title: Association between exposure to rotating night shift versus day shift using levels of 6-sulfatoxymelatonin and cortisol and other sex hormones in women.
abstract: The present study aims to compare 6-sulfatoxymelatonin (aMT6s) secretion patterns and levels of cortisol and sex hormones (estradiol, progesterone, DHEA, DHEAS, and testosterone) among rotating night-shift workers and day-shift workers. We performed a cross-sectional study in Cantabria (northern Spain) including 136 women (73 day-shift workers and 63 rotating night-shift workers). Blood and urine samples were obtained after two consecutive working days. Differences in means were estimated using ANCOVA, stratified by menopausal status, ovulation phase, and adjusted for season, age, body mass index, consumption of cigarettes in the last 24 h. aMT6s circadian rhythm was analyzed using the cosinor analysis. The present study showed that rotating night-shift workers had lower excretion of aMT6s than day-shift workers (mesor = 50.26 ng aMT6s/mg creatinine in women with rotating night shift versus 88.79 ng aMT6s/mg creatinine in women with day shift), lower fluctuation (amplitude = 45.24 ng aMT6s/mg creatinine in rotating night-shift workers versus 79.71 ng aMT6s/mg creatinine in day-shift workers), and a later acrophase (aMT6s peak time: 08:31 in rotating night-shift workers versus 07:13 h in day-shift workers). Additionally, women with rotating night shift had higher estradiol and progesterone levels, compared to day workers, especially in the follicular phase on the menstrual cycle.
authors.affiliation: Facultad de Medicina, Department of Preventive Medicine and Public Health, University of Cantabria , Santander , Spain .
authors.forename: Inés
authors.initials: I
authors.lastname: Gómez-Acebo
authors.forename: Trinidad
authors.initials: T
authors.lastname: Dierssen-Sotos
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Papantoniou
authors.forename: María Teresa
authors.initials: MT
authors.lastname: García-Unzueta
authors.forename: María Francisca
authors.initials: MF
authors.lastname: Santos-Benito
authors.forename: Javier
authors.initials: J
authors.lastname: Llorca
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood / Q000652:urine; D021081:Chronobiology Disorders / Q000097:blood* / Q000503:physiopathology / Q000652:urine*; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007587:Job Description; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D008875:Middle Aged; D010561:Personnel Staffing and Scheduling; D013030:Spain; D013997:Time Factors; D016526:Workload; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012739:Gonadal Steroid Hormones; C054513:6-sulfatoxymelatonin; D008550:Melatonin; D006854:Hydrocortisone
keywords: Breast cancer risk; circadian disruption; day-shift work; light exposure; rotating night shift work