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A 2 Week, Crossover Trial of Dietary Nitrate in Obstructive Sleep Apnoea Syndrome (OSAS).

Not Applicable
Completed
Conditions
Obstructive Sleep Apnoea Syndrome
Interventions
Dietary Supplement: Placebo
Dietary Supplement: Dietary nitrate
Registration Number
NCT02515071
Lead Sponsor
Royal College of Surgeons, Ireland
Brief Summary

Acute consumption of dietary nitrate (as beetroot juice) has been shown to decrease systemic blood pressure in multiple populations as well as increase organ perfusion in areas of interest such as the pancreas and brain. Obstructive sleep apnoea syndrome (OSAS) is associated with high blood pressure, dysglycaemia and impaired vigilance. The effect of dietary nitrate in OSAS has not been reported.

Detailed Description

Acute consumption of dietary nitrate (as beetroot juice) has been shown to decrease systemic blood pressure in multiple populations as well as increase organ perfusion in areas of interest such as the pancreas and brain. Obstructive sleep apnoea syndrome (OSAS) is associated with high blood pressure, dysglycaemia and impaired vigilance. The effect of dietary nitrate in OSAS has not been reported.

The investigators hypothesize that chronic nitrate consumption might decrease blood pressure and dysglycaemia and improve vigilance compared to a placebo beetroot juice.

This study is a randomized, double-blind placebo-controlled, crossover trial. At baseline, mid-point and endpoint ambulatory blood pressure will be assessed in conjunction with demographics, questionnaires, vigilance and blood draw. After baseline measures, each subject will be randomized to consume nitrate rich beetroot juice for 14 consecutive nights when assessments will be repeated followed by 14 nights of placebo and endpoint assessments or the converse.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
10
Inclusion Criteria
  • Clinically stable,
  • Untreated OSAS out-patients
Exclusion Criteria
  • Using continuous positive airways pressure therapy
  • Pulmonary hypertension
  • Active CVD
  • Active musculo-skeletal conditions
  • Taking vasodilators
  • Diabetes mellitus

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Nitrate depleted placebo beetroot juicePlaceboPlacebo beetroot juice is identical to active beetroot juice in every way except nitrate content.
Nitrate rich beetroot juiceDietary nitrateConcentrated, beetroot juice is a rich source of dietary nitrate.
Primary Outcome Measures
NameTimeMethod
Difference in ambulatory nocturnal blood pressureDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Secondary Outcome Measures
NameTimeMethod
Difference in OSAS symptomatologyDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in exhaled nitric oxideDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in 2h post OGT glucoseDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in vigilance scores derived from the Conner's Continuous Performance Test.Day 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in 24h blood pressureDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in plasma nitrate and nitriteDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in fasting glucoseDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Difference in overnight oximetryDay 1, day 15, day 29

Comparison of the change after nitrate-rich beetroot juice compared to placebo.

Trial Locations

Locations (1)

Connolly Hospital, Blanchardstown

🇮🇪

Dublin, Ireland

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