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Tundra lists 8 Circadian Rhythm Disorders clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.
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NCT07438912
Mind After Midnight
This study examines whether wakefulness during the biological night (2:00-4:00 AM) is associated with increased negative mood, impaired decision-making, and suicidal thoughts. Adults with a history of suicidal ideation in the past six months will complete laboratory and home-based assessments under varying levels of sleep pressure. Participants will be evaluated during late-night wakefulness and under conditions of both higher and lower sleep pressure. The goal of the study is to better understand the biological and behavioral mechanisms that may contribute to elevated suicide risk during nocturnal wakefulness.
Gender: All
Ages: 18 Years - 55 Years
Updated: 2026-05-22
1 state
NCT05619133
PBM Effects on Health and Well-being in Humans
The goal of this clinical study is to assess the effects of different photobiomodulation (PBM) conditions in men and women between 25 and 65 years old with daytime sleepiness/drowsiness and /or mild mood complaints but be otherwise healthy. The main question it aims to answer are: 1. Does PBM significantly affect health and well-being? 2. Are PBM effects wavelength dependent? 3. Are PBM effects pulse dependent? 4. Are the eyes needed to assert an PBM effect or is exposure only to the skin sufficient? 5. What are the cellular, metabolic pathways underlying the systemic effects of PBM. Participants will have to: 1. Exposed themselves 5 times per week during 2 weeks to the PBM stimuli between 9:30 and 12:30. 2. A week before the baseline measurement, participants will have to start wearing a Fitbit Versa 3, and will have to continuously wear until the end of the study. 3. In the afternoon of the baseline day as well as in the afternoons after 5 and 10 PBM sessions (week 1 and week 2, respectively), participants will have to go to the lab for blood withdraw. 4. In the evening of the baseline day as well as in the evenings after 5 and 10 PBM sessions (week 1 and week 2, respectively), participants will have to collect saliva samples as well as to complete questionnaires. It will be a double-blind placebo-controlled field study with a between subject comparison.
Gender: All
Ages: 25 Years - 65 Years
Updated: 2026-04-30
NCT04578249
Effects of Blocking Blue Light at Night Post CABG, AVR, MVR, CABG AVR, CABG MVR, or SAH
Purpose The purpose of this study is to determine whether filtering out blue light at nighttime reduces post-surgical inflammation and/or moderates cognitive decline and mood and sleep alterations in patients undergoing elective CABG, AVR, MVR, CABG AVR, CABG MVR, or SAH surgery. If manipulating nighttime light in hospital rooms improves patient outcomes, then it would be a relatively easy and inexpensive innovation that could reduce post-surgical complications and save millions of dollars per year in health care costs by shortening the length of hospital stays and reducing morbidity. The investigators aim to determine the relationship between inflammation and cognitive dysfunction after cardiac surgery.
Gender: All
Ages: 45 Years - 75 Years
Updated: 2026-04-20
1 state
NCT07440147
Effects of Akkermansia Muciniphila and Berberine Supplementation on Insulin Sensitivity in Night-shift Workers
Night shift work is associated with an increased risk of obesity, insulin resistance, and cardiometabolic disorders, largely due to circadian misalignment, disrupted sleep, and altered eating patterns. These behavioral and physiological disturbances impair glucose metabolism and are further influenced by the gut microbiota. In particular, the bacterium Akkermansia muciniphila has been linked to improved metabolic health, including enhanced insulin sensitivity, lipid regulation, and maintenance of intestinal barrier integrity. Berberine, a bioactive plant-derived compound, has demonstrated metabolic benefits, including upregulation of A. muciniphila, improvement of insulin sensitivity, and modulation of lipid metabolism. Together, these complementary mechanisms suggest that combined A. muciniphila supplementation and berberine administration may synergistically improve metabolic health in shift workers by targeting gut microbiota composition and circadian-regulated metabolic pathways. Based on this rationale, a double-blind, randomized, placebo-controlled, crossover study is being conducted in 200 night-shift workers from healthcare and industrial sectors in Austria and Denmark. Participants are stratified by age, sex, and work sector and randomly assigned to intervention sequences. Each participant receives either the combined supplement or placebo for 12 weeks, followed by a four-week washout, after which the alternate intervention is administered for another 12 weeks, with a total participation of 28 weeks. Assessments are performed at four study visits and include anthropometry, body composition, blood pressure, and collection of blood, urine, and feces. Participants complete validated questionnaires on dietary intake, lifestyle, work schedules, and general health to monitor behavioral patterns throughout the study. Dietary intake is recorded for four days prior to each sampling visit in consideration of shift schedules. Sleep duration and quality are monitored via diaries and actigraphy and aligned with dietary records. Circadian variation is minimized by standardizing sampling times and implementing a fasting and synchronization period prior to visits. The primary outcome is insulin sensitivity, measured by HOMA-IR. Secondary exploratory outcomes include gut microbiota composition and diversity, biomarkers of intestinal permeability and inflammation, lipid profiles, body composition, sleep quality, and dietary behavior. These measures collectively provide a comprehensive evaluation of the metabolic, microbiome, and circadian effects of combined A. muciniphila and berberine supplementation in night-shift workers.
