NCT05618197

Brief Summary

Aging is associated with a decline in cardiovascular health, cognitive function and losses in muscle strength, with half or more of those over age 65 suffering from two or more comorbidities (e.g., heart disease, type 2 diabetes). The worldwide population of older adults is growing rapidly, with one in six people expected to be over age 65 by 2050. This will place further financial burden from chronic diseases on already stressed healthcare systems. While studies show that frequent exercise is an effective way for older adults to maintain or improve cardiovascular and metabolic health, older individuals are less physically active and do not adhere well to exercise programs, often due to physical or medical limitations. Therefore, alternative methods for older adults to get the same health benefits as exercise require further exploration. Recent work has shown that passive heat therapy may be one such alternative solution.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
19

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started May 2023

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

November 8, 2022

Completed
8 days until next milestone

First Posted

Study publicly available on registry

November 16, 2022

Completed
6 months until next milestone

Study Start

First participant enrolled

May 23, 2023

Completed
2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 6, 2025

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 6, 2025

Completed
Last Updated

August 6, 2025

Status Verified

March 1, 2025

Enrollment Period

2 years

First QC Date

November 8, 2022

Last Update Submit

August 1, 2025

Conditions

Aging

Keywords

Passive heatingEndothelial functionHeat shock proteinsCognitive functionMuscle strength

Outcome Measures

Primary Outcomes (1)

  • Brachial artery flow-mediated dilation

    Percentage change from baseline in brachial artery diameter assessed by ultrasound.

    Pre and post 6 weeks of passive heating and pre and post 6 weeks no intervention with 6 weeks washout between arms

Secondary Outcomes (33)

  • Brachial and carotid artery blood flow velocity

    Pre and post 6 weeks of passive heating and pre and post 6 weeks no intervention with 6 weeks washout between arms

  • Carotid vessel diameter

    Pre and post 6 weeks of passive heating and pre and post 6 weeks no intervention with 6 weeks washout between arms

  • Carotid intima-media thickness

    Pre and post 6 weeks of passive heating and pre and post 6 weeks no intervention with 6 weeks washout between arms

  • Carotid compliance

    Pre and post 6 weeks of passive heating and pre and post 6 weeks no intervention with 6 weeks washout between arms

  • Carotid distensibility

    Pre and post 6 weeks of passive heating and pre and post 6 weeks no intervention with 6 weeks washout between arms

  • +28 more secondary outcomes

Study Arms (2)

Passive heating intervention

EXPERIMENTAL

\~3x per week of 1 h hot water immersion (to the clavicle, @40°C, rectal temperature \~38.5°C and \<39°C) sessions over a period of 6 weeks.

Other: Passive heating

Control

NO INTERVENTION

6 weeks of no hot water immersion

Interventions

Passive heatingOTHER

\~3x per week of 1 h hot water immersion (to the clavicle, @40°C, rectal temperature \~38.5°C and \<39°C) sessions over a period of 6 weeks.

Passive heating intervention

Eligibility Criteria

Age55 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Male or female age ≥ 55
  • Free from cardiometabolic disease
  • Body mass index of 18-35 kg/m2
  • Receipt of a normal 12-lead ECG approved by the School Independent Medical Officer
  • Capacity to understand and provide their written, informed consent to participate in the study protocol

You may not qualify if:

  • Unable to understand or cooperate with the study protocol due to learning difficulties or otherwise
  • Any current, or past medical (last five years), history of any cardiovascular, respiratory, cancer, renal, hepatic, gastrointestinal, haematological, lymphatic, neurological, psychiatric, or any other disease or diseases.
  • Any regular medication for the last five years (not including acute courses of treatment of less than one month for discrete, resolved conditions).
  • Medications that may influence physiological responses to the passive heating intervention Uncontrolled hypertension (≥ 150 mmHg systolic and/or ≥ 90 mmHg diastolic)
  • Body mass index of \> 35 kg/m2
  • Recent long-term exposure to a hot climate (within the previous three months)
  • Current smoker (or have stopped smoking within the previous three months)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Spinnaker Building

Portsmouth, Hampshire, PO4 0SU, United Kingdom

Location

Study Officials

  • Zoe Saynor, PhD

    University of Portsmouth

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Senior Lecturer

Study Record Dates

First Submitted

November 8, 2022

First Posted

November 16, 2022

Study Start

May 23, 2023

Primary Completion

June 6, 2025

Study Completion

June 6, 2025

Last Updated

August 6, 2025

Record last verified: 2025-03

Locations

GB(1)