We present a study of Per3 expression in six different tissues of the non-human primate Cebus apella (capuchin monkey). The aim of this study was to verify whether the expression of the Per3 gene in different tissues of capuchin monkey occurs in a circadian pattern, its phase and the phase relationships between these different tissues during the 24 h of a day. We observed that gene expression oscillated in all of the tissues studied during this time period, although only the liver and muscle presented a robust circadian pattern. This preliminary study highlights the possibility of using Cebus apella as a model to study circadian rhythms at the gene expression level and opens an opportunity for future researches.
Keywords: Circadian rhythms, Circadian expression, Per3 gene, Primate, Capuchin monkey
OBJECTIVE: To identify the prevalence and associated factors of overweight and obesity in Brazilian commercial airline pilots.
METHODS: An observational, cross-sectional study involving 1198 Brazilian commercial airline pilots with a sampling power > 80% (β=20%) and confidence level of 95% (α=5%) was carried out. The pilots completed an on-line questionnaire collecting data on sociodemographics, work, health, lifestyle and sleep. Poisson regression, with robust variance (stepwise forward technique), was employed to analyze the factors associated with excess weight (overweight and obesity). The models were adjusted for the variables age, marital status and education. The data were analyzed using the STATA 12.0 program.
RESULTS: The prevalence of overweight among the pilots was 53.7% and of obesity was 14.6%. The probability of being overweight was highest among pilots working night shifts for 6-10 years and that had difficulty relaxing after work, where perceived morningness was a protective factor. Risk factors for obesity included working night-shifts for 6-10 years, having difficulty relaxing after work, sleeping <6h on days off, having other diagnosed diseases, and practicing < 150 min/week of physical exercise.
CONCLUSION: It was concluded that the prevalence of overweight and obesity among the commercial airline pilots was high and represents a public health problem in this population. Excess weight was associated with time working night-shifts, difficulty relaxing after work, inadequate sleep on days off, having other chronic diseases, and physical inactivity. In this context, nutritional status can be regarded as the result of dynamic and complex interactions promoted by occupational, sleep and health factors.
Keywords: Excess weight, Work Sleep, Air pilots
Sleep-related health disorders are increasing worldwide; diagnosis and treatment of such sleep diseases are commonly invasive and sometimes unpractical or expensive. Actigraphy has been recently introduced as a tool for the study of sleep and circadian disorders; however, there are several devices that claim to be useful for research and have not been thoroughly tested. This comparative study provides activity, sleep and temperature information regarding several of the most commonly used actigraphers: Micro-Mini Motion Logger; Act Trust; Misfit Flash; Fitbit Flex & Thermochron.
Twenty-two healthy young subjects were assessed with five different commercial actigraphs (MicroMini Motionlogger Watch, Condor Act Trust, MisFit Flash and Fitbit Flex) and a temperature recorder (Thermochron), and also completed a sleep diary for a week. There were not significant differences in the analysis of rest-activity pattern between devices. Temperature rhythm comparison between the Act Trust and the Thermochron showed significant differences in rhythm percentage (p < 0.05) and mesor (p < 0.0563) but not in amplitude or acrophase.
Although data accessibility and ease of use was very different for the diverse devices, there were no significant differences for sleep onset, total sleep time and sleep efficiency recordings, where applicable. In conclusion, depending on the type of study and analysis desired (as well as cost and compliance of use), we propose some relative advantages for the different actigraphy/temperature recording devices.
Keywords: Actigraphy, Sleep, Circadian, Temperature, Rest-activity, Ambulatory monitoring
South American subterranean rodents are mainly described as solitary and mutual synchronization was never observed among individuals maintained together in laboratory. We report that a single birth event was capable of disrupting the robust nocturnal activity rhythm of singly housed tuco-tucos from north-west Argentina. “Around-the-clock activity” was displayed by 8 out of 13 animals whose cages were closer to the newborn pups. However, experimental exposure to a pup vocalization did not produce a similar effect on the rhythms of adult animals. Our results indicate an effect of social interaction in the expression of biological rhythms even in solitary animals.
Keywords: Ctenomyidae, Tuco-tuco, Social synchronization, Around-the-clock activity, Circadian rhythm
Delirium is associated with circadian rhythm disruption. In this study we have explored whether circadian variation of melatonin is an indicator for delirium. Melatonin levels were determined from the first day of hospitalization and up to three days after the onset of delirium. Patients who did not developed delirium exhibited a daily melatonin rhythm, while in patients that developed delirium, the melatonin rhythm was lost and mean melatonin levels were found decreased as early as three days before the diagnosis of delirium, indicating that on arrival to the hospital circadian melatonin disruption can be used as an indicator of delirium.
Keywords: Human, Circadian rhythm, Sleep, Dementia, Geriatric
Physical activity has been recommended as a strategy for improving sleep. Nevertheless, physical effort at work might not be not the ideal type of activity to promote sleep quality. The aim of this study was to evaluate the effects of type of job (low vs. high physical effort) and life-style on sleep of workers from an Amazonian Extractivist Reserve, Brazil. A cross-sectional study of 148 low physical activity (factory workers) and 340 high physical activity (rubber tappers) was conducted between September and November 2011. The workers filled out questionnaires collecting data on demographics (sex, age, occupation, marital status and children), health (reported morbidities, sleep disturbances, musculoskeletal pain and body mass index) and life-style (smoking, alcohol use and practice of leisure-time physical activity). Logistic regression models were applied with the presence of sleep disturbances as the primary outcome variable. The prevalence of sleep disturbances among factory workers and rubber tappers was 15.5% and 27.9%, respectively. The following independent variables of the analysis were selected based on a univariate model (p < 0.20): sex, age, marital status, work type, smoking, morbidities and musculoskeletal pain. The predictors for sleep disturbances were type of job (high physical effort); sex (female); age ( > 40 years), and having musculoskeletal pain (≥5 symptoms). Rubber tapper work, owing to greater physical effort, pain and musculoskeletal fatigue, was associated with sleep disturbances. Being female and older than 40 years were also predictors of poor sleep. In short, these findings suggest that demanding physical exertion at work may not improve sleep quality.
Keywords: Sleep disturbances, Work, Life style, Musculoskeletal pain, Physical activity
Photic and non-photic environmental factors are suggested to modulate the development of circadian rhythms in infants. Our aim is to evaluate the development of biological rhythms (circadian or ultradian) in newborns in transition from Neonatal Intensive Care Units (NICU) to home and along the first 6 months of life, to identify masking and entraining environment factors along development.
Ten newborns were evaluated in their last week inside the NICU and in the first week after being delivered home; 6 babies were also followed until 6 months of corrected age. Activity, recorded with actimeters, wrist temperature and observed sleep and feeding behavior were recorded continuously along their last week inside the NICU and in the first week at home and also until 6 months of corrected age for the subjects who remained in the study.
Sleep/wake and activity/rest cycle showed ultradian patterns and the sleep/wake was strongly influenced by the 3 h feeding schedule inside the NICU, while wrist temperature showed a circadian pattern that seemed no to be affected by environmental cycles. A circadian rhythm emerges for sleep/wake behavior in the first week at home, whereas the 3 h period vanishes. Both activity/rest and wrist temperature presented a sudden increase in the contribution of the circadian component immediately after babies were delivered home, also suggesting a masking effect of the NICU environment.
We found a positive correlation of postconceptional age and the increase in the daily component of activity and temperature along the following 6 months, while feeding behavior became arrhythmic.
Keywords: Circadian, Rhythm, Newborn, Sleep, Wrist-temperature, Environment