Isometric Resistance Exercise for Hypertension
NCT Number: NCT06510998
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Hypertension
Interventions: BEHAVIORAL: isometric wall exercise|BEHAVIORAL: passive stretching
Sponsor: Chinese University of Hong Kong
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 390
Study Design: Allocation: RANDOMIZED|Intervention Model: PARALLEL|Masking: DOUBLE (INVESTIGATOR, OUTCOMES_ASSESSOR)|Primary Purpose: TREATMENT
Start Date: 2025-01-01
Completion Date: 2027-09-28
Locations: School of public health and primary care, Hong Kong, Hong Kong

Summary:
Background: Isometric resistance exercises (IREs) have great potential to improve blood pressure (BP) control. However, the effectiveness of IREs in reducing HT is still unknown because their hypotensive effects have not been detected using ambulatory BP measurements (ABPM), which are the current standard for BP measurement.

Methods: This first adequately-powered RCT will involve 390 patients with HT who do not meet the current physical activity guidelines defined by the World Health Organization. Participants will be randomly assigned in a 1:1 ratio using stratified and blocked randomization to either the IRE (wall squat) group or stretching exercise (active control) group. A well-structured, widely accepted, and validated 24-week wall squat program (2 minutes per exercise, 2 minutes of rest between sets, and 3 sessions per week) will be implemented, as it has been commonly used in previous research. Adherence to the program will be monitored using smartwatches, and regular contact with patients through social media will help ensure adherence. All patients will be followed up for 1 year to investigate the long-term effects of IREs on BP. Control group will receive exact same treatment except that IRE is replaced by frequency-matched and time-matched stretching exercise. The primary outcome measure will be systolic daytime ABPM BP at 24 weeks. Secondary outcome measures will include other BP and ABPM parameters at 12 weeks, 24weeks and 1year, cfPWV at baseline, 24 weeks and 1year, and FMD at baseline and 24weeks. Safety data will be collected and reported.

Primary Outcome Measures: daytime systolic blood pressure (BP) assessed via ambulatory blood pressure monitoring (ABPM), systolic blood pressure (SBP) measured from a 24-h ABPM, 24-week after recruitment (immediate post-intervention)
Secondary Outcome Measures: Other blood pressure indices, other BP indices from ABPM (i.e. daytime diastolic BP \[DBP\] at 24-week, daytime SBP/DBP at 1 year, and 24-hour and nighttime SBP and DBP at 24-week and 1 year), 24-week, 1 year|Carotid-femoral pulse wave velocity, This will be analysed by applanation tonometry using SphygmoCor (AtCor Medical Pty Ltd) with the accompanying SphygmoCor Software Suite (SphygmoCor System, 24-week after recruitment (immediate post-intervention)|flow-mediated dilation of brachial artery, The longitudinal image of brachial artery is obtained 5-10cm above the elbow using a high frequency linear array vascular transducer XL14 (Philips Medical Systems, Bothell, WA, USA). After a qualified image is acquired for analysis, a pressure cuff placed distal to the imaging probe at the forearm will be inflated to 50mmHg above the systolic pressure for 5 minutes. The longitudinal image of the brachial artery is scan continuous for 3 minutes after the deflation of the cuff, 24-week after recruitment (immediate post-intervention)