AgingNCT03264508
Passive Heat Therapy and Age-associated Physiological Function
A study testing Heat therapy and Thermoneutral water immersion in people with Aging, run by Douglas Seals at 1 site in United States.
Trial summary
This study aims to determine the effects of 8-10 weeks of repeated hot water immersion ("heat therapy") vs. thermoneutral water immersion on vascular function in late middle-aged to older (55-79 years) adults. Read more about this study
- Who is it for?
- Ages 55 to 79 yearsHealthy volunteers can take part
- Conditions the study is for
- Aging
- What is being tested?
- Heat therapy and Thermoneutral water immersion
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 25 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Oct 2017to 1 Jun 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 55 to 79 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Ability to provide informed consent.
- Aged 55-79 years. Women must be postmenopausal and not taking hormone replacement therapy within the past year.
- Sedentary to recreationally active: participating in vigorous aerobic exercise <4x/wk for ≥ 3 yrs.
- Able to refrain from the use of dietary supplements, anti-inflammatory medications, and prescription medications for 24-48h prior to experimental testing.
- Generally healthy (no overt clinical disease), as determined by medical history, physical examination, blood and urine chemistries.
- Ankle-brachial blood pressure index >0.7
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- Total cholesterol <240 mg/dl (<6.2 mmol/L)
- Fasting plasma glucose <126 mg/dl (<7.0 mmol/L)
- Systolic blood pressure < 160 mmHg and >100 mmHg
- Glomerular filtration rate > 60 ml/min/1.73 m2
- Mini mental state exam score > 20 points
- Body mass index (BMI) <30 kg/m2
- Weight stable in the prior 3 months (≤ 2 kg weight change) and willing to remain weight stable over the course of the study
- Free from alcohol dependence or abuse, as defined by the American Psychiatry Association, Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).
Who cannot join
- Current use of certain prescription medications that may interfere with thermoregulation and/or blood pressure control during heat stress. These include anti-hypertensives (in particular beta-blockers), nitrates and nitrites (e.g. nitroglycerin), PDE5 inhibitors (e.g. Viagra), anticholinergics (e.g. amitriptyline), and alpha-blockers (e.g. Flomax).
- Orthostatic hypotension
- Current or past smoking within the last 5 years
- Recent major change in health status within previous 6 months (i.e. surgery, significant infection or illness).
- Chronic clinical diseases (e.g., inflammatory bowel diseases/irritable bowel syndrome, coronary artery/peripheral artery/cerebrovascular diseases, diabetes, chronic kidney disease requiring dialysis, neurological disorders or diseases that may affect motor/cognitive functions [multiple sclerosis, Parkinson's disease, polio, Alzheimer's disease, dementia or other brain diseases of aging]).
- History of heat-related illness
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- Open wounds or skin lesions. History of skin-related conditions or sensitivities to prolonged water immersion or exposure to pool chemicals.
- Blood donation within the past 2 months
- Inability to tolerate blood draws, intravenous catheters, and/or fingertip blood sampling, including past fainting in response to blood sampling.
- Rectal, anal, vaginal, or prostate surgery within the last 6 months, current or recent (within the last 6 months) hemorrhoids, or related concerns regarding use of rectal thermistor
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Colorado Boulder
Boulder, Colorado, 80309
About this study
This study aims to determine the effects of 8-10 weeks of repeated hot water immersion ("heat therapy") vs. thermoneutral water immersion on vascular function in late middle-aged to older (55-79 years) adults.
Read the detailed description
Advancing age is the primary risk factor for cardiovascular diseases (CVD), which remain the leading cause of death in the developed world. The key process that links aging to increased risk of CVD is the development of arterial dysfunction, including impaired endothelial function and arterial stiffening. In addition, age-associated impairments in arterial function have been linked to other diseases/disorders of aging, including cognitive impairments, Alzheimer's disease and dementia, and motor disorders/disability.
Passive heat therapy, in the form of repeated use of hot baths and saunas, has been used by several cultures for centuries; however, the physiological benefits are only now being elucidated. For example, recent studies have found that lifelong habitual sauna use is associated with considerably reduced risk of all-cause mortality, sudden cardiac death, CVD-related death, and Alzheimer's disease and dementia. In addition, 8-10 weeks of hot water immersion in young adults has been shown to improve endothelial function and reduces arterial stiffness and blood pressure. Therefore, the investigators expect heat therapy to similarly improve vascular function, as well as cognitive and motor function, in middle-aged to older adults who are at greater risk of CVD and related diseases/disorders.
- Conditions
- Aging
- Being tested
- Heat therapy, Thermoneutral water immersion
- Keywords
- endothelial function, arterial stiffness, heat, hot water immersion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heat therapyBehavioural
30 sessions (3-4x per week for 8-10 weeks) of hot water immersion in 40°C water, sufficient to raise body core temperature to 38.5°C.
Thermoneutral water immersionBehavioural
30 sessions (3-4x per week for 8-10 weeks) of hot water immersion in 36°C water to prevent changes in body core temperature >0.2°C.
| Study group | Role | What they receive |
|---|---|---|
| Heat therapy | Experimental | Hot water immersion 3-4x per week for 8-10 weeks Receives: Behavioral: Heat therapy |
| Thermoneutral water immersion | Sham comparator | Thermoneutral water immersion 3-4x per week for 8-10 weeks Receives: Behavioral: Thermoneutral water immersion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Brachial artery flow-mediated dilation
Measure of endothelial function
Measured: 0 and 8 weeks
Carotid-femoral pulse wave velocity
Measure of central arterial stiffness
Measured: 0 and 8 weeks
Mean arterial blood pressure
Brachial artery blood pressure, measured in triplicate (and averaged) following 20 min of supine rest
Measured: 0 and 8 weeks
Secondary outcomes (3)
Cerebrovascular reactivity
Measure of cerebral vascular function; magnitude of increase in blood flow through the middle cerebral artery in response to breathing 5% CO2
Measured: 0 and 8 weeks
Fluid cognition composite score
Multiple domains of cognitive function (incl. executive function, memory, processing speed) assessed using the NIH toolbox (aggregated into one reported value)
Measured: 0 and 8 weeks
Motor function composite score
Multiple domains of motor function (incl. endurance, strength, dexterity) assessed using the NIH toolbox (aggregated into one reported value)
Measured: 0 and 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Aug 2017
- Study start25 Oct 2017
- Primary completion23 Nov 2020
- Study completion1 Jun 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for AgingStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, controlled (parallel design), single-blind
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 25 participants (actual)
Sponsor and investigators
- Lead sponsor
- Douglas Seals
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Douglas Seals, University of Colorado, Boulder
- Investigators
- Douglas R Seals, PhD, Principal investigator, University of Colorado, Boulder
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03264508
- Sponsor's protocol ID
- 16-0757
- Status last verified
- Oct 2021
- First submitted
- 22 Aug 2017
- Last updated
- 28 Oct 2021
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Brunt VE, Howard MJ, Francisco MA, Ely BR, Minson CT. Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans. J Physiol. 2016 Sep 15;594(18):5329-42. doi: 10.1113/JP272453. Epub 2016 Jun 30.
PubMed 27270841
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Passive Heat Therapy and Age-associated Physiological Function
- ClinicalTrials.gov ID
- NCT03264508
- Acronym / sponsor ID
- 16-0757
- Conditions
- Aging
- Keywords
- endothelial function, arterial stiffness, heat, hot water immersion
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 25 participants (actual)
- Lead sponsor
- Douglas SealsUniversity, hospital or other
- Study start
- 25 Oct 2017 (actual)
- Primary completion
- 23 Nov 2020 (actual)
- Study completion
- 1 Jun 2021 (actual)
- First posted
- 29 Aug 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to determine the effects of 8-10 weeks of repeated hot water immersion ("heat therapy") vs. thermoneutral water immersion on vascular function in late middle-aged to older (55-79 years) adults.
Detailed description
Advancing age is the primary risk factor for cardiovascular diseases (CVD), which remain the leading cause of death in the developed world. The key process that links aging to increased risk of CVD is the development of arterial dysfunction, including impaired endothelial function and arterial stiffening. In addition, age-associated impairments in arterial function have been linked to other diseases/disorders of aging, including cognitive impairments, Alzheimer's disease and dementia, and motor disorders/disability.
