Warm water soak could boost aging blood vessels, early study hints
NCT ID NCT06633198
First seen Jun 24, 2026 · Last updated Jul 10, 2026 · Updated 3 times
Summary
This early-phase study tests whether soaking the lower legs in warm water (42°C) for an hour can improve how small blood vessels widen in response to increased blood flow. Researchers will study 20 healthy adults aged 18-80 to see if this passive heating mimics some benefits of exercise. The goal is to understand the role of nitric oxide and cellular recycling processes in any observed improvements.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Passive heating (warm water immersion) and L-NAME (a drug used to test nitric oxide involvement)
- What this could lead to
- If successful, this study could point toward passive heat therapy as a way to improve blood vessel function in older adults, potentially reducing cardiovascular risk without requiring exercise.
- What could go wrong
- This is a very early, small study (20 participants) that only measures short-term effects. It may not translate into long-term benefits or apply to broader populations.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Early phase 1
The earliest testing in people: a first look at safety, in a very small group.
- Participants
-
About 20 people
The number the study aims to enrol. It can still change while the study runs.
- Started
-
May 2025
- Expected to finish
-
Dec 2028
An estimate. End dates often move.
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
18 to 80 years
- Sex
-
Anyone
- Healthy volunteers
-
Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Participants must be between 18-80 yrs. of age * No more than 1 cardiovascular risk factor (see list in exclusion criteria) Exclusion Criteria: * Cardiovascular Risk Factors * Uncontrolled/unmanaged hypertension and/or use of current anti-hypertensive therapy * Current Tobacco product use or within last 6 months * BMI greater than 30 * Hyperlipidemia - diagnosed and/or taking medications to manage * Hypercholesterolemia - diagnosed and/or taking medications to manage (e.g. statins) * Type 1 or Type 2 Diabetes * Use of anti-coagulant or anti-platelet drugs * Use of beta blockers * Symptomatic coronary artery disease * Diagnosed Heart Failure (Any classification above Class I as defined by NY Heart Association) * Diagnosed renal impairment Renal impairment defined, according to National Kidney Foundation as abnormalities of kidney structure or function, present for greater than 3 months, including: * Albuminuria (ACR ≥ 30 mg/g) * Urine sediment abnormalities * Electrolyte and other abnormalities due to tubular disorders * Structural abnormalities detected by imaging * History of kidney transplantation * Decreased glomerular filtration rate (GFP \< 60 mL/min/1.73 m2) * Current Hormone Replacement Therapy Use * History of retinopathy * Documented neuromuscular disorders * Porphyria Cutanea Tarda (blistering of skin to sun; photosensitivity) * Pregnancy (Young Female subjects) * Allergies to povidone iodine * Tattoos on lower arm (forearm) * Use of erectile dysfunction medication in the past 6 months * Use of topical/non-topical steroids in last 6 months (e.g. cortisone cream) * Active anti-cancer treatment or treatment within last 12 months * Active COVID-19 or within the past 3 months * Gender Reassignment Therapy
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Genom att skicka in godkänner du våra Användarvillkor
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Medical College of Wisconsin
Milwaukee, Wisconsin, 53226, United States
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