title: Shift work and endocrine disorders.
abstract: The objective of this review was to investigate the impact of shift and night work on metabolic processes and the role of alterations in the sleep-wake cycle and feeding times and environmental changes in the occurrence of metabolic disorders. The literature review was performed by searching three electronic databases for relevant studies published in the last 10 years. The methodological quality of each study was assessed, and best-evidence synthesis was applied to draw conclusions. The literature has shown changes in concentrations of melatonin, cortisol, ghrelin, and leptin among shift workers. Melatonin has been implicated for its role in the synthesis and action of insulin. The action of this hormone also regulates the expression of transporter glucose type 4 or triggers phosphorylation of the insulin receptor. Therefore, a reduction in melatonin can be associated with an increase in insulin resistance and a propensity for the development of diabetes. Moreover, shift work can negatively affect sleep and contribute to sedentarism, unhealthy eating habits, and stress. Recent studies on metabolic processes have increasingly revealed their complexity. Physiological changes induced in workers who invert their activity-rest cycle to fulfill work hours include disruptions in metabolic processes.
authors.affiliation: Department of Medicine, UNEC, Nossa Senhora das Graças, Unity II, 35300-345 Caratinga, MG, Brazil ; IMES, Rua João Patrício Araújo, No. 179 Veneza I, Ipatinga, MG, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Ulhôa
authors.affiliation: Department of Epidemiology, Graduate Program of Public Health, Catholic University of Santos, Avenida Conselheiro Nébias 300, Vila Matias, 11015-002 Santos, SP, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Marqueze
authors.affiliation: Department of Environmental Health, School of Public Health, University of São Paulo, Avenida Dr. Arnaldo 715, Cerqueira César, 01246-904 São Paulo, SP, Brazil.
authors.forename: L G A
authors.initials: LG
authors.lastname: Burgos
authors.affiliation: Department of Environmental Health, School of Public Health, University of São Paulo, Avenida Dr. Arnaldo 715, Cerqueira César, 01246-904 São Paulo, SP, Brazil ; Stress Research Institute, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: C R C
authors.initials: CR
authors.lastname: Moreno