The association between anxiety, hunger, the enjoyment of eating foods and the satiety after food intake in individuals working a night shift compared with after taking a nocturnal sleep: A prospective and observational study.

Subjective responses to meals are altered by shortened sleep time and anxiety state, but this effect has been poorly studied in shift workers - who act as a typical model concerning sleep restriction and present high levels of anxiety. The objective of this study was to compare subjective perceptions of meals and the levels of anxiety in the same subjects after working night shifts and after taking a nocturnal sleep, and to investigate associations between the responses to meals and the levels of anxiety under these two conditions. The study evaluated 34 male permanent night-shift workers who worked a 12-h shift followed by a 36-h rest period.

Association between chronotype, food intake and physical activity in medical residents.

An individual's chronotype is a trait which reflects his/her diurnal preferences for the times of rest and activities, and displays a continuum from morningness to eveningness. Studies have shown that eveningness tends to be associated with a less healthy lifestyle, including increased likelihood of developing obesity. In this study, we examined the relationship between chronotype and food intake, physical sleep and activity in 72 resident physicians (52 women and 20 men).

Chronotype, social jetlag and sleep debt are associated with dietary intake among Brazilian undergraduate students.

Undergraduate students experience a form of circadian misalignment - known as "social jetlag" - that represents the discrepancy in timing between their circadian and social clocks. Whilst social jetlag is not dependent upon chronotype, the two phenomena tend to be related; evening types show a tendency to have a greater social jetlag, for example. Moreover, evening types have been found to be more likely to have inadequate eating habits than do morning types.

Sleep pattern is associated with adipokine levels and nutritional markers in resident physicians.

Shift work and long hours of work are common in medical training and have been associated with a higher propensity for developing nutritional problems and obesity. Changes in leptin and ghrelin concentrations - two hormones that contribute importantly to the central regulation of food intake - are poorly described in this population. The aim of this study was to identify possible negative associations between sleep patterns, nutritional status and serum levels of adipokines.

Nutritional status and eating habits of bus drivers during the day and night.

The aim of this study was to compare anthropometry and food intake patterns in bus drivers working during the day and night. One hundred and fifty males (81 night workers and 69 day workers) participated in the study. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire.

Wrist actimetry circadian rhythm as a robust predictor of colorectal cancer patients survival.

The disruption of the circadian timing system (CTS), which rhythmically controls cellular metabolism and proliferation, accelerated experimental cancer progression. A measure of CTS function in cancer patients could thus provide novel prediction information for outcomes, and help to identify novel specific therapies. The rest-activity circadian rhythm is a reliable and non-invasive CTS biomarker, which was monitored using a wrist watch accelerometer for 2 days in 436 patients with metastatic colorectal cancer.

Daily rhythms of the sleep-wake cycle.

The amount and timing of sleep and sleep architecture (sleep stages) are determined by several factors, important among which are the environment, circadian rhythms and time awake. Separating the roles played by these factors requires specific protocols, including the constant routine and altered sleep-wake schedules. Results from such protocols have led to the discovery of the factors that determine the amounts and distribution of slow wave and rapid eye movement sleep as well as to the development of models to determine the amount and timing of sleep.

Adipokine levels are altered by shiftwork: a preliminary study.

Shiftwork is often associated with metabolic diseases, and in the past few years, several cytokines have been postulated to contribute to various diseases, including insulin resistance. The aim of this study was to compare the concentrations of adiponectin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in samples of young adult men exposed to a fixed (i) night shift (n = 9), working from 22:00 to 06:00 h; (ii) early morning shift (n = 6), working from 06:00 to 14:00 h; and (iii) day shift (n = 7), working from 08:00 to 17:00 h. The fixed night-shift and early-morning-shift samples were considered collectively as a shiftworker group given their work times.

Prediction of overall survival through circadian rest-activity monitoring during chemotherapy for metastatic colorectal cancer.

The clinical relevance of circadian rhythm modifications in patients on chemotherapy is unknown. Even so, circadian parameter I View Article and Find Full Text PDF

Hormonal appetite control is altered by shift work: a preliminary study.

Shift work has been associated with a higher propensity for developing nutritional problems and obesity. However, the possible changes in leptin and ghrelin (2 hormones that contribute importantly to the central regulation of food intake) concentrations in this population are poorly described. The objective of the study was to evaluate the daily concentrations of leptin, nonacylated ghrelin, and acylated ghrelin and the appetite ratings in men working different shift schedules.

The circadian body temperature rhythm of Djungarian Hamsters (Phodopus sungorus) revealing different circadian phenotypes.

Djungarian hamsters (Phodopus sungorus) of our breeding stock show three rhythmic phenotypes: wild type (WT) animals which start their activity shortly after "lights-off" and are active until "lights-on"; delayed activity onset (DAO) hamsters whose activity onset is delayed after "lights-off" but activity offset coincides with "lights-on"; and arrhythmic hamsters (AR) that are episodically active throughout the 24-h day. The main aim of the present study was to investigate whether the observed phenotypic differences are caused by an altered output from the suprachiasmatic nuclei (SCN). As a marker of the circadian clock, the body temperature rhythm purified from masking effects due to motor activity was used.

