The Circadian Disruption Index: development, validation, and responsiveness to circadian health education

Circadian rhythm disruption and multiple sclerosis: The role of affective symptoms and temperamental traits.

Systematic assessment of mood and circadian rhythms may offer a more comprehensive framework for identifying clinically relevant chronobiological disruption in patients with multiple sclerosis.

Circadian phenotype is associated with diurnal variation in human exercise performance.

It is demonstrated that endurance exercise performance is enhanced in the evening compared with the morning and suggested that behavioural markers of circadian phenotype are associated with the magnitude of diurnal variation in performance.

Screen Exposure, Circadian Rhythm, Sleep, Physical Activity, and Health Anxiety in University Students During Online Education

Aim: This study aimed to examine the associations between screen exposure, sedentary behavior, circadian rhythm, sleep, physical activity, and health anxiety among university students during the online education period.Method: A total of 130 healthy university students participated. Data on socio-demographic characteristics, sleep onset latency, wake-up times, nighttime light exposure, and screen time were collected. Participants also completed the Morningness-Eveningness Questionnaire, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the International Physical Activity Questionnaire (IPAQ), and the Short Health Anxiety Inventory.Results: The sample included 101 females (78%) and 29 males (22%). Weak positive correlations were found between wake-up time and sleep onset latency, phone use and sleep duration, PSQI and several sleep parameters, ESS and phone use, and health anxiety with both PSQI and ESS. Weak negative correlations were observed between phone use and computer time, circadian rhythm and both sleep duration and phone use, and between circadian rhythm and PSQI and ESS. There was a moderate positive association observed between the ESS and PSQI scores.Conclusion: The findings suggest that lifestyle changes associated with online education may be linked to alterations in students’ circadian rhythm, sleep quality, and health anxiety. However, most associations were weak, indicating that these outcomes are likely influenced by multiple interacting factors.

Late Chronotype Is Associated With Dizziness and Postural Instability.

OBJECTIVES Sleep has been reported to be associated with dizziness. However, its relationship with chronotype, a behavioral manifestation of circadian rhythms reflecting individual variation in sleep-activity timing, has not been widely investigated. This study aimed to examine the association between chronotype and dizziness and its related symptom profiles. METHODS From the eighth Korea National Health and Nutrition Examination Survey (2021), 3766 participants with information on demographics, underlying diseases, dizziness, and sleep pattern were included after excluding 19 individuals with outlier sleep debt-corrected midpoint of sleep on work-free days (MSFsc) values. Then the subjects were classified into early sleep (MSFsc ≤ 01:00), intermediate sleep (01:00 < MSFsc < 04:30), and late sleep groups (MSFsc ≥ 04:30). RESULTS In the multivariable analysis, the late sleep group had significantly higher prevalence of recurrent dizziness (aOR = 1.480, 95% CI = 1.139-1.922, p = 0.003), postural instability (aOR = 2.354, 95% CI = 1.039-5.332, p = 0.040), and chronic dizziness (aOR = 2.300, 95% CI = 1.449-3.651, p < 0.001) than the intermediate sleep group. Furthermore, the late sleep group exhibited higher prevalence of recurrent dizziness (aOR = 1.464, 95% CI = 1.039-2.062, p = 0.030) and chronic dizziness (aOR = 2.100, 95% CI = 1.173-3.758, p = 0.012) compared with the early sleep group. CONCLUSION Late sleep was significantly associated with dizziness, particularly recurrent dizziness, chronic dizziness, and postural instability, suggesting a potential link with persistent dizziness. Further studies are needed to clarify causality and therapeutic implications. LEVEL OF EVIDENCE: 3

Interaction of genetic risk score and fatty acids quality index on circadian rhythm and quality of life among overweight and obese women

Adolescent circadian sleep health: a review of multimodal assessment strategies and clinical implications

The adolescent developmental period is marked by increased social and academic demands, as well as biological changes that lead to profound shifts in sleep and circadian timing. Circadian misalignment, short sleep duration, and irregular sleep patterns are prevalent among adolescents and are linked to a wide range of negative outcomes, including impaired emotional regulation, diminished academic performance, and increased cardiometabolic disease risk. While efforts to promote adolescent sleep health have grown, the multidimensional nature of circadian sleep health remains underassessed in both research and clinical contexts. This review provides conceptual definitions of key circadian sleep health concepts, synthesizing current best practices for measuring circadian sleep health in adolescents across self-report, behavioral, and physiological domains. We organize assessment strategies around three key circadian constructs—chronotype, circadian timing, and circadian alignment—and describe validated tools for each. In addition, we explore measurements of contextual factors influencing circadian function, such as light exposure, meal and exercise timing, pubertal status, and genetic predispositions. Throughout this review, we emphasize the value of a multimodal approach that combines subjective experience with objective biological and behavioral data to improve clinical utility and advance the understanding of circadian sleep health. We conclude by outlining directions for future research, including the need for validated, developmentally appropriate tools and the integration of wearable technologies to improve accessibility and clinical utility. By consolidating core concepts and methodological tools, this review aims to assist researchers and clinicians selecting appropriate assessment strategies and tailoring interventions to improve adolescent circadian sleep health.