Isometric Handgrip Exercise for Blood Pressure Management

Study Overview
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Brief Summary
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Recent meta-analyses suggest isometric resistance training (IRT) may be superior to aerobic exercise for lowering blood pressure. The investigators intend to conduct the largest, longest, prospective, double-blind randomized controlled trial using isometric resistance training to reduce blood pressure to reduce hypertension.

Detailed Description
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We are looking to assess the effect of isometric exercise on ambulatory blood pressure in participants aged 40-70 years who are either pre- or mild hypertensive; either un-medicated or taking medication to control their blood pressure. Our secondary aims are to examine whether the size of blood pressure change is different in those people taking or not taking anti-hypertensive medication, to determine the anti-hypertensive mechanism to IRT, and to establish rate of de-training effects after participants have ceased IRT.

Official Title
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Cardiovascular Response to Isometric Resistance Training in People With Hypertension for Blood Pressure Management

Conditions
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Hypertension

Intervention / Treatment
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* Other: Isometric resistance training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Blood pressure above 120/80 currently not taking anti-hypertensive medications whose doctor has suggested would benefit from exercise; and people currently taking beta blockers for blood pressure management. Exclusion Criteria: Younger than 30yrs and older than 70 yrs; unable to voluntary participate; unable to participate under doctor's recommendation; smokers; arthritis or carpal tunnel which may be aggravated with handgrip exercise; known cardiovascular disease (angina) and the following co-morbid conditions: obesity, insulin resistance, depression, mobility impairment, sleep apnoea, fatty liver disease or renal disease

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: IHG 5% Un-medicated<br>Participants with high blood pressure (greater than 120/80) who are not medicated for blood pressure control will conduct isometric handgrip (IHG) exercise at 5% of their maximum voluntary contraction (MVC). Isometric resistance training will be conducted three times a week for 12 weeks, with participants conducting 4 x 2min IHG exercises at each session. | Other: Isometric resistance training<br>* Isometric handgrip exercise using a hand dynamometer<br>|
| Sham Comparator: IHG 5% BB<br>Participants with high blood pressure (greater than 120/80) who are currently taking beta blockers for blood pressure control will conduct isometric handgrip exercise at 5% of their maximum voluntary contraction (MVC). Isometric resistance training will be conducted three times a week for 12 weeks, with participants conducting 4 x 2min IHG exercises at each session. | Other: Isometric resistance training<br>* Isometric handgrip exercise using a hand dynamometer<br>|
| Experimental: IHG 30% Un-medicated<br>Participants with high blood pressure (greater than 120/80) who are not medicated for blood pressure control will conduct isometric handgrip exercise at 30% of their maximum voluntary contraction (MVC). Isometric resistance training will be conducted three times a week for 12 weeks, with participants conducting 4 x 2min IHG exercises at each session. | Other: Isometric resistance training<br>* Isometric handgrip exercise using a hand dynamometer<br>|
| Experimental: IHG 30% BB<br>Participants with high blood pressure (greater than 120/80) who are currently taking beta blockers for blood pressure control will conduct isometric handgrip exercise at 30% of their maximum voluntary contraction (MVC). Isometric resistance training will be conducted three times a week for 12 weeks, with participants conducting 4 x 2min IHG exercises at each session. | Other: Isometric resistance training<br>* Isometric handgrip exercise using a hand dynamometer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in systolic and diastolic blood pressure |  | Change measures: baseline and 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare and contrast change in systolic and diastolic blood pressure of medicated and un-medicated participants |  | Baseline and 12 weeks | 
| Detraining effects, changes in systolic and diastolic blood pressure after cessation of Isometric Resistance Training | End of exercise protocol and 12 weeks after completion | 12 weeks and 24 weeks |