Two studies recently published in the Journal showed that disruption of diurnal sleep–wakefulness rhythms, especially through nighttime shift work, was associated with higher subsequent breast cancer incidence (1,2). Both of the articles and the accompanying editorial cited melatonin suppression as a likely mediator via reduced suppression of ovarian estrogen production due to light exposure du...

OBJECTIVES Synthesis 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 rela...

Two studies recently published in the Journal showed that disruption of diurnal sleep–wakefulness rhythms, especially through nighttime shift work, was associated with higher subsequent breast cancer incidence (1,2). Both of the articles and the accompanying editorial cited melatonin suppression as a likely mediator via reduced suppression of ovarian estrogen production due to light exposure du...

BACKGROUND Night shift work is associated with cancer among men, but the biologic mechanism is unclear. We investigated whether male night shift workers showed changes in levels of melatonin and cortisol, potential biomarkers of cancer risk. METHODS Urine was collected from 185 night shift and 158 day shift-working male healthcare providers, aged 22 to 55 years, throughout work and sleep peri...

BACKGROUND It has been proposed that night shift work could increase breast cancer incidence. A 2007 World Health Organization review concluded, mainly from animal evidence, that shift work involving circadian disruption is probably carcinogenic to humans. We therefore aimed to generate prospective epidemiological evidence on night shift work and breast cancer incidence. METHODS Overall, 522 ...

Anxiety is a feeling of worry and excessive concern against obscure danger about inner or outer threat, which occur in form of ambiguous fear. It finally causes physical problem and impairs social and occupational functions. Anxiety is the most common mental disorder. Nursing totally is a difficult job and because of their working environmental and activity, they always encountering with damage...

Background & Objective: Sleepiness and the trend of changes of vital signs are important factors affecting the quality of work of hospital staff. The purpose of this study was to investigate the relationship between sleepiness with physiological changes and vital signs in night shift workers in rehabilitation staff. Methods: This study was a cross-sectional study, performed on night shift pers...