Circadian preference in Italy and India: A comparative study in young adults

Evening type negatively affects semen quality by deteriorating sperm morphology: Results from an infertility clinic

OBJECTIVE

The effect of sleep-related variables on the reproductive system has garnered attention in recent years. One of the mediators that reportedly plays an important role in the relationship between sleep disorders and the reproductive system is a disruption of the circadian rhythm. The aim of curent study is to investigate the effect of chronotype on morning semen quality.

STUDY DESIGN

Three-hundred and fourteen patients who applied to the infertility clinic were included in the study. The patients filled a socio-demographic data form. The "Pittsburg Sleep Quality Index (PSQI) was used to evaluate the sleep quality while the chronotypes of the patients were evaluated with the "Morningness -Eveningness-Questionnaire (MEQ)". Semen analyses and biochemical analysis for testosterone serum plasma level of all patients were performed.

RESULTS

Twenty-one patients were assigned as evening, 187 patients were assigned as intermediate, and 106 were assigned as morning chronotype. No statistically significant difference was identified in the comparison of the mean MEQ scores between patients with low and normal sperm concentrations(p = 0.884). A correlation analysis indicated the presence of a significant positive correlation between normal morphology and MEQ scores (r = 0.13, p < 0.05) and a negative corelation between the hours spent in bed and sperm concentration (r = -0.13, p < 0.05). A general linear model created with independent variables suggested that the presence of varicocele and MEQ scores had a significant effect on normal morphology.

CONCLUSION

The results of present study support that evening type could negatively affect sperm morphology; additionally, the time spent in bed also negatively affected sperm concentration.

Evidence for environment hypothesis: Cross-cultural measurement invariance of the composite scale of morningness across Bangladesh and Spain

Morningness-eveningness reflects individual differences in circadian functioning and is related to health and well-being. Cross-cultural comparison could facilitate understanding of the environmental factors affecting morningness-eveningness, which requires establishing cross-cultural validity of the relevant assessment tools. In this study, we applied the Composite Scale of Morningness (CSM) to Bangladeshi (n = 1015; 37.9% women) and Spanish (n = 1054; 73.2% women) university students (aged 18-27 years) to evaluate alternative factorial models of the CSM and to test its measurement invariance across cultures. Moreover, this study tested environment hypothesis, suggesting that higher average temperatures and lower latitudes would be related to greater morningness. From nine competing factorial models, a bifactor model with two specific factors (morning preference and morning affect) showed the best fit for both cultures. The two-factor bifactor model had full metric invariance with partial scalar and strict invariance across cultures. The Bangladesh-Spain comparison of the CSM scores revealed higher morningness in Bangladeshi students which supports the environment hypothesis. Overall, this research confirms that morningness-eveningness construct is perceived and interpreted similarly by the Bangladeshi and Spanish students. Importantly, this study highlights the effects of environmental factors including latitude and temperature on morningness-eveningness, and thus facilitates further cross-cultural morningness-eveningness research.

Gender differences in the relationships between sleep disturbances and academic performance among nursing students: A cross-sectional study

BACKGROUND

Sleep disturbances, such as insomnia, excessive daytime sleepiness, and poor-quality sleep, are common among nursing students and are closely linked with academic performance.

OBJECTIVES

To examine the prevalence of sleep disturbances and academic performances in male and female nursing students and to determine gender-specific effects on the relationship between sleep disturbances and academic performance.

DESIGN

A cross-sectional study design was adopted.

SETTINGS

This study was conducted in a school of nursing in Indonesia.

PARTICIPANTS

A total of 492 undergraduate students (103 males and 389 females) were included.

METHODS

Data pertaining to the biosociodemographic characteristics, Pittsburgh Sleep Quality Index, Insomnia Severity Index, Epworth Sleepiness Scale, Morningness-Eveningness Questionnaire, and Beck Depression Inventory were collected from July 1, 2018 to September 30, 2018. Academic performance was measured using grade point average of the academic year 2017-2018. A multivariate logistic regression model was used for data analyses.

RESULTS

The prevalence of poor sleep quality, insomnia, and daytime sleepiness was 66.0%, 45.6%, and 24.3%, respectively, in male nursing students and 71.5%, 52.4%, and 28.8%, respectively, in female nursing students. For circadian rhythm preferences, 66% male and 51.7% female nursing students were categorized as intermediate- and morning-type people, respectively. Insomnia was the only variable among sleep disturbances that significantly correlated with the risk of poor academic performance in female nursing students even after adjustment of covariates.

CONCLUSIONS

Sleep disturbances were highly prevalent among female and male nursing students, and insomnia was substantially associated with poor academic performance in female nursing students. Identifying sleep disturbances among nursing students and designing effective interventions to specifically target them are required to improve academic performance of female nursing students.

Chronotype-Dependent Changes in Sleep Habits Associated with Dim Light Melatonin Onset in the Antarctic Summer

Dim light melatonin onset (DLMO) is the most reliable measure of human central circadian timing. Its modulation by light exposure and chronotype has been scarcely approached. We evaluated the impact of light changes on the interaction between melatonin, sleep, and chronotype in university students (n = 12) between the Antarctic summer (10 days) and the autumn equinox in Montevideo, Uruguay (10 days). Circadian preferences were tested by validated questionnaires. A Morningness–Eveningness Questionnaire average value (47 ± 8.01) was used to separate late and early participants. Daylight exposure (measured by actimetry) was significantly higher in Antarctica versus Montevideo in both sensitive time windows (the morning phase-advancing and the evening phase-delaying). Melatonin was measured in hourly saliva samples (18–24 h) collected in dim light conditions (<30 lx) during the last night of each study period. Early and late participants were exposed to similar amounts of light in both sites and time windows, but only early participants were significantly more exposed during the late evening in Antarctica. Late participants advanced their DLMO with no changes in sleep onset time in Antarctica, while early participants delayed their DLMO and sleep onset time. This different susceptibility to respond to light may be explained by a subtle difference in evening light exposure between chronotypes.

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.

Prevalence and Risk Factors of Asthma and Allergy-Related Diseases among Adolescents (PERFORMANCE) study: rationale and methods

Despite a considerable number of international reports on allergic diseases among children, information about the prevalence and risk factors of asthma and allergy-related diseases among Indian adolescents is relatively sparse. The Prevalence and Risk Factors of Asthma and Allergy-Related Diseases among Adolescents (PERFORMANCE) study has been conceived to study the aetiology of asthma and allergic diseases including rhinoconjunctivitis, atopic eczema and food allergies among adolescents in West Bengal, India, using standardised methods and collaborations. The aims of the study are: 1) to estimate the prevalence and risk factors of asthma and allergic diseases among the adolescents residing in rural, suburban and urban areas of West Bengal; 2) to obtain information about the possible role of lifestyle factors (smoking, diet and physical activity) on the disease prevalence; and 3) to create a network for further investigation on social, environmental and genetic factors affecting the diseases. The PERFORMANCE study comprises two phases. The phase I study will investigate the prevalence and possible contributing factors of asthma and allergic diseases in a defined population. The phase II study will be performed as a follow-up of phase I to assess the incidence of asthma and allergic diseases.

The PERFORMANCE study: investigating the prevalence and risk factors of allergy and asthma among Indian adolescentshttp://ow.ly/jP2v30kmt8u

Cross-cultural validity of Morningness-Eveningness Stability Scale improved (MESSi) in Iran, Spain and Germany

Morningness-Eveningness Stability Scale improved (MESSi) is a newly constructed measure to assess circadian types and amplitude. In this study, we applied this measure to participants from three different countries: Germany, Spain and Iran. Confirmatory factorial analysis (CFA) of MESSi displayed mediocre fit in the three countries. Comparing increasingly stringent models using multigroup confirmatory factor analyses indicated at least partial measurement invariance (metric invariance) by country for Morning Affect and Distinctness subscales. Age was positively related to Morning Affect (MA), and negatively related to Eveningness (EV) and Distinctness (DI). Men reported higher MA than women, whereas women reported higher DI than men. Regarding country effect, Iranian participants reported highest MA compared to Spaniards and Germans, whereas Germans reported higher DI compared to Iranians and Spaniards. As a conclusion, our study corroborated the validity and reliability of MESSi across three different countries with different geographical and cultural characteristics.

Latitude affects Morningness-Eveningness: evidence for the environment hypothesis based on a systematic review

Morningness-eveningness (M/E) is an individual trait related to a person’s sleep-wake cycle and preference for morning or evening hours. The “environment hypothesis” suggests that M/E is dependent on environmental factors, such as latitude, mean average temperature and photoperiod. We here analyzed a large number of datasets to assess this effect based on a systematic review. Data were from a total of 87 datasets and 35,589 individuals based on 28 countries. Partial correlations correcting for age revealed significant relationships between M/E and latitude, mean yearly temperature, photoperiod and sunset. Evening orientation was related to higher latitude, longer days and later sunset. Morning orientation was related to higher average temperatures. Percentage of females and sunrise time had no significant influence. These variables (sunset, temperature, photoperiod) were then input in a general linear model. The full model showed an influence of age and of sunset on CSM scores, but not of photoperiod and average temperature. Sunset, therefore, seems to be the most important statistical predictor for the observed latitudinal gradient.

Extreme late chronotypes and social jetlag challenged by Antarctic conditions in a population of university students from Uruguay

In humans, a person’s chronotype depends on environmental cues and on individual characteristics, with late chronotypes prevailing in youth. Social jetlag (SJL), the misalignment between an individual׳s biological clock and social time, is higher in late chronotypes. Strong SJL is expected in Uruguayan university students with morning class schedules and very late entertainment activities. Sleep disorders have been reported in Antarctic inhabitants, that might be a response to the extreme environment or to the strictness of Antarctic life. We evaluated, for the first time in Uruguay, the chronotypes and SJL of 17 undergraduate students of the First Uruguayan Summer School on Antarctic Research, using Munich Chronotype Questionnaire (MCTQ) and sleep logs (SL) recorded during 3 phases: pre-Antarctic, Antarctic, and post-Antarctic. The midsleep point of free days corrected for sleep debt on work days (MSFsc,) was used as proxy of individuals’ chronotype, whose values (around 6 a.m.) are the latest ever reported. We found a SJL of around 2 h in average, which correlated positively with MSFsc, confirming that late chronotypes generate a higher sleep debt during weekdays. Midsleep point and sleep duration significantly decreased between pre-Antarctic and Antarctic phases, and sleep duration rebounded to significant higher values in the post-Antarctic phase. Waking time, but not sleep onset time, significantly varied among phases. This evidence suggests that sleep schedules more likely depended on the social agenda than on the environmental light–dark shifts. High motivation of students towards Antarctic activities likely induced a subjective perception of welfare non-dependent on sleep duration.

[Socio-demographic and food insecurity characteristics of soup-kitchen users in Brazil]

This study aimed to characterize users of a government soup-kitchen program and the association with family food insecurity, using a cross-sectional design and random sample of 1,637 soup-kitchen users. The study used a questionnaire with socioeconomic variables and the Brazilian Food Insecurity Scale, and measured weight and height. The chi-square test was applied, and the crude and adjusted prevalence ratios (PR) were calculated using Poisson regression. Prevalent characteristics included per capita income ranging from one-half to one minimum wage (35.1%), complete middle school (39.8%), and food security (59.4%). Users in the North of Brazil showed the worst data: incomplete primary school (39.8%), per capita income up to one-half the minimum wage (50.8%), and food insecurity (55.5%). Prevalence ratios for food insecurity were higher among users with per capita income up to one-fourth the minimum wage (p < 0.05). Income was the only variable that remained associated with higher prevalence of food insecurity in the adjusted PR. Knowing the characteristics of soup-kitchen users with food insecurity can help orient the program's work, location, and operations.

Reviewing the psychometric properties of contemporary circadian typology measures

The accurate measurement of circadian typology (CT) is critical because the construct has implications for a number of health disorders. In this review, we focus on the evidence to support the reliability and validity of the more commonly used CT scales: the Morningness-Eveningness Questionnaire (MEQ), reduced Morningness-Eveningness Questionnaire (rMEQ), the Composite Scale of Morningness (CSM), and the Preferences Scale (PS). In addition, we also consider the Munich ChronoType Questionnaire (MCTQ). In terms of reliability, the MEQ, CSM, and PS consistently report high levels of reliability (>0.80), whereas the reliability of the rMEQ is satisfactory. The stability of these scales is sound at follow-up periods up to 13 mos. The MCTQ is not a scale; therefore, its reliability cannot be assessed. Although it is possible to determine the stability of the MCTQ, these data are yet to be reported. Validity must be given equal weight in assessing the measurement properties of CT instruments. Most commonly reported is convergent and construct validity. The MEQ, rMEQ, and CSM are highly correlated and this is to be expected, given that these scales share common items. The level of agreement between the MCTQ and the MEQ is satisfactory, but the correlation between these two constructs decreases in line with the number of "corrections" applied to the MCTQ. The interesting question is whether CT is best represented by a psychological preference for behavior or by using a biomarker such as sleep midpoint. Good-quality subjective and objective data suggest adequate construct validity for each of the CT instruments, but a major limitation of this literature is studies that assess the predictive validity of these instruments. We make a number of recommendations with the aim of advancing science. Future studies need to (1) focus on collecting data from representative samples that consider a number of environmental factors; (2) employ longitudinal designs to allow the predictive validity of CT measures to be assessed and preferably make use of objective data; (3) employ contemporary statistical approaches, including structural equation modeling and item-response models; and (4) provide better information concerning sample selection and a rationale for choosing cutoff points.