Changes in melatonin and sex steroid hormone production among men as a result of rotating night shift work - the HORMONIT study

• Published in: Scandinavian journal of work, environment & health Vol. 48; no. 1; pp. 41 - 51
• Main Authors: Harding, Barbara N, Castaño-Vinyals, Gemma, Palomar-Cros, Anna, Papantoniou, Kyriaki, Espinosa, Ana, Skene, Debra J, Middleton, Benita, Gomez-Gomez, Alex, Navarrete, José Maria, Such, Patricia, Torrejón, Antonio, Kogevinas, Manolis, Pozo, Oscar J
• Format: Journal Article
• Language: English
• Published: Finland Scandinavian Journal of Work, Environment & Health 01.01.2022; Nordic Association of Occupational Safety and Health; Nordic Association of Occupational Safety and Health (NOROSH)
• Subjects: Androgens; Cancer; circadian; Circadian Rhythm; Circadian rhythms; Confidence intervals; Enzymes; Estrogens; Gonadal Steroid Hormones; Health risks; hormone; hormone production; Hormones; hormonit; Humans; Light; Male; Melatonin; Melatonin - metabolism; Men; Metabolites; Night shifts; night work; Nighttime; Original; Population; rotating shift work; Sensors; Sex hormones; sex steroid; Shift work; Shift Work Schedule; shift worker; Steroid hormones; Steroids; Sulfatoxymelatonin; Testosterone; Urine; Work Schedule Tolerance; Workers; Spain
• ISSN: 0355-3140; 1795-990X; 1795-990X
• DOI: 10.5271/sjweh.3991

Data from real world settings on circadian disruption and subsequent hormone-related changes may explain the higher risk of hormone-dependent cancers among night shift workers.The present study examines the melatonin and sex steroid hormone levels among night shift workers. We included 44 male, rotating shift workers from a car factory in Spain, sampled both at the end of a 3-week night shift (22:00-06:00 hrs) and a 3-week early morning shift (06:00-14:00 hrs). Participants collected all urine voids over 24-hours during each shift. Urinary concentrations of sex steroid hormones (estrogens, androgens and progestogens) and 6-sulfatoxymelatonin (aMT6s, major melatonin metabolite) were determined. Individual cosinor analysis was used to derive the acrophase (peak time) and area under the curve (total production). Linear mixed models examined intraindividual associations between night shift work and log-transformed 24-hour peak time and total production of hormones compared to early morning shift work. The acrophase was delayed during the night shift for aMT6s [geometric mean difference (GMD) 7.53 hrs, 95% confidence interval (CI) 4.46-10.60], androgens (eg, testosterone: GMD 6.83 hrs, 95% CI 0.34-13.32) and progestogens (eg, 17-hydroxyprogesterone: GMD 4.54 hrs, 95% CI 2.92-6.16) compared to the early morning shift. We found a higher production of adrenal androgen 11-oxoandrosterone/11-oxoetiocholanolone [geometric mean ratio (GMR) 1.43, 95% CI 1.12-1.81], and a lower production of adrenal progestogen 16-cysteinylprogesterone (GMR 0.79, 95% CI 0.67-0.93) during the night shift compared to the early morning shift levels. Night shift work was associated with melatonin and sex hormone-related changes in timing and total production, providing insight into the mechanistic path for its association with hormone-dependent cancer.