Aging, Nitrate, Endothelial Function and Muscle Oxygenation

Effect of a Beetroot-based Nutritional Gel on Vascular Function and Forearm Muscle Oxygenation Responses in the Elderly at Cardiometabolic Risk

Aging has been associated with reduced bioavailability of nitric oxide (NO) and endothelial dysfunction. Beetroot consumption, a nitrate-rich food, has been associated with increased NO bioconversion, which may promote beneficial effects on vascular health. The present study evaluated the effects of a beetroot-based nutritional gel (BG) on vascular function, arterial stiffness and blood pressure in the elderly at cardiometabolic risk. Twenty elderly individuals were submitted to BG and nitrate-depleted gel (PLA) interventions. Brachial flow-mediated dilation (FMD), blood flow velocity (BFV), peak wave velocity (PWVβ), augmentation index (AI), stiffness parameter (β), pressure-strain elasticity modulus (Ep), arterial compliance (AC), muscle oxygenation and function were measured 90 min after interventions. Urinary nitrate, nitrite, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured at baseline, 90 min and 150 min after interventions.

Study Overview

• Status: Completed
• Conditions: Hypertension; Dyslipidemia; Aging; Abdominal Obesity
• Intervention / Treatment: Other: Beetroot-based nutritional gel; Other: Placebo

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years to 80 years (Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Elderly participants (≥ 65 years)
• Taking between 1 and 3 anti-hypertensive medications for high blood pressure;
• Elevated triglycerides ≥ 150 mg/dL;
• Reduced HDL-cholesterol < 50 mg/dL for women and < 40 mg/dL for men;
• Elevated waist circumference by population definition (male: > 102 cm and female: > 88 cm).

Exclusion Criteria: elevated fasting glucose (≥ 100 mg/dL), smoking, beetroot allergy, unwillingness to avoid beetroot products during the entire study, other chronic diseases (diabetes, liver disease, etc.), or acutely ill.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Beetroot gel (dietary nitrate); Beetroot-based nutritional gel containing approximately 10.0 mmol of nitrate per dose	Other: Beetroot-based nutritional gel; 100 g of beetroot-based nutritional gel containing approximately 12 mmol of nitrate.
Active Comparator: Placebo gel (nitrate-depleted); Nutritional gel nitrate-depleted	Other: Placebo; 100 g of apple-based nutritional gel containing approximately 0.02 mmol of nitrate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Changes in endothelial function as evaluated by the flow-mediated dilation.	Evaluated 120 min after the nutritional intervention
Changes in the arterial stiffness as evaluated by the peak wave velocity.	Evaluated 120 min after the nutritional intervention
Changes in the clinical blood pressure	Evaluated before, 120 min and 180 min after the nutritional intervention
Changes in the muscle oxygenation as evaluated by the levels of oxygenated	Evaluated 150 min after the nutritional intervention
Changes in the muscle function as evaluated by the maximal voluntary contraction of the forearm muscle	Evaluated before and 180 min after the nutritional intervention
Changes in endothelial function as evaluated by blood flow velocity	Evaluated 120 min after the nutritional intervention
Changes in endothelial function as evaluated by reactive hyperemia.	Evaluated 120 min after the nutritional intervention
Changes in the arterial stiffness as evaluated by augmentation index	Evaluated 120 min after the nutritional intervention
Changes in the arterial stiffness as evaluated by the stiffness parameter	Evaluated 120 min after the nutritional intervention
Changes in the arterial stiffness as evaluated by the pressure-strain elasticity modulus	Evaluated 120 min after the nutritional intervention
Changes in the arterial stiffness as evaluated by the arterial compliance.	Evaluated 120 min after the nutritional intervention
Changes in the muscle oxygenation as evaluated by the levels of deoxygenated hemoglobin	Evaluated 150 min after the nutritional intervention

Collaborators and Investigators

• Sponsor: Universidade Federal do Rio de Janeiro
• Collaborators: Rio de Janeiro State Research Supporting Foundation (FAPERJ)

Study record dates

Study Major Dates

• Study Start: May 1, 2015
• Primary Completion (Actual): November 1, 2015
• Study Completion (Actual): January 1, 2016

Study Registration Dates

• First Submitted: May 2, 2016
• First Submitted That Met QC Criteria: May 11, 2016
• First Posted (Estimate): May 16, 2016

Study Record Updates

• Last Update Posted (Estimate): May 17, 2016
• Last Update Submitted That Met QC Criteria: May 15, 2016
• Last Verified: May 1, 2016

More Information

Terms related to this study

• Keywords: Aging; Vascular Function; Functional Food; Beetroot; Dietary Nitrate
• Additional Relevant MeSH Terms: Metabolic Diseases; Overnutrition; Nutrition Disorders; Lipid Metabolism Disorders; Obesity; Dyslipidemias; Obesity, Abdominal
• Other Study ID Numbers: 15510313.5.0000.5257