Inorganic Nitrate and OSA

University of Iowa

Status: Completed

Conditions: Obstructive Sleep Apnea

Treatments: Dietary Supplement: Post-beetroot juice supplementation; Dietary Supplement: Pre-beetroot juice supplementation

Study type: Interventional

Funder types: Other

Identifiers

NCT03930563

201812786

Details and patient eligibility

About

The main purpose of this study is to determine if acute beetroot juice supplementation reduces peripheral chemoreflex sensitivity in patients with obstructive sleep apnea. All subjects will consume low-dose (BRL), higher-dose (BRH), and placebo (BRP) beetroot juice randomly on three independent study visits. Beetroot juice also improves blood flow thus, the investigators will also measure blood flow to the carotid chemoreceptors.

Full description

Four-weeks of daily beetroot juice supplementation reduces peripheral chemoreflex sensitivity in healthy older adults who have 'normal' responses to acute hypoxia. Patients with obstructive sleep apnea have exaggerated peripheral chemoreflex sensitivity. It remains unknown if beetroot juice supplementation reduces peripheral chemoreflex sensitivity in patients with obstructive sleep apnea. Additionally, increasing blood flow to the peripheral chemoreceptors reduces sensitivity. Given that beetroot juice improves blood flow, the investigators will also measure common carotid artery blood flow at rest and during hypoxia.

Enrollment: 21 patients

Sex: All

Ages: 30 to 70 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• OSA group: patients recently diagnosed with mild-to-moderate OSA
• Control group: healthy individuals

Exclusion criteria

• Diagnosis of heart disease
• Diagnosis of diabetes
• Diagnosis of any autonomic disorders
• Diagnosis of kidney disease
• Diagnosis of central sleep apnea
• Regular physical activity exceeding 30 minutes 3 days/week
• A body mass index ≥40 kg/m2
• Current or former use of a continuous positive airway pressure machine
• Current tobacco use
• Currently prescribed hormone replacement therapy

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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21 participants in 3 patient groups

Beetroot Juice Low

Experimental group

Description:

Subjects will consume beetroot juice containing 250mg inorganic nitrate and 20mg nitrite dissolved in 120ml bottled water. Peripheral chemoreflex sensitivity as well as common carotid artery blood flow will be assessed before and after supplementation.

Treatment:

Dietary Supplement: Pre-beetroot juice supplementation

Dietary Supplement: Post-beetroot juice supplementation

Beetroot Juice High

Experimental group

Description:

Subjects will consume beetroot juice containing 500mg inorganic nitrate and 40mg nitrite dissolved in 120ml bottled water. Peripheral chemoreflex sensitivity as well as common carotid artery blood flow will be assessed before and after supplementation.

Treatment:

Dietary Supplement: Pre-beetroot juice supplementation

Dietary Supplement: Post-beetroot juice supplementation

Beetroot Juice Placebo

Active Comparator group

Description:

Subjects will consume beetroot juice devoid of inorganic nitrate and nitrite dissolved in 120ml bottled water. Peripheral chemoreflex sensitivity as well as common carotid artery blood flow will be assessed before and after supplementation.

Treatment:

Dietary Supplement: Pre-beetroot juice supplementation

Dietary Supplement: Post-beetroot juice supplementation