and those working only day shifts (means 47.2 vs 45.7 ng/mg Cr, respectively). The adjusted means among rotating night shift nurses and midwives varied depending on the department of employment, from 35.1 ng/mg Cr in neonatology to 68.2 ng/mg Cr in the orthopaedics department. Women working eight or more night shifts per month had significantly lower MT6s levels than those having fewer night shifts per month (37.9 vs 47.4 ng/mg Cr, respectively). Total night shift work history was not associated with MT6s.ConclusionsThe results of this study indicate that working eight or more night shifts per month may disrupt the synthesis of melatonin.
Publication     Occupational and Environmental Medicine
Date     Feb 25, 2012