Chronobiology international
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Night-float rotations were designed to alleviate the workload of residents on night call and thereby improve patient safety. However, the impact of the night float on residents is yet to be surveyed. We assessed the impact of the night-float rotation on pediatric residents using an anonymous questionnaire that covered topics, based on recall, about sleep, mood, alertness, adjustment, and others. ⋯ The results suggest that disturbances of sleep and mood and decreased alertness, typical of night shift, are present in the night-float rotation. Residency programs should monitor closely the impact of the night-float rotation on resident well being and patient safety. The impact of night-shift work should be considered in the design of night-float schedules, and teaching should be provided for residents to learn coping strategies for night-shift work.
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A recent worldwide trend in chemical and petrochemical industries is to extend the duration of shifts. Optimization of the labor force to reduce costs is one reason to increase the length of working time in a shift. Implementation of 12h shifts is a controversial decision for managers and scientists. ⋯ The results of this study show poorer sleep after and significantly decreased alertness during night work. Shifts of 12h are usually implemented for technical and economic reasons. These results point out the necessity of a careful trade-off between the financial and technical gains longer shifts might bring and the possible losses due to incidents or accidents from performance decrements during work.
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Increased stress responsivity and a longer-lasting glucocorticoid increase are common findings in aging studies. Increased cortisol levels at the circadian nadir also accompany aging. We used 24 h free urine cortisol to assess these age changes in healthy seniors. We hypothesized that free cortisol levels would explain individual differences in age-related sleep impairments. ⋯ These results indicate that free cortisol (as indexed by 24 h urine values) can index responses to mild stress in healthy senior adults, revealing functional correlations (impaired sleep, earlier times of arising, more EEG beta activity during sleep, more IL-1beta) and gender differences.
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Bromocriptine, a dopamine D2 agonist, inhibits seasonal fattening and improves seasonal insulin resistance in Syrian hamsters. Alterations in daily rhythms of neuroendocrine activities are involved in the regulation of seasonal metabolic changes. Changes in circadian neuroendocrine activities that regulate metabolism are believed to be modulated by central circadian oscillators within the hypothalamic suprachiasmatic nuclei (SCN) of seasonal animals. ⋯ This was confirmed by a further in vivo microdialysis study in which bromocriptine increased SCN extracellular 5-HIAA of glucose-intolerant hamsters during the dark phase (47% increase, p < .05) toward levels observed in normal glucose-tolerant hamsters. Thus, bromocriptine-induced resetting of daily patterns of SCN neurotransmitter metabolism is associated with the effects of bromocriptine on attenuation of the obese insulin-resistant and glucose-intolerant condition. A large body of corroborating evidence suggests that such bromocriptine-induced changes in SCN monoamine metabolism may be functional in its effects on metabolism.
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Clinical Trial Controlled Clinical Trial
Effect of melatonin on sleep quality of COPD intensive care patients: a pilot study.
Sleep deprivation is extremely common in the intensive care unit (ICU), and this lack of sleep is associated with low melatonin secretion. The objective of the current study was to explore the effect of exogenous melatonin administration on sleep quality in patients hospitalized in the pulmonary intensive care unit (ICU). We performed a double-blind, placebo-controlled study in the pulmonary ICU of a tertiary care hospital. ⋯ Patients received either 3 mg of controlled-release melatonin or a placebo at 22:00, and sleep quality was evaluated by wrist actigraphy. Treatment with controlled-release melatonin dramatically improved both the duration and quality of sleep in this group of patients. Our results suggest that melatonin administration to patients in intensive care units may be indicated as a treatment for sleep induction and resynchronization of the "biologic clock." This treatment may also help in the prevention of the "ICU syndrome" and accelerate the healing process.