State-trait arousal and daytime sleepiness after sleep restriction

How emotions impact sleep: A quantitative review of experiments

Although sleep and emotional processes are recognized as mutually dependent, the causal impact of emotions on sleep has been comparatively neglected. To appraise evidence for the causal influence of emotions on sleep, a meta-analysis of the existing experimental literature evaluated the strength, form, and context of experimental effects of emotion inductions on sleep parameters (k = 31). Quality of experiments was evaluated, and theoretically-relevant features were extracted and examined as moderating factors of observed effects (i.e., sleep parameter, design, sleep context, types of emotion inductions and emotions). Random-effect models were used to aggregate effects for each sleep parameter, while-mixed effect models examined moderators. There was a significant impact of emotion inductions on delayed sleep onset latency (D = 3.36 min, 95%CI [1.78, 4.94], g = 0.53), but not other parameters. There was little evidence of publication bias regarding sleep-onset latency effect, the studies overall were heterogeneous, sometimes of limited methodological quality, and could only detect moderate-to-large impacts. The findings supported the hypothesis that negative emotions delayed sleep onset, but evidence regarding other sleep parameters was inconclusive. The results call for more targeted investigation to disambiguate distinct features of emotions and their import for sleep.

Hyperarousal Scale: Italian Cultural Validation, Age and Gender Differences in a Nonclinical Population

Objectives. Studies on hyperarousal have increasingly developed in the last decade. Nevertheless, there are still very few valid measures of hyperarousal. The aim of the study is to verify the psychometric properties of the Italian version of the Hyperarousal Scale (H-Scale), in order to provide researchers with a valid measure for the target population. Method. The questionnaire was translated, back-translated, pre-tested, and cross-culturally adapted. Subsequently, the Italian version of the H-Scale, the Anxiety Sensitivity Index (ASI-3) and the Health Survey Questionnaire (SF-36) were administered to 982 adults, 456 males and 526 females, aged from 18 to 80 years (M = 35.61 ± 12.47). Results. Cronbach’s alpha of the translated H-Scale was 0.81. Furthermore, positive correlations with the ASI-3 and negative correlations with the SF-36 emerged. The H-Scale is also sensitive to catch age and gender differences. Conclusions. The Italian version of the H-Scale demonstrated good reliability and validity. Its sufficient discriminative and evaluative psychometric properties provide the theoretical evidence for further application in evidence-based research studies.

Cardiopulmonary coupling spectrogram as an ambulatory clinical biomarker of sleep stability and quality in health, sleep apnea, and insomnia

STUDY OBJECTIVES

Ambulatory tracking of sleep and sleep pathology is rapidly increasing with the introduction of wearable devices. The objective of this study was to evaluate a wearable device which used novel computational analysis of the electrocardiogram (ECG), collected over multiple nights, as a method to track the dynamics of sleep quality in health and disease.

METHODS

This study used the ECG as a primary signal, a wearable device, the M1, and an analysis of cardiopulmonary coupling to estimate sleep quality. The M1 measures trunk movements, the ECG, body position, and snoring vibrations. Data from three groups of patients were analyzed: healthy participants and people with sleep apnea and insomnia, obtained from multiple nights of recording. Analysis focused on summary measures and night-to-night variability, specifically the intraclass coefficient.

RESULTS

Data were collected from 10 healthy participants, 18 people with positive pressure-treated sleep apnea, and 20 people with insomnia, 128, 65, and 121 nights, respectively. In any participant, all nights were consecutive. High-frequency coupling (HFC), the signal biomarker of stable breathing and stable sleep, showed high intraclass coefficients (ICCs) in healthy participants and people with sleep apnea (0.83, 0.89), but only 0.66 in people with insomnia. The only statistically significant difference between weekday and weekend in healthy subjects was HFC duration: 242.8 ± 53.8 vs. 275.8 ± 57.1 minutes (89 vs. 39 total nights), F(1,126) = 9.86, p = .002.

CONCLUSIONS

The M1 and similar wearable devices provide new opportunities to measure sleep in dynamic ways not possible before. These measurements can yield new biological insights and aid clinical management.

Social support moderates the effects of stress on sleep in adolescents

Academic expectations and demands become primary sources of stress during adolescence, negatively affecting sleep. To cope with stress, adolescents may turn to social support figures. The present study tested the extent of main and moderating effects of various sources of social support on the association between stress and sleep. Adolescents (n = 202, meanage 14.6 years, standard deviation = 0.71) reported on academic stress, sleep, and support using questionnaires during a low- and high-stress period, defined by the absence or presence of examinations, respectively. Inquiries were made regarding social support from parents, friends, and class supervisor. During both stress periods, academic stress was associated negatively with sleep quality and positively with sleep reduction. Social support increased sleep quality and lowered sleep reduction. In addition, social support moderated the effects of academic stress on sleep, thus improving sleep quality and lowering sleep reduction. Moderating effects were stronger during a period of high stress. The present study showed that adolescents can benefit from stress moderation through social support by improvements of sleep quality and sleep reduction. Such moderating effects should be taken into account when studying stress and sleep. Implications and recommendations based on these findings are discussed.