Evaluation of behavioral states among morning and evening active healthy individuals

Circadian rhythms and objective measures of physical activity among middle-aged and older adults in Taiwan

BACKGROUND

To identify the association between daytime activity with objectively monitor and subjective variables at a different time-zone of day as well as the sex differences.

METHODS

Participants aged 50 years and older living in the community in Taiwan were recruited. The activity was measured by wearable actigraphy devices, diaries, and self-reported questionnaires. The study used nonparametric analysis to examine the association between mean activity level and demographic and subjective measurement variables.

RESULTS

Among the 55 participants enrolled in the study, data of 34 (62 %) participants who meet the criteria that wore a wearable actigraphy device for at least 7 completed days were analyzed. There is no significant relationship between each demographics and subjective measurement variables. However, actigraphy counts are significantly related to female's nutrition (Z = -2.367, p = 0.017*), and male's retirement status (Z = -2.132, p = 0.033*).

CONCLUSIONS

The activity in morning is highest of the day with significant correlation to evening activities. Moreover, actigraphy counts that indicating objective measure of physical activity in female is significantly related to physiological variables (nutritional status), while male are predicted by social variables (retired status).

Patterns in behavioural sleep variables and social jetlag in elderly people of Western Odisha

In humans, sleep is an essential physiological process for life and survival. The main objective of the current study is to determine the behavioural sleep patterns and social jetlag in elderly adults. The second objective is to define the relationship among subjective sleep quality, mid-sleep timings, social jetlag, and sunlight exposure. We recruited 945 female and 1047 male participants aged ≥ 60 years from 65 rural villages in the Sambalpur district of Odisha, India. The Munich Chrono Type Questionnaire (MCTQ) is a self-reported questionnaire that measures a person's behavioral sleep variables, including social jetlag and chronotype, whereas the Pittsburgh Sleep Quality Index (PSQI) measures the subjective sleep quality of an individual. We employed MCTQ and PSQI to obtain behavioral sleep variables and subjective sleep quality in the recruited subjects. The behavioral sleep variables were compared using a paired t-test on both work and work-free days. In addition, the behavioral sleep variables as a function of gender were compared using an independent Student's t-test. In the current study, most of the elderly individuals reported both midpoint of sleep on workdays (MSW) and midpoint of sleep on work-free days (MSF) between 00:01-03:00. The averages of mid-sleep timings between workdays and work-free days were not statistically significant. Data on MSFsc (midpoint of sleep on work-free days sleep corrected) indicated that most elderly adults (99.6%) are morning type; they go to bed early and wake up early. The elderly participants from the rural population of Sambalpur district in western Odisha had the least social jetlag and exhibited good subjective sleep quality. It would be worthwhile to find out the determinants of these positive features apropos social jetlag and behavioural sleep patterns.

Effects of altitude on chronotype orientations in relation to cardiorespiratory and hematological quantities of college students in Ethiopia

BACKGROUND

The mechanism by which Ethiopians adapt to altitude is quite unique compared to other Highlanders with respect to increased oxygen saturation of hemoglobin. Although the effects of altitude on cardiorespiratory and hematological quantities on athletics performances are well known, but there is little information about its underlying effect on chronotype orientations.

METHODS

In this cross-sectional study 60 male college students with mean age 20±1.3 years from high and low altitude regions living in a tropical setting in Ethiopia were included. The participants' chronotype was determined using the self-administered Horne and Ostberg Morningness-Eveningness Questionnaires (MEQ). Measurements and estimations of hematological and cardiorespiratory parameters were performed from 7:00-9:00 AM, East African time zone, in order to minimize any variations that might occur in the course of the day. A multivariate binary logistic regression model was fitted to analyze the underlying chronotype predictors.

RESULTS

28 (93.9%) of participants from high altitude were mainly intermediate type (I-type) dominant with (MEQ = 42-58). While, 16 (55.2%) of participants from low altitudes were morning type (M-type) dominant chronotype with (MEQ = 59-69). Our main finding confirmed that altitude is an independent predictor of chronotype orientations of the participants (p<0.015). Thus, the results of the multivariate analysis seem to indicate that, participants from low and high altitudes may be uniquely oriented towards either M-type or I-type chronotype respectively (adjusted odds ratio [AOR] 4.772, 95% CI = 3.748-4618458). However, no significant difference on cardiorespiratory and hematological quantities between I-type and M-type chronotype of students from low altitude living in the same setting was reported (p > 0.05).

CONCLUSION

Our finding, reported for the first time that, the human chronotype varies according to the altitude, with no underlying effect of cardiorespiratory and hematological quantities.

