Exercise Training Intensity and Nitrate Supplementation in Post-Menopausal Females

University of Virginia40 enrolled

Overview

Menopause greatly increases cardiovascular disease risk (CVD). Current exercise guidelines are inadequate to ameliorate this risk and higher intensity exercise may be necessary for cardiovascular benefits in postmenopausal females. Oral nitrate supplementation enhances exercise performance and CVD risk profile in several clinical conditions. The investigators recently reported that 3-days of nitrate supplementation in postmenopausal females enhances acute post-exercise vascular function, in an intensity dependent manner. The effects of nitrate supplementation and exercise training over a longer training program remains unexplored. This investigation will examine the impact of exercise training intensity with and without inorganic nitrate supplementation, on CVD and fitness outcomes. Postmenopausal females will be tested for maximal oxygen uptake and lactate threshold before randomization to one of four groups: that inorganic nitrate-rich beetroot juice, or beetroot juice with nitrate extracted; and assigned to one-month of calorie matched high-intensity or moderate-intensity exercise training. Vascular function and fitness will be evaluated before and after training.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

QUADRUPLE

Enrollment

Conditions

Menopause

Interventions

Eligibility

Sex: FEMALEMin age: 45 YearsMax age: 75 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Post-menopausal female (greater than age 45 but less than age 75) * Sedentary (does not exercise regularly or less than 2 bouts of exercise per week) * No major changes in medication in the last 3 months Exclusion Criteria: * Smokers within last 5 years * Weight unstable (loss/gain of more than 3kg in the past 3 months) * Any medical condition that prevents the subject from exercising safely * Hormone replacement therapy (current or within last 3 months) * Diabetes * Currently or recently on vasoactive medications (i.e., calcium channel blockers, statins, ACE or renin inhibitors, ARBs, nitrates, alpha- or beta-blockers, diuretics, proton pump inhibitors, etc.) * Oral antibiotic use within previous four weeks * Oral disease or poor oral health as determined by the Oral Health Questionnaire * Using an antibacterial mouthwash or a mouthwash containing chlorhexidine and unwilling to discontinue use

Outcomes

Primary Outcomes

Vascular Endothelial Function (Flow-Mediated Dilation [FMD])

Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The arteries will be imaged using a high-resolution 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 3 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle.