Recruiting
Phase 1
Phase 2

Cerebral Blood Flow

Sponsor:

University of Calgary

Code:

NCT03255408

Conditions

Obstructive Sleep Apnea of Adult

Hypoxia, Brain

Sleep Apnea

Sleep Disorder

Stroke

Eligibility Criteria

Sex: All

Age: 18 - 45

Healthy Volunteers: Accepted

Interventions

Drug Lowering Cerebral Blood Flow (CBF) and Normoxia Sleep

Drug Lowering CBF and Intermittent Hypoxia Sleep

Placebo and Normoxia Sleep

Placebo and Intermittent Hypoxia Sleep

Study Details

Brief summary:

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).

Conditions

Obstructive Sleep Apnea of Adult

Hypoxia, Brain

Sleep Apnea

Sleep Disorder

Stroke

Study ID

NCT03255408

Start date

Jan 1, 2023

Status verified date

Apr, 2026

Completion date

Dec 30, 2027

Anticipated

Primary completion date

Dec 30, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 45

Healthy Volunteers: Accepted

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

Study Design

Enrollment

12 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

active comparator: CBF Lowering and Normoxia Sleep

Study participants will take drug lowering Cerebral Blood Flow (CBF) and sleep under room air i.e. normoxia exposure.

experimental: CBF Lowering and IH Sleep

Study participants will take drug lowering Cerebral Blood Flow (CBF) and sleep under Intermittent Hypoxia (IH) exposure.

sham comparator: Placebo and Normoxia Sleep

Study participants will take Placebo that has no effect on Cerebral Blood Flow (CBF) and sleep under room air i.e. normoxia exposure.

placebo comparator: Placebo and IH Sleep

Study participants will take Placebo that has no effect on Cerebral Blood Flow (CBF) and sleep under Intermittent Hypoxia (IH) exposure.

Interventions

Drug Lowering Cerebral Blood Flow (CBF) and Normoxia Sleep

The study participants will take Cerebral Blood Flow (CBF) lowering drug and sleep under Normoxia Exposure

Drug Lowering CBF and Intermittent Hypoxia Sleep

The study participants will take Cerebral Blood Flow (CBF) lowering drug and sleep under Intermittent Hypoxia (IH) Exposure

Placebo and Normoxia Sleep

The study participants will take Placebo and sleep under Normoxia Exposure

Placebo and Intermittent Hypoxia Sleep

The study participants will take Placebo and sleep under Intermittent Hypoxia (IH) Exposure

Primary outcome measure

  • Changes in cerebral blood flow and ventilatory chemoreflexes [ Time Frame: ~18 months (from the starting time of recruiting study participants) ]
  • Cerebral blood flow responses and ventilatory chemoreflexes during sleep [ Time Frame: ~18 months (from the starting time of recruiting study participants) ]

Central Contacts and Locations

Locations

University of Calgary

Recruiting

Calgary, Alberta, Canada, T2N 4N1

Contacts

Chair, Conjoint Ethics Board

chreb@ucalgary.ca

More Information

Sponsor

University of Calgary

Last update posted

May 1, 2026

Last verified

Apr, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Calgary on 2026-05-01.