Passive heat therapy, in the form of repeated use of hot baths and saunas, has been used by several cultures for centuries; however, the physiological benefits are only now being elucidated. For example, recent studies have found that lifelong habitual sauna use is associated with considerably reduced risk of all-cause mortality, sudden cardiac death, CVD-related death, and Alzheimer's disease and dementia. In addition, 8-10 weeks of hot water immersion in young adults has been shown to improve endothelial function and reduces arterial stiffness and blood pressure. Therefore, the investigators expect heat therapy to similarly improve vascular function, as well as cognitive and motor function, in middle-aged to older adults who are at greater risk of CVD and related diseases/disorders.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (investigator)
- Number of arms
- 2
- Model description
- Randomized, controlled (parallel design), single-blind
| Arm | Type | Receives |
|---|---|---|
| Heat therapy | Experimental | Behavioral: Heat therapyHot water immersion 3-4x per week for 8-10 weeks |
| Thermoneutral water immersion | Sham comparator | Behavioral: Thermoneutral water immersionThermoneutral water immersion 3-4x per week for 8-10 weeks |
Who may qualify
- Ages
- 55 to 79 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (14 listed)
- Ability to provide informed consent.
- Aged 55-79 years. Women must be postmenopausal and not taking hormone replacement therapy within the past year.
- Sedentary to recreationally active: participating in vigorous aerobic exercise <4x/wk for ≥ 3 yrs.
- Able to refrain from the use of dietary supplements, anti-inflammatory medications, and prescription medications for 24-48h prior to experimental testing.
- Generally healthy (no overt clinical disease), as determined by medical history, physical examination, blood and urine chemistries.
Key exclusion criteria (10 listed)
- Current use of certain prescription medications that may interfere with thermoregulation and/or blood pressure control during heat stress. These include anti-hypertensives (in particular beta-blockers), nitrates and nitrites (e.g. nitroglycerin), PDE5 inhibitors (e.g. Viagra), anticholinergics (e.g. amitriptyline), and alpha-blockers (e.g. Flomax).
- Orthostatic hypotension
- Current or past smoking within the last 5 years
- Recent major change in health status within previous 6 months (i.e. surgery, significant infection or illness).
- Chronic clinical diseases (e.g., inflammatory bowel diseases/irritable bowel syndrome, coronary artery/peripheral artery/cerebrovascular diseases, diabetes, chronic kidney disease requiring dialysis, neurological disorders or diseases that may affect motor/cognitive functions [multiple sclerosis, Parkinson's disease, polio, Alzheimer's disease, dementia or other brain diseases of aging]).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Heat therapy30 sessions (3-4x per week for 8-10 weeks) of hot water immersion in 40°C water, sufficient to raise body core temperature to 38.5°C. | Behavioural | Heat therapy |
| Thermoneutral water immersion30 sessions (3-4x per week for 8-10 weeks) of hot water immersion in 36°C water to prevent changes in body core temperature >0.2°C. | Behavioural | Thermoneutral water immersion |
Primary outcome
Brachial artery flow-mediated dilation
Time frame: 0 and 8 weeks
Measure of endothelial function
Carotid-femoral pulse wave velocity
Time frame: 0 and 8 weeks
Measure of central arterial stiffness
Mean arterial blood pressure
Time frame: 0 and 8 weeks
Brachial artery blood pressure, measured in triplicate (and averaged) following 20 min of supine rest
3 secondary outcomes
Cerebrovascular reactivity
Time frame: 0 and 8 weeks
Fluid cognition composite score
Time frame: 0 and 8 weeks
Motor function composite score
Time frame: 0 and 8 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2021.
- Background: PubMed 27270841Brunt VE, Howard MJ, Francisco MA, Ely BR, Minson CT. Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans. J Physiol. 2016 Sep 15;594(18):5329-42. doi: 10.1113/JP272453. Epub 2016 Jun 30.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Douglas R Seals, PhD principal investigator
University of Colorado, Boulder
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Heat therapy and Thermoneutral water immersion in people with Aging, run by Douglas Seals at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Oct 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Brachial artery flow-mediated dilation (time frame: 0 and 8 weeks). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03264508, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2021.