Respiratory rhythms in stingless bee workers: circadian and ultradian components throughout adult development.

The workers of the stingless bee, Melipona quadrifasciata, assume different tasks during their adult life. Newly emerged individuals remain inside the nest, without contact with the external environment. Maturing workers go to more peripheral regions and only the oldest, the foragers, leave the nest.

Circadian rhythms and cognition.

Like all circadian (near-24-h) rhythms, those of cognition have endogenous and exogenous components. The origins of these components, together with effects of time awake upon cognitive performance, are described in subjects living conventionally (sleeping at night and active during the daytime). Based on these considerations, predictions can be made about changes that might be expected in the days after a time-zone transition and during night work.

Effects of Ramadan on physical performance: chronobiological considerations.

This article focuses on changes in Ramadan during the course of the waking day in physical performance, mental performance and gastrointestinal function. Possible explanations of the changes are considered by reference to the roles of the body clock and external factors such as the environment and the individual's lifestyle. The effects of these factors upon training schedules and upon changing the times of training are then discussed in terms of physiology and biochemistry.

Circadian disruption, fatigue, and anorexia clustering in advanced cancer patients: implications for innovative therapeutic approaches.

A disruption of the circadian timing system, as identified by monitoring of marker biorhythms, is common in cancer patients. The recording of the rest-activity rhythm with a wrist actigraph has been commonly used. This noninvasive monitoring allows a robust estimation of circadian disruption.

Circadian rhythm in rest and activity: a biological correlate of quality of life and a predictor of survival in patients with metastatic colorectal cancer.

The rest-activity circadian rhythm (CircAct) reflects the function of the circadian timing system. In a prior single-institution study, the extent of CircAct perturbation independently predicted for survival and tumor response in 192 patients receiving chemotherapy for metastatic colorectal cancer. Moreover, the main CircAct parameters correlated with several health-related quality of life (HRQoL) scales.

Effects of one night of partial sleep deprivation upon diurnal rhythms of accuracy and consistency in throwing darts.

Sixty subjects were tested five times per waking day on two occasions for accuracy and reliability in throwing 20 darts at a target. Two experimental conditions were investigated: following a normal nocturnal sleep (7-8 h sleep, normal) and after having retired to bed 4 h later than normal the previous night but rising at the normal time (3-4 h sleep, sleep deprivation). Sublingual (core) temperature and subjective estimates of alertness and fatigue were measured in all sessions.

Sports performance: is there evidence that the body clock plays a role?

Athletic performance shows a time-of-day effect, possible causes for which are environmental factors (which can be removed in laboratory studies), the sleep-wake cycle and the internal "body clock". The evidence currently available does not enable the roles of these last two factors to be separated. Even so, results indicate that the body clock probably does play some role in generating rhythms in sports performance, and that to deny this is unduly critical.

Some chronobiological and physiological problems associated with long-distance journeys.

Long-distance travel is becoming increasingly common. Whatever the means of transport, any long journey will be associated with "travel fatigue". The symptoms associated with this phenomenon result from a changed routine (particularly sleep lost and meals) and the general disruption caused by travel.

The influence of sleep and sleep loss upon food intake and metabolism.

The present review investigates the role of sleep and its alteration in triggering metabolic disorders. The reduction of the amount of time sleeping has become an endemic condition in modern society and the current literature has found important associations between sleep loss and alterations in nutritional and metabolic aspects. Studies suggest that individuals who sleep less have a higher probability of becoming obese.

Effects of Ramadan upon fluid and food intake, fatigue, and physical, mental, and social activities: a comparison between the UK and Libya.

Two studies were performed during Ramadan, one in the UK (N=31) and the other in Libya (N=33). The aims were to assess some changes to lifestyle that are produced by fasting as well as effects due to culture. Subjects were studied on eight separate occasions: four control days (two before and two after Ramadan) and four days during the four weeks of Ramadan itself.

Nutritional intake during a simulated adventure race.

The objective of the study was to describe the food intake of adventure racers during a competition simulated in the laboratory. Ten male athletes with international experience in adventure races took part in the study. The experiment lasted 67 hr (total distance covered 477.

Circadian rhythms and their association with body temperature and time awake when performing a simple task with the dominant and non-dominant hand.

The two main aims of the study were to compare the dominant and non-dominant hand with regard to circadian rhythms of accuracy of performance at a task that required eye-hand coordination and sub-maximum muscle contraction, as well as to investigate if there were differences between the dominant and non-dominant hands in the associations between circadian rhythms of performance and core temperature and time awake. The task consisted of using a larger counter to flick a set of 20 smaller counters to land as near as possible to the center of a target. The nearer to the center of the target a counter landed, the higher the score awarded.

The effects of circadian rhythmicity and time-awake on a simple motor task.

The aim of the study was to assess if a simple motor task, one that required muscle contractions well below maximum, showed evidence of circadian changes and time-awake. The task consisted of using a larger counter to flick a number of smaller counters to land as near as possible to the center of a target. The closer a counter landed next to the center of the target, the higher the score obtained.