Postmenopausal Women and Their Endothelium

Penn State University37 enrolled

Overview

The purpose of this study is to test the effects of a one time dose and 7-days of inorganic nitrate (supplied in the form of beetroot juice) on blood vessel function and resting blood pressure in healthy, postmenopausal women. Participants will drink beetroot juice and a placebo juice on separate visits where blood pressure and blood vessel function will be measured.

Cardiovascular disease is the leading cause of death in the United States. Due to the loss of estrogen, women experience a unique accelerated rise in cardiovascular disease risk factors following menopause. Postmenopausal women represent a population at heightened risk for cardiovascular disease development. Function of the endothelium has been shown to decline across the menopause transition, resulting in less production of nitric oxide. As such the investigators are investigating a potential therapeutic strategy in women have recently undergone menopause to boost nitric oxide availability.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Enrollment

Conditions

Postmenopausal Women

Interventions

nitrate rich beetroot juiceDRUG

This beverage contains 0.3 g of inorganic nitrate per 70 ml container, and is bottled and supplied by James White Drinks (UK).

nitrate depleted beetroot juiceDRUG

This beverage is identical in look and taste to the Beet-It organic shot, but has the nitrate removed. It is also bottled and supplied by James White Drinks (UK).

Eligibility

Sex: FEMALEMax age: 70 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Early post-menopausal women who are within 1-6 years following their final menstrual cycle * Late post-menopausal women who are beyond 6 years following their final menstrual cycle Exclusion Criteria: * Individuals with any overt cardiovascular, metabolic, hematologic, pulmonary, renal, musculoskeletal, and/or neurological disease(s). * Users of any tobacco and/or nicotine products (smokers, chewing tobacco, nicotine-containing patches/gum, smokeless cigarettes) * Individuals with a BMI \> 35 * Individuals with resting blood pressure \> or = 130/80 mm Hg * Individuals with high blood lipids (total cholesterol \> or = 240 mg/dl, LDL \> or = 160 mg/dl, triglycerides \> or = 200 mg/dl). * Postmenopausal women with hyperglycemia (fasting glucose \> or = 110 mg/dl and HbA1c \>6.0%). * Individuals taking any of the following medications: 1. blood pressure lowering medication (e.g., beta blockers, ACE inhibitors, angiotensin antagonists, calcium channel blockers, diuretics) 2. lipid- lowering medication (e.g., statins) 3. nitrates (e.g. nitroglycerin) for angina 4. phosphodiesterase inhibitors (e.g., Viagra) 5. anti-Inflammatory drugs * Individuals taking hormone therapy

Locations (1)

Penn State University

University Park, Pennsylvania, United States

Outcomes

Primary Outcomes

Macro-vascular reactivity

Using near-infrared spectroscopy, a probe placed on the forearm muscle will be used to measure the tissue saturation index re-perfusion slope following 5 minutes of forearm cuff occlusion.

Time frame: These measurements will take place before and after a ischemia-reperfusion injury (20 minutes inflation, 20 minutes deflation) induced in the upper arm to assess change in macro-vascular reactivity

Micro-vascular reactivity

Using near-infrared spectroscopy, a probe placed on the forearm muscle will be used to measure area under the curve for tissue saturation index re-perfusion following 5 minutes of forearm cuff occlusion.

Secondary Outcomes

Resting blood pressures

Resting systolic blood pressures will be measured in the arm (cuff) and estimated in the aorta (radial artery tonometry).

Time frame: Change from baseline resting blood pressure and at 90 minutes after beet root juice ingestion

Recovery of micro-vascular function and brachial artery flow mediated dilation

Micro-vascular and brachial artery flow-mediated dilation, as described above, will be reassessed 30 minutes following ischemia-reperfusion injury to determine recovery of vessel function.

Time frame: Change in these measures from immediately after ischemia-reperfusion injury to 30 minutes following

Brachial artery flow-mediated dilation

Using doppler ultrasound the brachial artery diameter will be measured before and after 5 minutes of forearm cuff occlusion

Data from ClinicalTrials.gov

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