Clinical trial NCT04026126: Effects of Passive Heat Therapy on Oxygen Consumption and Cardiovascular Fitness in Adults
Official title: Effects of Passive Heat Therapy on Oxygen Consumption and Cardiovascular Fitness in Adults
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Heart Failure
Heart Diseases
Cardiovascular Diseases
Endothelial Dysfunction
Keywords: Heat Therapy
Lead sponsor: University of Kansas Medical Center
Sponsor class: OTHER
Collaborators: name: National Institute of General Medical Sciences (NIGMS)
First posted: 2019-07-19
Enrollment: 15
Sex: ALL
Minimum age (years): 50
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to determine if enhanced endothelial arterial distensibility observed with heat therapy translates into improved cardiorespiratory fitness. The following aims are proposed: Aim 1: to determine if chronic heat therapy results in improvements in cardiovascular function. Aim 2: To examine potential mechanism(s) of action of heat therapy in cardiovascular function.

Detailed description: The National Institute of Health recognizes heart failure as a major public health problem with a prevalence of over 5.8 million Americans and 23 million people worldwide. Commonly prescribed medications to treat the symptoms associated with this disease are expensive and many are not covered by major health insurance companies. There is a critical need to develop novel treatment and prevention strategies for heart failure. Emerging research highlights the benefits of heat therapy (HT) on metabolic and cardiovascular disease risk. The Geiger laboratory has demonstrated that in obese rats fed a high- fat diet for 12 weeks, weekly HT restored whole body glucose tolerance and skeletal muscle insulin sensitivity. The first comprehensive investigation of long-term HT in young, sedentary humans resulted in improved endothelial function and hemodynamics that were on par with what is typically observed with exercise training in previously sedentary subjects. The purpose of this pilot study is to determine if the enhanced endothelial arterial distensibility observed with HT translates into improved cardiorespiratory fitness. The following aims are proposed:

Aim 1: To determine if chronic HT results in improvements in cardiovascular function. The study team hypothesizes that repeated HT will result in improvement in hemodynamic variables related to arterial distensibility (blood pressure, stroke volume, stroke volume variation, cardiac index and systemic vascular resistance) and that these changes translate to improved cardiovascular function as measured by VO2max.

Aim 2: To examine potential mechanism(s) of action of HT in cardiovascular function. The study team hypothesizes that HT may exerts its beneficial effects via the effect of heat shock proteins (HSPs) on Nitric Oxide (NO) bioavailability. This will be tested by measuring HSPs, NO mediators and inflammatory markers at baseline and post-intervention. There is rapidly growing interest in the use of HT as a global therapeutic approach and alternative or complementary therapy to exercise training for patients with chronic disease. Study findings would be clinically significant as both men and women with higher cardiorespiratory fitness (as indicated by maximal oxygen consumption, VO2max) are at lower risk for cardiovascular disease.

These studies will be the first to examine the ability of chronic heat therapy to increase cardiorespiratory fitness as measured by maximal oxygen consumption, VO2max. These findings could lead to HT as a simple and effective tool for improving cardiovascular health in a variety of populations, particularly those with exercise limitations and comorbid disease states like type 2 diabetes, dementia and cardiovascular disease.

Eligibility criteria: Exclusion Criteria:

* Current major cardiovascular disease (i.e.: recent myocardial infarction (heart attack), stroke, angina pectoris, high grade coronary vasculopathy or atherosclerosis, severe valvular disease, cardiac dysrhythmia that requires treatment.
* Current treatment with steroids or immunosuppressive agents
* Cancer
* Serious liver disease
* End-stage renal disease
* Judgement by medical provider that heat therapy poses an undue burden or risk
* Women who are pregnant or plan to become pregnant

Primary outcomes:
measure: Change in Blood Pressure
timeFrame: Blood pressure will be assessed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit). As a safety measure only, blood pressure will be monitored during every heat therapy treatment.
measure: Change in Stroke Volume
timeFrame: Stroke volume will be assessed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Stroke Volume Variation
timeFrame: Stroke volume variation will be assessed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Cardiac Index
timeFrame: Cardiac index will be assessed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Systemic Vascular Resistance
timeFrame: Systemic vascular resistance will be assessed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Maximum Oxygen Consumption (VO2max)
timeFrame: VO2max assessment will be performed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Concentration of Heat Shock Proteins
timeFrame: Blood analyses will be performed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Concentration of Nitric Oxide
timeFrame: Blood analyses will be performed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
measure: Change in Concentration of Pro/Anti-inflammatory Markers
timeFrame: Blood analyses will be performed at baseline and 24-48 hours after the last heat therapy session (end of study, ~2.5 weeks after first study visit).
Secondary outcomes:
Other outcomes:
Locations:
city: Kansas City
country: United States
facility: University of Kansas Medical Center
state: Kansas
Study officials:
affiliation: University of Kansas Medical Center
name: Paige C Geiger, Ph.D.
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Kansas Medical Center
name: Brigid Flynn, MD
role: PRINCIPAL_INVESTIGATOR
References: