Exercise and Vascular Function in Postmenopausal Females With Hypertension

Study Overview
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Brief Summary
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The treatment of high blood pressure, or hypertension, is multifaceted and can include pharmacological therapies (i.e., medications) and lifestyle modifications such as physical activity. Chronotherapy, which describes timing of a treatment with the body's daily rhythms, has recently been used with hypertension medications and has been shown to be effective at lowering blood pressure and reducing the risk of cardiovascular disease events. Specifically, taking medications in the evening was shown to be more effective than morning medication routines. Little information is available about the effectiveness of chronotherapy combined with exercise (i.e., planned physical activity) interventions in older adults with hypertension. The purpose of this study is to examine how exercise performed in the morning and early evening affects blood pressure and other measures of blood vessel health in postmenopausal females with hypertension.

Detailed Description
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Blood pressure has an internal rhythm associated with the 24-hr clock. Nocturnal blood pressure (BP) is a key contributor to cardiovascular health and may be improved by exercise. Moreover, the time of day of the exercise may be a key factor. This study aims to evaluate the effect of evening exercise on BP and other measures of vascular function in older females with hypertension.

Official Title
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The Effects of Exercise Time of Day on Blood Pressure and Vascular Function

Conditions
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Hypertension

Intervention / Treatment
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* Behavioral: Exercise
* Behavioral: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Systolic BP equal to or greater than 130 mmHg without BP medication or greater than 120 mmHg with medication and diastolic blood pressure equal to and greater than 80 mmHg 55-80 years old Post-menopausal female Early or intermediate chronotype Able to walk without assistance Exclusion Criteria: Habitually physically active defined as 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic physical activity per week Overt pulmonary disease/condition as follows: chronic bronchitis, chronic obstructive pulmonary disease, emphysema, or pulmonary hypertension Cardiometabolic disease/condition as follows: diabetes, heart failure, peripheral arterial disease, stroke, coronary artery disease, renal disease, secondary hypertension, chronic venous insufficiency or deep vein thrombosis within last 6 months Cancer within last 5 years Body mass index >39 kg/m2 Current smoking or vape Evening shift work

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Morning (AM)<br>Before 10 A.M. | Behavioral: Exercise<br>* walking and handgrip exercise<br>Behavioral: Control<br>* seated rest<br>|
| Experimental: Evening (PM)<br>After 4 P.M. | Behavioral: Exercise<br>* walking and handgrip exercise<br>Behavioral: Control<br>* seated rest<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nocturnal systolic blood pressure (BP) | Reduction in systolic nocturnal BP (exercise-control) | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Early post-exercise hypotension | Post-exercise systolic BP (exercise - control) | 30 minutes | 
| Endothelial function | Flow mediated dilation of the brachial artery | 24 hours | 
| Microvascular function | Rapid onset vasodilation of the popliteal artery | 24 hours |