Chronotype preferences of college students from varied altitude backgrounds in Ethiopia

The purpose of this study was to compare chronotype preferences of college students from high- and low-altitude backgrounds living in a tropical setting of Ethiopia. Chronotype (morningness-eveningness) is a preference for a given time of day for physical or mental activities. The present cross-sectional study employed Horne and Osteberg Morningness-Eveningness Questionnaires to evaluate chronotype preferences. The chronotype preference of 264 male college students from varied altitude backgrounds indicated significant differences (p < 0.001). Our findings confirm our hypothesis, of the prevalence of M-types dominant chronotype among college students at low than high altitude. However, we did not confirm our second hypothesis, since students from high-altitude backgrounds were generally I-type dominant chronotype. Similarly, students' academic performances from low- compared to high-altitudes backgrounds also indicated significant differences (p < 0.003). Better academic performances were seen in students with I-type chronotype orientations from high altitudes.

Depression scores associate with chronotype and social jetlag in a rural population

In public health, mood disorders are among the most important mental impairments. Patients with depressive episodes exhibit daily mood variations, abnormal patterns in sleep-wake behavior, and in the daily rhythms of several endocrine-metabolic parameters. Although the relationship between the sleep/circadian processes and mood disorders is poorly understood, clock-related therapies, such as light therapy, sleep deprivation, and rigid sleep schedules, have been shown to be effective treatments. Several studies investigated the relationship between circadian phenotype (chronotype) and depression. These focused mainly on urban populations and assessed diurnal preferences (Morningness-Eveningness score) rather than the actual timing of sleep and activity. Here, we used the Beck Depression Inventory (BDI) in an essentially rural population (N?=?4051), and investigated its relation to circadian phenotype (chronotype and social jetlag), assessed with the Munich Chronotype Questionnaire (MCTQ). In our study design, we (i) normalized both chronotype and BDI scores for age and sex (MSF(sas) and BDI(as), respectively); (ii) calculated individual social jetlag (misalignment of the biological and social time); and (iii) investigated the relationship between circadian phenotypes and BDI scores in a population homogeneous in respect to culture, socioeconomic factors, and daily light exposure. A 15.65% (N?=?634) of the participants showed mild to severe depressive BDI scores. Late chronotypes had a higher BDI(as) than intermediate and early types, which was independent of whether or not the participants were smokers. Both chronotype and BDI(as) correlated positively with social jetlag. BDI(as) was significantly higher in subjects with >2?h of social jetlag than in the rest of the population?again independent of smoking status. We also compared chronotype and social jetlag distributions between BDI categories (no symptoms, minimal symptoms, and mild to severe symptoms of depression) separately for men and women and for four age groups; specifically in the age group 31?40 yrs, subjects with mild to severe BDI scores were significantly later chronotypes and suffered from higher social jetlag. Our results indicate that misalignment of circadian and social time may be a risk factor for developing depression, especially in 31- to 40-yr-olds. These relationships should be further investigated in longitudinal studies to reveal if reduction of social jetlag should be part of prevention strategies. (Author correspondence: karla.allebrandt@med.uni-muenchen.de ).

Síndrome do comer noturno: aspectos conceituais, epidemiológicos, diagnósticos e terapêuticos

O comportamento e o padrão alimentar são complexos, envolvendo aspectos metabólicos, fisiológicos e ambientais, e apresentando ritmicidade circadiana, herdada e espécie específica, sendo a humana essencialmente diurna. Este estudo tem como objetivo descrever a Síndrome do Comer Noturno, caracterizada por um atraso circadiano do padrão alimentar, mediado por alterações neuroendócrinas ao estresse. Procedeu-se à revisão da bibliografia existente, a partir do exame de artigos publicados pela literatura internacional nas bases de dados dos sites Pubmed, Lilacs, Sirus, referentes ao período de 1955 até as últimas publicações em 2007. Realizou-se um levantamento bibliográfico usando os seguintes descritores: night eating syndrome, sleep, circadian rhythm, appetite, nocturnal eating. Foram localizados 74 artigos e destes foram selecionados 26, cujo tema central era a Síndrome do Comer Noturno. Apesar dos estudos realizados, ainda existe longo percurso a ser percorrido para compreender a gênese da Síndrome do Comer Noturno e as relações intrínsecas desta com outros processos fisiopatogênicos. Tendo em conta que esta síndrome está vinculada ao controle da fome e da saciedade e à dessincronização entre o ritmo alimentar e o ritmo sono/vigília, a compreensão do seu processo gênico poderá demonstrar o impacto da dessincronização dos ritmos circadianos da alimentação no processo saúde-doença, e auxiliar a compreensão de fatores implicados no índice crescente de obesidade da sociedade moderna.