How changes in brain blood flow affect breathing during sleep
Role of Cerebral Blood Flow on Ventilatory Stability During Sleep in Normoxia and Intermittent Hypoxia
PHASE1; PHASE2 · University of Calgary · NCT03255408
This project will test whether temporarily lowering blood flow to the brain changes how healthy adults' breathing responds to low oxygen and high carbon dioxide during normal sleep and short periods of low oxygen.
Quick facts
| Phase | PHASE1; PHASE2 |
|---|---|
| Study type | Interventional |
| Enrollment | 12 (estimated) |
| Ages | 18 Years to 45 Years |
| Sex | All |
| Sponsor | University of Calgary (other) |
| Locations | 1 site (Calgary, Alberta) |
| Trial ID | NCT03255408 on ClinicalTrials.gov |
What this trial studies
This randomized, double-blind, placebo-controlled crossover study uses a drug to lower cerebral blood flow and compares ventilatory chemoreflexes before, during, and after sleep under normal oxygen and isocapnic intermittent hypoxia. Participants will sleep under both conditions in random order with washout periods between sessions while investigators measure acute ventilatory responses to hypoxia (AHVR) and hypercapnia (HCVR). Cerebral blood flow will be pharmacologically manipulated in randomized order against placebo, and venous blood and urine samples will be collected for vascular biomarkers. All procedures are performed at a single center (University of Calgary) in healthy adults aged 18–45.
Who should consider this trial
Good fit: Healthy adults aged 18–45 living in Calgary for at least one year who are non-smokers, not pregnant or obese, free of major cardiovascular, cerebrovascular, renal, or metabolic disease, not taking blood pressure medications, and not lactose intolerant.
Not a fit: People with obstructive sleep apnea, obesity, pregnancy, smoking history, major chronic diseases, or those taking blood pressure medications are excluded and unlikely to receive direct benefit from participation.
Why it matters
Potential benefit: If successful, findings could clarify how brain blood flow influences breathing control during sleep and guide strategies to protect breathing in people at risk for sleep-disordered breathing or cerebrovascular events.
How similar studies have performed: Prior physiological studies have examined cerebral blood flow and ventilatory chemoreflexes in short-term settings, but combining pharmacological CBF lowering with isocapnic intermittent hypoxia during sleep is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Healthy adults * 18 - 45 years of age * Living in Calgary for the past one year * Have no medical condition or should not be taking any blood pressure medications. * The participant should not be lactose intolerant Exclusion Criteria: * Cerebrovascular, cardio-respiratory, renal and metabolic diseases * Bleeding disorders and upper gastrointestinal diseases e.g. peptic ulcer disease * Pregnancy, obese and sleep-disordered breathing * Drug allergies to non-steroidal anti-inflammatories * Currently smoking
Where this trial is running
Calgary, Alberta
- University of Calgary — Calgary, Alberta, Canada (RECRUITING)
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Obstructive Sleep Apnea of Adult, Hypoxia, Brain, Sleep Apnea, Sleep Disorder, Stroke, Blood Pressure, Endothelial Dysfunction, Oxidative Stress