Association between circadian rhythm and sleep quality among nursing interns: A latent profile and moderation analysis

The relationship between circadian type and physical activity as predictors of cognitive performance during simulated nightshifts: A randomised controlled trial

Nightshift is associated with impaired cognitive performance on many tasks, yet performance is also moderated by individual differences. We investigated the effect of circadian type (two factors: flexible-rigid, and languid-vigour), and the efficacy of a novel countermeasure, breaking up sitting with light-intensity physical activity, in the context of nightshift performance. Thirty-three healthy adults (age M ± SD: 24.3 ± 4.6 y; 19 females) participated in a sleep laboratory study over five consecutive simulated nightshifts (2200-0600 h). Sleep opportunities occurred at 0800-1700 h. Participants were randomised to a sedentary (SIT; n = 14), or "breaking-up" sitting (BREAK; n = 19) condition. BREAK participants completed 3 min of light-intensity walking every 30 min at 3.2 km/h, while SIT participants remained seated. Every 2 h during nightshift, participants completed the Psychomotor Vigilance Task (mean RRT), Stroop Task, and Digit Symbol Substitution Task. Participants completed the revised Circadian Type Inventory which categorises individuals on a rigid-flexible scale and a languid-vigorous scale (rigid; n = 12, flexible; n = 11; languid; n = 11, vigorous n = 13). Linear mixed models showed a significant 3-way interaction between Nightshifts (1-5), Condition (SIT, BREAK), and flexibility-rigidity for mean RRT (p = 0.03) only. Flexible types in the BREAK condition had better performance than rigid BREAK, rigid SIT, and flexible SIT over five nights, with performance marginally worse on the first night for all participants apart from rigid SIT. Linear mixed models showed a significant 2-way interaction between Nightshifts (1-5), and flexibility-rigidity for percentage accuracy on the Stroop task, and a significant 2-way interaction between Nightshifts (1-5), and languid-vigour for response time on the Stroop task. Accuracy worsened for rigid types, while response time on the Stroop task improved for languid types over five nights. No other significant differences were found. Breaking up sitting with light-intensity physical activity maintained sustained attention for flexible circadian types across all five experimental nightshifts. Both rigidity and languidity moderated trends in performance, though whether these differences have meaningful real-world implications must be explored further. Our results indicate that circadian type classifications should be accounted for in breaking up sitting interventions overnight.

Social anxiety, loneliness, and mobile phone addiction among nursing students: latent profile and moderated mediation analyses

BACKGROUND

The overutilization of mobile devices by nursing students has been found to adversely affect their physical and cognitive health, potentially impeding the cultivation of a proficient nursing workforce. Previous research has identified social anxiety and loneliness as influential contributors to mobile phone addiction, but the relationship between these three factors has not been extensively examined. The objective of this research was to investigate the role of loneliness in mediating the relationship between social anxiety and mobile phone addiction, as well as the moderating influence of sleep duration on the relationship between social anxiety, loneliness, and mobile phone addiction among nursing students.

METHODS

We enrolled 437 students from the Be Resilient to Nursing Career program (BRNC) between October and December 2023. Surveys were employed to evaluate the levels of social anxiety, loneliness, and mobile phone addiction among nursing students. Three types of analyses were performed: latent profile analysis, mediation analysis, and moderation analysis.

RESULTS

The following three profiles of social anxiety were identified: low social anxiety (23.8%), middle social anxiety (42.8%), and high social anxiety (33.4%). The significant mediating effect of loneliness in the relationship between social anxiety based on latent profile analysis and mobile phone addiction was observed (SE = 0.709, 95%CI = 1.821, 4.618; SE = 0.561, 95%CI = 1.161, 3.345, respectively). The moderating role of sleep duration between social anxiety, loneliness, and mobile phone addiction was not significant (P > 0.05).

CONCLUSION

Heterogeneity exists in social anxiety among nursing students. Loneliness serves as a significant mediating factor between social anxiety and mobile phone addiction. The moderating influence of sleep duration should be validated in future research.

Personality and sleep quality among nursing interns: Traditional Chinese medicine constitution as a mediator and sedentary time as a moderator

Aims

This study investigated whether the relationship between neuroticism and sleep quality in nursing interns is mediated by traditional Chinese medicine (TCM) constitution. In addition, the study examined whether sedentary behaviour affects this mediating model.

Background

The importance of sleep quality for nursing interns cannot be overstated. Previous studies have demonstrated that neuroticism negatively affects sleep quality. However, little is known about the path of the relationship between neuroticism and sleep quality among nursing interns.

Design

A cross-sectional study was conducted in Central and South China.

Methods

A total of 630 nursing interns participated in this study. Neuroticism, TCM constitution, sleep quality, and sedentary behaviour were measured using reliable and valid questionnaires. Data were analysed using the PROCESS macro in SPSS.

Results

Neuroticism significantly predicted the Pittsburgh Sleep Quality Index (PSQI; β = 0.144, P < 0.001). Neuroticism exerted a significant indirect effect on the PSQI through gentleness and damp heat constitution (β = 0.265, 95 % CI [0.214, 0.315]). In addition, sedentary time moderated this mediation model. Sedentary time marginally moderated the direct pathway from neuroticism to the PSQI (B = -0.025, 95 % CI [-0.046, -0.004]) and the pathway from neuroticism to the damp heat constitution (B = 0.175, 95 % CI [0.021, 0.329]) in the nursing interns.

Conclusion

TCM constitution mediates the relationship between neuroticism and sleep quality. Given the moderating effect of sedentary behaviour, targeting sedentary behaviour can be an effective approach to improve the sleep quality of nursing interns.

Human immune and metabolic biomarker levels, and stress-biomarker associations, differ by season: Implications for biomedical health research

Although seasonal changes in physiology are well documented, little is known about how human immune and metabolic markers vary across seasons, and no studies have examined how stress → health biomarker associations differ across the year. To investigate these issues, we analyzed data from 2118 participants of the Midlife in the United States (MIDUS) study to determine whether there were differences in (a) levels of 19 immune and metabolic markers, and (b) the association between perceived stress and each biomarker across the year. Results of component-wide boosted generalized additive models revealed seasonal patterning for most biomarkers, with immune proteins generally peaking when days were shorter. Moreover, whereas levels of hemoglobin A1C rose from late fall to spring, triglycerides were elevated in the summer and fall, and high-density lipoprotein decreased steadily from January to December. Urinary cortisol and cortisone exhibited opposite patterns, peaking at the beginning and end of the year, respectively. Most critically, we found that the effects of perceived stress on 18 of the 19 health biomarkers assessed varied by month of measurement. In some cases, these differences involved the magnitude of the stress → biomarker association but, in other cases, it was the direction of the effect that changed. Studies that do not account for month of biomarker assessment may thus yield misleading or unreproducible results.

Personality portraits, resilience, and professional identity among nursing students: a cross-sectional study

BACKGROUND

The lack of professional identity can impede the transition from nursing students to qualified nurses and exacerbate the shortage of health care professionals. Personality is important to resilience-building and professional identity development in nursing students. However, the associations among personality, resilience, and professional identity are less explored. The study aims to identify latent subtypes of personality, to evaluate the mediating role of resilience between personality and professional identity in nursing students, and to provide practical guidance for educators' subsequent interventions with nursing students' professional identity.

METHODS

1397 nursing students were recruited from Be Resilient to Nursing Career (BRNC) between October 2020 and April 2022 by cluster sampling from 4 universities in China. NEO Five-Factor Inventory, 10-item Connor-Davidson Resilience Scale, and Professional Identity Questionnaire for Undergraduate Students were administered. Analyses of latent profiles and mediations were performed.

RESULTS

Three latent personality types were identified: Over-sensitivity (35.4%), Ordinary (53.8%), and Flexibility (10.8%). Nursing role model was found to be a significant indicator of personality (Ordinary as ref, Over-sensitivity: OR = 0.73, 95% CI: 0.57-0.93, P = 0.010; Flexibility: OR = 1.85, 95% CI: 1.29-2.65, P = 0.001). The association between personality portraits and professional identity were significantly mediated by resilience (P < 0.05).

CONCLUSIONS

There exists heterogeneity in nursing students' personality. Resilience plays a significant role in mediating the relationship between personality and professional identity.

Latent profile analysis of depression in US adults with obstructive sleep apnea hypopnea syndrome

Objective

This study used latent profile analysis to explore the level of depression among US adults with obstructive sleep apnea hypopnea syndrome (OSAHS) symptoms and to identify different latent categories of depression to gain insight into the characteristic differences between these categories.

Methods

The data of this study were obtained from the National Health and Nutrition Examination Survey (NHANES) database, and the subjects with OSAHS symptoms were aged 18 years and older. The latent profile analysis (LPA) method was used to fit the latent depression categories in subjects with OSAHS symptoms. The chi-square test, rank sum test, and binary logistic regression were used to analyze the influencing factors of depression subgroups in subjects with OSAHS symptoms.

Results

Three latent profiles were identified: low-level (83.7%), moderate-level (14.5%) and high-level (1.8%) depression. The scores of 9 items in the high-level depression group were higher than those in the other two groups. Among them, item 4 "feeling tired or lack of energy" had the highest score in all categories.

Conclusion

Depression in subjects with OSAHS symptoms can be divided into low-level, moderate-level and high-level depression. There are significant differences among different levels of depression in gender, marital status, PIR, BMI, smoking, general health condition, sleep duration and OSAHS symptom severity.

Effects of exercise timing and intensity on physiological circadian rhythm and sleep quality: a systematic review

PURPOSE

Humans show near-24-h physiological and behavioral rhythms, which encompass the daily cycle of sleep and wakefulness. Exercise stimulates circadian rhythms, including those of cortisol, melatonin, and core body temperature, and affects sleep quality. We systematically reviewed studies that examined the effects of exercise intensity and timing on physiological circadian rhythms and sleep quality.

METHODS

In this systematic review, we used the online databases PubMed, Science Direct, Web of Science, and Embase. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two independent and experienced systematic reviewers performed the search and selected relevant studies. The participant, intervention, comparison, and outcome characteristics were: (1) adults; (2) exercise treatment; (3) no exercise treatment or different types of exercise (pre-exercise baseline); (4) cortisol, melatonin, or core body temperature measurement, and subjective or objective sleep quality assessments.

RESULTS

We identified 9 relevant articles involving 201 participants (77.1% of whom were male). Our review revealed that short-term evening exercise delayed melatonin rhythm and increased nocturnal core body temperature; however, no negative effects on non-rapid eye movement sleep and sleep efficiency were observed. Moreover, no differences in sleep quality were observed between acute high-intensity and moderate-intensity exercises. With long exercise durations, the core body temperature tended to increase and return to baseline levels at 30-120 min.

CONCLUSION

Our review showed that short-term evening exercise and high-intensity exercise did not have a significant negative effect on sleep quality but physiological circadian rhythm tended to alter. Longterm morning exercise tended to decrease cortisol concentrations after awakening and improve sleep quality. Future studies should examine the effects of long-term exercise timing and intensity on circadian rhythm and sleep.

Latent profile analysis for health-related quality of life, sleep quality, morning and evening type, and internet addiction among medical students

Health-related quality of life, sleep quality, morning and evening types, and internet addiction are of significant importance to the development of medical students, yet they have rarely been studied. Taking this into consideration, the study aimed to confirm latent profiles in health-related quality of life, sleep quality, morning and evening types, and internet addiction in medical students and investigate the characteristics of participants in each profile to provide suggestions for students' health. This was an observational cross-sectional study including 1221 medical student subjects at China Medical University in 2019. Multiple correspondence analysis was the initial step to verify the correspondence, dispersion, and approximation of variable categories. Latent profile analysis was used to identify the multiple correspondences between the levels of variables. Three profiles were found, including: (1) The Low sleep quality profile was characterized by the lowest sleep quality among the three existing profiles. (2) The High health-related quality of life and Low internet addiction profile was characterized by the highest level of health-related quality of life but the lowest level of internet addiction. (3) The Low health-related quality of life and High internet addiction profile was characterized by the highest standardized values of internet addiction but the lowest standardized values of health-related quality of life. This study had important implications for improving student health and supported the medical universities and hospitals in implementing targeted policies based on distinctive student characteristics.

Associations between Nonrestorative Sleep, Perceived Stress, Resilience, and Emotional Distress in Freshmen Students: A Latent Profile Analysis and Moderated Mediation Model

Objective. This study aims to explore the mediation role of perceived stress between nonrestorative sleep (NRS) and emotional distress, as well as the moderation role of resilience among NRS, perceived stress, and emotional distress in university students. Method. We recruited 851 students from the Be Resilient to Nursing Career program (BRNC, registration number: NFYKDX002) in June 2022. Nonrestorative sleep scale (NRSS), 10‐item perceived stress scale (PSS‐10), 10‐item Kessler psychological distress scale (K10), and 10‐item Connor–Davidson resilience scale (CD‐RISC‐10) were administered through a paper questionnaire. Latent profile analysis and moderated mediation analysis were performed. Results. Three profiles of perceived stress were identified: high ability‐low stress (24.5%), middle ability‐high stress (65.0%), and low ability‐middle stress (10.5%). The mediation role of perceived stress between NRS and emotional distress was significant (SE = 0.025; 95% confidence interval = −0.369, −0.269). The moderation role of resilience among NRS, perceived stress, and emotional distress was not significant. Conclusion. Heterogeneity exists in freshmen students’ perceived stress. Perceived stress plays a significant mediating role between NRS and emotional distress, while resilience cannot significantly moderate the associations among NRS, perceived stress, and emotional distress. The trial is registered with ChiCTR2000038693.