OBJECTIVES: We sought to measure melatonin levels and 24-hour light intensity exposure in health care workers over a 7-day period in natural occupational and residential settings. METHODS: Five office workers and 17 nurses working either days or rotating night and day shifts wore a device to record light intensity exposure for one or two 7-day periods, completed a questionnaire, and provided three saliva samples for melatonin. RESULTS: Rotating shift workers had irregular light exposure patterns and abnormal melatonin levels compared with those working days. In addition to lower-than-normal melatonin levels during sleep periods, rotating shift workers exhibited higher-than-normal melatonin levels on arising and during work. Self-reported years of shift work were correlated with measured melatonin and light. CONCLUSIONS: Rotating shift work is supported as a surrogate for exposure to light-at-night and circadian disruption.
OBJECTIVES: We sought to measure melatonin levels and 24-hour light intensity exposure in health care workers over a 7-day period in natural occupational and residential settings. METHODS: Five office workers and 17 nurses working either days or rotating night and day shifts wore a device to record light intensity exposure for one or two 7-day periods, completed a questionnaire, and provided three saliva samples for melatonin. RESULTS: Rotating shift workers had irregular light exposure patterns and abnormal melatonin levels compared with those working days. In addition to lower-than-normal melatonin levels during sleep periods, rotating shift workers exhibited higher-than-normal melatonin levels on arising and during work. Self-reported years of shift work were correlated with measured melatonin and light. CONCLUSIONS: Rotating shift work is supported as a surrogate for exposure to light-at-night and circadian disruption.
Authors: Marie Aarrebo Jensen; Anne Helene Garde; Jesper Kristiansen; Kirsten Nabe-Nielsen; Åse Marie Hansen Journal: Int Arch Occup Environ Health Date: 2015-10-13 Impact factor: 3.015
Authors: Danilo S Ferreira; Fernanda G Amaral; Caroline C Mesquita; Ana Paula L Barbosa; Camilo Lellis-Santos; Ariane O Turati; Laila R Santos; Carolina S Sollon; Patricia R Gomes; Juliana A Faria; José Cipolla-Neto; Silvana Bordin; Gabriel F Anhê Journal: PLoS One Date: 2012-06-12 Impact factor: 3.240