Cerebral Blood Flow and Ventilatory Responses During Sleep in Normoxia and Intermittent Hypoxia

University of Calgary

Status and phase: Not yet enrolling; Phase 2; Phase 1

Conditions: Obstructive Sleep Apnea of Adult; Endothelial Dysfunction; Stroke; Sleep Disorder; Oxidative Stress; Sleep Apnea; Blood Pressure; Hypoxia, Brain

Treatments: Drug: Drug Lowering Cerebral Blood Flow (CBF) and Normoxia Sleep; Drug: Placebo and Normoxia Sleep; Drug: Placebo and Intermittent Hypoxia Sleep; Drug: Drug Lowering CBF and Intermittent Hypoxia Sleep

Study type: Interventional

Funder types: Other

Identifiers

NCT03255408

REB13-0880

Details and patient eligibility

About

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).

Full description

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.

Enrollment: 12 estimated patients

Sex: All

Ages: 18 to 45 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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12 participants in 4 patient groups, including a placebo group

CBF Lowering and Normoxia Sleep

Active Comparator group

Description:

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

Treatment:

Drug: Drug Lowering Cerebral Blood Flow (CBF) and Normoxia Sleep

CBF Lowering and IH Sleep

Experimental group

Description:

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

Treatment:

Drug: Drug Lowering CBF and Intermittent Hypoxia Sleep

Placebo and Normoxia Sleep

Sham Comparator group

Description:

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

Treatment:

Drug: Placebo and Normoxia Sleep

Placebo and IH Sleep

Placebo Comparator group

Description:

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

Treatment:

Drug: Placebo and Intermittent Hypoxia Sleep