Heat Waves and the Elderly - Cooling Modalities

Aging Clinical Trial

Official title:

Heat Waves in the Elderly: Reducing Thermal and Cardiovascular Consequences

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05484739
• Other study ID #: STU-2022-0625
• Status: Recruiting
• Phase: N/A
• Start date: February 21, 2023
• Est. completion date: August 31, 2026

Study information

• Verified date: April 2024
• Source: University of Texas Southwestern Medical Center
• Contact: Zachary McKenna, PhD
• Phone: 214-345-6557
• Email: ZacharyMckenna[@]texashealth.org
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to assess how well cooling modalities work in reducing cardiovascular stress of the elderly to heat wave conditions

Description:

Heat waves are lethal and cause a disproportionate number of deaths in the elderly relative to any other age group. Such deaths are primarily cardiovascular, not hyperthermia itself, in origin. The central hypothesis of this work is that cardiovascular stress during heat wave conditions in the elderly can be reduced by applying low-energy cooling modalities. Comprehensive cardiovascular and thermal responses in the elderly will be evaluated during exposure to two prolonged heat wave conditions: hot and humid (replicating the 1995 Chicago heat wave), very hot and dry (replicating the 2018 Los Angeles heat wave). With each of these heat wave conditions individuals will be exposed to the following cooling modalities: no cooling (control), water spray, fan use, and fan use plus water spray.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 50
• Est. completion date: August 31, 2026
• Est. primary completion date: October 1, 2025
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 65 Years and older

Eligibility

Inclusion Criteria:

• 65 years of age or older
• Free of any significant underlying medical problems based upon a detailed medical history and physical exam

Exclusion Criteria:

• Known heart disease
• Other chronic medical conditions requiring regular medical therapy including cancer, diabetes, uncontrolled hypertension, and uncontrolled hypercholesterolemia etc;
• Abnormality detected on routine screening suggestive of provokable ischemia or previously undetected cardiac disease or resting left bundle branch block on screening electrocardiogram.
• Current smokers, as well as individuals who regularly smoked within the past 3 years
• Subject with a body mass index =31 kg/m2
• Pregnant individuals

Related Conditions & MeSH terms

• Aging
• Hyperthermia

Intervention

Other:
• Water Spray
Participants will receive water spraying on their body throughout the climate chamber exposure.
• Fan
Participants will be exposed to a fan throughout the climate chamber exposure.
• Water Spray and Fan
Participants will receive both water spraying and a fan throughout the climate chamber exposure.
• Control
Participants will NOT receive either water spray or a fan exposure.

Locations

Country	Name	City	State
United States	Texas Health Presbyterian Hospital Dallas	Dallas	Texas

Sponsors (1)

Lead Sponsor	Collaborator
University of Texas Southwestern Medical Center

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in core body temperature	Change in core body temperature will be measured either from a temperature sensor pill or from a rectal thermometer	Body core temperature will be obtained within 60 min before the heat wave exposure after the 3 hour heat wave exposure.
Primary	Change in left ventricular function	Measures of left ventricular function, such as ventricular wall motion and ventricular filling, will be obtained from echocardiography images.	Within 60 minutes before each simulated heat wave exposure, around minute 90 of the heat wave exposure, and at the end of the 3 hour heat wave exposure
Secondary	Heart rate	Heart rate will be measured from ECG electrodes attached to the participant	Prior to and throughout each simulated heat wave exposure; approximately 420 minutes
Secondary	Cardiac output	Cardiac output (how much blood is ejected from the heart) will be measured using 3D echocardiography.	Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)
Secondary	Arterial blood pressure	Arterial blood pressure will be measured using a standard arm blood pressure cuff.	Prior to and throughout each simulated heat wave exposure; an average of 480 minutes
Secondary	Whole body sweat rate	Whole body sweat rate will be measured by through nude weight of the participant.	Within 60 minutes before each simulated heat wave exposure and within 30 minutes after each heat wave exposure.
Secondary	Markers of renal function and injury - Cystatin C	Markers of renal function and injury (e.g., cystatin C) will be evaluated from blood sampling collection.	Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure
Secondary	Markers of renal function and injury - Creatinine Clearance	Markers of renal function and injury (e.g., creatinine clearance) will be evaluated from blood sampling and urine collection.	Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure
Secondary	Markers of renal function and injury - Insulin-like growth factor-binding protein 7	Markers of renal function and injury (e.g., Insulin-like growth factor-binding protein 7) will be evaluated from urine sampling.	Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure
Secondary	Markers of renal function and injury - Tissue inhibitor of metalloproteinases 2	Markers of renal function and injury (e.g., Tissue inhibitor of metalloproteinases 2) will be evaluated from urine sampling.	Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure
Secondary	Cerebral perfusion	Cerebral perfusion will be measured by Doppler ultrasound of the internal carotid and vertebral arteries.	Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)
Secondary	High sensitive cardiac troponin	A plasma-based marker of cardiac stress (high sensitive cardiac troponin) be evaluated from blood sampling.	Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure
Secondary	Skin temperature	Skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin	Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)
Secondary	Forced vital capacity (FVC)	Forced vital capacity will be obtained from spirometry	Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)