Heat Therapy Versus Exercise Training in Hypertension

This is a clinical trial to determine whether 30 sessions of heat therapy in the form of hot water immersion is better than 30 sessions of traditional aerobic exercise training on blood pressure reduction in people with elevated or Stage 1 hypertension.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases; Hypertension; Arterial Hypertension
• Intervention / Treatment: Other: Heat Therapy Group; Other: Aerobic Exercise Group

Detailed Description

Hypertension accounts for more cardiovascular disease related deaths than any other modifiable risk factor. While exercise training can be effective at reducing blood pressure in some individuals, many people do not respond to exercise training, and many more are unwilling to undergo regular exercise training. Alternative options need to be explored. This is a clinical trial to determine whether 30 sessions of heat therapy in the form of hot water immersion is better than 30 sessions of traditional aerobic exercise training on blood pressure reduction in people with elevated blood pressure (hypertension). The investigators will evaluate known biomarkers of cardiovascular health. It is hypothesized that heat therapy will be superior to exercise training on blood pressure reduction.

• Study Type: Interventional
• Enrollment (Actual): 44
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Eugene, Oregon, United States, 97403
      • University of Oregon

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Systolic Blood Pressure 120 mmHg or greater and less than 180 mmHg or Diastolic Blood Pressure of 80mmHg or greater and less than 120mmHg

Exclusion Criteria:

• Secondary hypertension; diagnosed cardiovascular disease other than hypertension; taking anti-hypertensive drugs; BMI of 35 or greater; fasting glucose greater than 125 mg/dl; women who are pregnant, nursing, or desiring to become pregnant.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Heat Therapy Group; Group will undergo 30 sessions of heat therapy over approximately 10 weeks. Sessions will require subjects to be immersed in hot water for up to 45 minutes per session.	Other: Heat Therapy Group; 30 sessions of immersion in 40.5 degree celsius water for 45 minutes per session
Experimental: Aerobic Exercise Group; Group will undergo 30 sessions of aerobic exercise training over approximately 10 weeks. Sessions will require subjects to exercise on a cycle ergometer for up to 45 minutes per session.	Other: Aerobic Exercise Group; 30 sessions of aerobic exercise training for 45 minutes at 60% of VO2peak

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood Pressure Reduction: Change in Systolic and Diastolic Ambulatory Blood Pressure (mmHg) After 30 Sessions of Intervention	Ambulatory blood pressure (ABP) was measured at baseline (PRE) and after 30 heat therapy or exercise training sessions (POST) over the course of 8-10 weeks. Two individuals performed post-intervention testing after completing only 27 sessions (1 in each group). Participants arrived at the lab and were fitted with an oscillometric blood pressure cuff attached to an ambulatory blood pressure monitor. The monitor was programmed to inflate and assess blood pressure every 20 min during self-reported waking hours and every 60 min during self-reported sleeping hours. Waking and sleeping times and measurement frequency were replicated at POST within each participant. Ambulatory blood pressure data were analyzed as 24-h total for both systolic and diastolic blood pressure. Change was calculated as the value at the POST timepoint minus the value at the PRE timepoint.	10 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Arterial Stiffness: Change in Carotid-femoral Pulse Wave Velocity (m/s) From Pre (Baseline) to Post (After 30 Sessions of Intervention)	Carotid-femoral pulse wave velocity (m/s) was measured as a marker of arterial stiffness using a pressure transducing tonometer over the carotid artery and an inflated leg cuff to detect the femoral artery pulse waveform using air displacement at baseline (PRE) and after 30 heat therapy or exercise training sessions (POST) over the course of 8-10 weeks. Two individuals performed post-intervention testing after completing only 27 sessions (1 in each group). Change was calculated as the value at the POST timepoint minus the value at the PRE timepoint.	10 weeks

Collaborators and Investigators

• Sponsor: University of Oregon
• Collaborators: Oregon Health and Science University
• Investigators: Principal Investigator: Christopher T Minson, PhD, University of Oregon

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2019
• Primary Completion (Actual): December 30, 2023
• Study Completion (Actual): December 30, 2023

Study Registration Dates

• First Submitted: June 4, 2018
• First Submitted That Met QC Criteria: June 4, 2018
• First Posted (Actual): June 15, 2018

Study Record Updates

• Last Update Posted (Actual): June 4, 2025
• Last Update Submitted That Met QC Criteria: May 14, 2025
• Last Verified: September 1, 2022

More Information

Terms related to this study

• Keywords: Arterial Stiffness; Stage 1 hypertension
• Additional Relevant MeSH Terms: Vascular Diseases; Hypertension; Cardiovascular Diseases
• Other Study ID Numbers: UOregon

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified data will be placed in Research Electronic Data Capture (REDCap)
• IPD Sharing Time Frame: 1 year following completion of subject testing
• IPD Sharing Access Criteria: Access to REDCap
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No