Gender: All
Ages: 21 Years - Any
Updated: 2026-02-27
1 state
NCT06727448
Translation and Validation of the French Version of the Sleep Regularity Questionnaire: a New Tool to Address the the Challenge of Sleep Health
Sleep is an essential function for physical and mental health. The mismatch between biological rhythms and the social rhythms of individuals is increasingly common in modern societies. This sleep irregularity can have numerous consequences on mental health, cardiometabolic health, the immune system, functioning, and quality of life. To address the public health issue of sleep irregularity, it is important to be able to obtain a valid and reliable measure. The Sleep Regularity Questionnaire (SRQ) by Dzierzewski et al. addresses this issue, but has never been translated into French. The aim of the study is to translate and validate the French version of the Sleep Regularity Questionnaire.
Gender: All
Ages: 18 Years - Any
Updated: 2025-12-10
NCT06288568
Night Shift Work and Biomarkers of Obesity Risk in Hospital and Industry Workers
Shift work is a well-known risk factor for the development of overweight and obesity, which may lead to downstream effects such as increased risk of cardiometabolic diseases and cancer. However, the biological and behavioral mechanisms underlying the obesogenicity of night shift work are not well understood. Population-based mechanistic studies in real life shift workers are needed to address how night shift work impacts metabolic health. The investigators aim to characterize the behavioural, environmental, and biological mechanisms and pathways for the association of night shift work and obesity across Europe. The investigators will conduct a cross sectional study in 5 European countries (Austria, Denmark, Germany, Netherlands and Poland) and recruit 1000 rotating night shift workers and day workers (200/country) from the health sector and different industries. Night and day workers will be age-frequency (3 age groups), gender and (where possible) working tasks matched. Participants will complete online questionnaires and report their diet habits in a mobile app. Body composition, dietary behavior and sensory preferences will be tested. Biologic specimens (blood, urine, saliva, hair and feces) will be collected at the workplace on a day where participants are working on a day shift (or a day off). In a subsample (Austria and Netherlands) shift workers will provide biological samples (spot blood, urine and saliva) both on a day shift and on a night shift. Biomarkers including hormones, cellular immunity and inflammation, parameters linked to gut health and metabolism of fat and sugar, appetite, oxidative stress, metabolomics and microbiota will be measured. The investigators hypothesize that compared to day workers, night shift workers will experience disrupted levels of pre-obesity markers. Higher circadian disruption, sleep disruption and mistimed eating patterns workers will be associated with more disrupted biomarker profiles. Among rotating shift workers, night shift will be associated with acute disrupted melatonin production, metabolomic profiles and composition of oral microbiota compared to a day shift.
Gender: All
Ages: 21 Years - Any
Updated: 2025-09-08
1 state
NCT06951776
Chronotherapeutic Optimization of Teriparatide Administration in Postmenopausal Osteoporosis
This is a randomized, controlled, and exploratory study designed to evaluate the chronotherapeutic effects of teriparatide administration in postmenopausal osteoporosis. Twenty-eight participants (age 60-70 years, lumbar spine T-score ≤-3.0) will undergo 1:1 randomization to receive 20 µg/day teriparatide subcutaneously at either 08:00 or 20:00 for 12 weeks. Standardized supplementation with calcium (1,000-1,500 mg/day) and cholecalciferol (800-1,200 IU/day) will be maintained. Primary endpoints are between-group differences in serum CTX and P1NP profiles, quantified at baseline, 4-week interim, and 12-week endpoint. The secondary outcomes will assess safety during the trial.
Gender: FEMALE
Ages: 60 Years - 70 Years
Updated: 2025-04-30
NCT06129942
Light Therapy in Parkinson's Disease
The aim of this randomized controlled trial (RCT) is to clarify the effect of bright light therapy on motor symptoms and sleep disorders in patients with Parkinson's disease.
Gender: All
Ages: 50 Years - 80 Years
Updated: 2025-02-12
1 state