Recruiting

Observational Study

Sponsor:

Oregon Health and Science University

Code:

NCT06535178

Conditions

Circadian Rhythm

Cardiometabolic Health

Vascular Health

Pain

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Interventions

Sleep Regularity Group

Study Details

Brief summary:

The goal of this study is to identify the effects of sleep regularity on cardiovascular regulatory mechanisms. The investigators are hoping to discover if improving the regularity of sleep timing will improve metabolic and vascular health markers. The protocol is a 12-week prospective cohort study that includes both field and in-laboratory data collection in ostensibly healthy male and female adults, aged 18-40years. We will also have a sub-group of individuals with chronic pain to examine the effects of sleep regularity on pain outcomes.

Conditions

Circadian Rhythm

Cardiometabolic Health

Vascular Health

Pain

Study ID

NCT06535178

Start date

Jul 1, 2024

Status verified date

Nov, 2025

Completion date

Sep 30, 2026

Anticipated

Primary completion date

Sep 30, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Ostensibly healthy men and women Subgroup study (chronic pain)
  • Satisfies diagnostic criteria for fibromyalgia according to the Widespread Pain Index - Symptom Severity (WPI-SS) scale with the following three conditions being met:

1. Widespread pain index (WPI) ≥7 and symptom severity (SS) scale score ≥5 or WPI 3-6 and SS scale score ≥9.
2. Symptoms have been present at a similar level for at least 3 months.
3. The patient does not have a disorder that would otherwise explain the pain.

Exclusion Criteria:

  • No history of drug or alcohol dependency.
  • Must be current non-smokers, and are required to have a history of less than 5 pack years of smoking.
  • No history of working irregular day and night hours, regular night work, or rotating shift work for the 1 year prior to the study. In addition to this, individuals must not have traveled across more than 1 time zone during the 3 months prior to the study.
  • Chronobiologic and sleep disorders.
  • Diseases of the cardiovascular system.
  • Hypertension. Individuals will be allowed to be normotensive (resting systolic blood pressure of <140/90 mmHg, measured on more than one occasion) or uncomplicated stage 1 hypertension (systolic BP between 140 and 159 mmHg or a diastolic BP between 90 and 99 mmHg).
  • Disorders of the respiratory system.
  • Pre-diabetes/Diabetes. For participants who have self-reported pre-diabetes/diabetes.
  • Disorders of the kidney and urinary tract.
  • Infectious diseases.
  • Disorders of the gastrointestinal system.
  • Disorders of the immune system.
  • Disorders of the hematopoietic system.
  • Neoplastic diseases.
  • Endocrine and metabolic diseases.
  • Neurologic disorders.
  • Must not be participating in another research study that would influence their safe participation in the study.

Study Design

Enrollment

30 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Sleep Regularity Group

Individuals in the lowest SRI tertile will begin the 12-week intervention to improve sleep regularity. Participants will be instructed to maintain a consistent sleep onset time (±30 min self-selected sleep time).

no intervention: Control Group

All other participants will be instructed to maintain their habitual sleep patterns.

Interventions

Sleep Regularity Group

Maintained consistent sleep onset time (±30 min self-selected sleep time) for 12-weeks.

Primary outcome measure

  • Changes in dim-light melatonin onset [ Time Frame: Week 0 and Week 12 ]
  • Changes in SRI [ Time Frame: Week 0 and Week 12 ]
  • Changes in vascular endothelial function [ Time Frame: Week 0 and Week 12 ]
  • Changes in heart rate [ Time Frame: Week 0 and Week 12 ]
  • Changes in blood pressure [ Time Frame: Week 0 and Week 12 ]
  • Changes in resting cardiac vagal tone [ Time Frame: Week 0 and Week 12 ]
  • Changes in heart rate response to exercise [ Time Frame: Week 0 and Week 12 ]
  • Changes in blood pressure response to exercise [ Time Frame: Week 0 and Week 12 ]
  • Changes in energy metabolism [ Time Frame: Week 0 and Week 12 ]
  • Changes in glucose [ Time Frame: Week 0 and Week 12 ]

Central Contacts and Locations

Central contacts

Andrew W McHill, PhD

(503) 494 - 2594mchill@ohsu.edu

Brooke M Shafer

(503) 494 - 0670shaferb@ohsu.edu

Locations

Oregon Health & Science University

Recruiting

Portland, Oregon, United States, 97239

Contacts

Andrew McHill, PhD

(503) 949-2594mchill@ohsu.edu

More Information

Sponsor

Oregon Health and Science University

Last update posted

Nov 10, 2025

Last verified

Nov, 2025

Keywords

  • Circadian Rhythm
  • Cardiometabolic Health
  • Vascular Health
  • Pain

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Oregon Health and Science University on 2025-11-10.