Heat Therapy for High Blood Pressure
What You Need to Know Before You Apply
What is the purpose of this trial?
The prevalence of hypertension is greater in older women than men, while the blood pressure (BP) control rate is lower in older women in US. Uncontrolled hypertension is a major risk factor for cardiovascular morbidity/mortality. Despite standard therapy and adherence to optimal drug regimens, \>50% of older hypertensive women still have inadequate BP control, and the control rate is further reduced with more aggressive BP targets recommended recently by the new Hypertension Guidelines. Thus, the effectiveness of drug treatment alone in the control of hypertension among older women is limited; hence, non-pharmacological approaches are also needed to help reduce BP in older hypertensive women. One adjuvant, non-pharmacological approach that offers promise in lowering BP is "heat therapy". Indeed, repeated whole-body heat exposure decreases BP in healthy humans. Whether this is also true after regional limb heating in hypertensive patients is unknown. The objectives of this research are to investigate the BP lowering effect of home-based lower leg heat therapy in older women with hypertension, and to examine the impact of this therapeutic modality on neural-vascular health in these patients. Aim 1 will test the hypothesis that chronic lower leg heat therapy combined with an antihypertensive drug is superior to drug treatment alone in lowering BP in older hypertensive women. We will randomly assign older hypertensive women to either an intervention group or a control group. Patients in the intervention group will perform 8 weeks of lower leg heat therapy via water immersion up to the knee in a circulated bath (water temperature 42°C, 4 times/week, 45 min/session), whereas patients in the control group will immerse their legs in a thermoneutral water bath (33°C) at the same frequency and duration. All patients will also receive a fixed dose of chlorthalidone (a diuretic, 25 mg orally daily). We will compare ambulatory BP, the BP control rate, and patient adherence and acceptability to treatment between the groups. Aim 2 will test the hypothesis that chronic lower leg heat therapy will improve nitric oxide bioavailability which can decrease sympathetic vasoconstriction and improve vascular function in older hypertensive women. We will use state-of-the-art techniques of microneurography, Doppler ultrasound, applanation tonometry, and cutaneous microdialysis to assess neural control, vasodilator function, and interstitial metabolites (i.e. nitrate and nitrite) indicative of basal nitric oxide bioavailability in all patients enrolled in Aim 1 before and after 8 weeks of heat therapy. Information obtained from this research project will guide evidence-based clinical practice. It is anticipated that our study may lead to revision of hypertension guidelines to incorporate home-based heat therapy as adjuvant to antihypertensive drug(s) for older women, as well as other patient populations.
Do I need to stop my current medications for this trial?
The trial does not specify if you need to stop your current medications. However, all participants will receive a fixed dose of chlorthalidone, a diuretic, as part of the study. If you are on three or more antihypertensive agents, you are not eligible for the trial.
What safety data exists for heat therapy in treating high blood pressure?
The studies reviewed indicate that heat therapy, including lower leg and local passive heat, is generally well-tolerated and shows potential benefits in reducing blood pressure and improving vascular function. In patients with peripheral artery disease, leg heat therapy was well-tolerated with high adherence, and it improved perceived physical function. In patients with autonomic failure, local heat therapy effectively lowered blood pressure without significant adverse effects. However, further studies are needed to confirm these findings and assess long-term safety and efficacy.12345
Is heat therapy a promising treatment for high blood pressure?
What data supports the idea that Heat Therapy for High Blood Pressure is an effective treatment?
The available research shows that heat therapy can effectively lower blood pressure. One study found that heat therapy reduced both systolic and diastolic blood pressure, which are measures of the pressure in your arteries when your heart beats and rests. Another study compared heat therapy to exercise and found that heat therapy reduced systolic blood pressure more than exercise did. Additionally, a case report showed that leg bathing, a form of heat therapy, significantly lowered blood pressure in a patient after surgery. These findings suggest that heat therapy is a promising treatment for managing high blood pressure.15679
Who Is on the Research Team?
Qi Fu, MD, PhD
Principal Investigator
University of Texas Southwestern Medical Center
Steven Romero, PhD
Principal Investigator
University of North Texas Health Science Center
Are You a Good Fit for This Trial?
This trial is for older women aged 65-85 with high blood pressure, who speak English and can perform home-based heat therapy. It's not suitable for those with severe hypertension, cardiopulmonary disease, kidney disease, diabetes, substance abuse history (except tobacco), current smokers, or those on hormone replacement therapy.Inclusion Criteria
Exclusion Criteria
Timeline for a Trial Participant
Screening
Participants are screened for eligibility to participate in the trial
Wash-out
Patients gradually stop taking their own antihypertensive medications and undergo 24-hour ambulatory BP monitoring
Run-in
Patients are treated with a fixed dose of chlorthalidone and monitored for BP and drug tolerability
Treatment
Participants receive lower leg heat therapy or control treatment with chlorthalidone
Follow-up
Participants are monitored for safety and effectiveness after treatment
What Are the Treatments Tested in This Trial?
Interventions
- Lower leg heat therapy
Find a Clinic Near You
Who Is Running the Clinical Trial?
University of Texas Southwestern Medical Center
Lead Sponsor