A Phase 1/2 interventional study of Drug Lowering Cerebral Blood Flow (CBF) and Normoxia Sleep and Drug Lowering CBF and Intermittent Hypoxia Sleep in Obstructive Sleep Apnea of Adult, Hypoxia, Brain and Sleep Apnea, sponsored by University of Calgary. Recruiting at 1 site in Canada. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-01.
Sponsored by University of Calgary · Phase 1/2, Interventional, and Basic science
A prospective double blind, placebo-controlled, randomized cross-over trial to evaluate the effect of lowering cerebral blood flow on the ventilatory chemoreflexes (acute hypoxic and hypercapnic ventilatory responses).
The investigators will explore the relationship between changes in Cerebral Blood Flow (CBF) and ventilatory chemoreflexes i.e. Acute Ventilatory Response to Hypoxia (AHVR) and Acute Hypercapnic Ventilatory Response (HCVR) before, during and after sleep under normoxic conditions and sleep accompanied by isocapnic Intermittent Hypoxia (IH) among healthy human study participants.
A pharmacological intervention will be utilized to manipulate the CBF in a randomized order. The study participants will also be randomly assigned the order to sleep either under normoxia or IH exposure. The experiments will be separated from one another with an interval of sufficient drug and IH exposure washout period. The venous blood samples and urinary samples will be collected for the vascular biomarkers.
Exclusion Criteria:
Study participants will take drug lowering Cerebral Blood Flow (CBF) and sleep under room air i.e. normoxia exposure.
Drug: Drug Lowering Cerebral Blood Flow (CBF) and Normoxia Sleep
Study participants will take drug lowering Cerebral Blood Flow (CBF) and sleep under Intermittent Hypoxia (IH) exposure.
Drug: Drug Lowering CBF and Intermittent Hypoxia Sleep
Study participants will take Placebo that has no effect on Cerebral Blood Flow (CBF) and sleep under room air i.e. normoxia exposure.
Drug: Placebo and Normoxia Sleep
Study participants will take Placebo that has no effect on Cerebral Blood Flow (CBF) and sleep under Intermittent Hypoxia (IH) exposure.
Drug: Placebo and Intermittent Hypoxia Sleep
The study participants will take Cerebral Blood Flow (CBF) lowering drug and sleep under Normoxia Exposure
Also known as: Cerebral Blood Flow changes and Normoxia Sleep
The study participants will take Cerebral Blood Flow (CBF) lowering drug and sleep under Intermittent Hypoxia (IH) Exposure
Also known as: CBF changes and Intermittent Hypoxia Sleep
The study participants will take Placebo and sleep under Normoxia Exposure
Also known as: Cerebral Blood Flow (CBF) with Placebo in Normoxia Sleep
The study participants will take Placebo and sleep under Intermittent Hypoxia (IH) Exposure
Also known as: CBF with Placebo in Intermittent Hypoxia Sleep
Changes in cerebral blood flow and ventilatory chemoreflexes
The relationship between changes in cerebral blood flow (CBF) and ventilatory chemoreflexes (acute hypoxic and hypercapnic ventilatory responses) before and after sleeping under normoxia and intermittent hypoxia exposure among healthy human study participants.
Time frame: ~18 months (from the starting time of recruiting study participants)
Cerebral blood flow responses and ventilatory chemoreflexes during sleep
The relationship between cerebral blood flow (CBF) changes and ventilatory chemoreflexes (acute hypoxic and hypercapnic ventilatory responses) during sleep under normoxia and intermittent hypoxia exposure among healthy human study participants.
Time frame: ~18 months (from the starting time of recruiting study participants)
Changes in reactive oxygen species and vascular biomarkers
The changes in vascular biomarkers such as nitric oxide, reactive oxygen species and exosome analysis or urinary prostaglandins before and after sleep under normoxia and intermittent hypoxia exposure with cerebral blood flow changes.
Time frame: ~24 months (from the starting time of recruiting study participants)
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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University of Calgary