Cooling Strategies for Older Adults in the Heat

Aging Clinical Trial

Official title:

Acute and Chronic Interventions to Improve Heat Loss During Uncompensable Humid Heat Stress in Older Adults

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06349616
• Other study ID #: STUDY24458
• Status: Recruiting
• Phase: N/A
• Start date: May 1, 2024
• Est. completion date: December 2026

Study information

• Verified date: June 2024
• Source: Penn State University
• Contact: W. Larry Kenney, Ph.D.
• Phone: 814-863-1672
• Email: w7k[@]psu.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The earth's climate is warming, and the number of heat waves has increased in recent years. At the same time, the number of adults over the age of 65 is growing. Humans sweat and increase blood flow to the skin to cool their body when they get hot. Older adults do not do this as well as young adults. This makes it harder to safely be in warm and/or humid conditions. It is important to learn about cooling strategies for older adults to safely be in warm and/or humid conditions.

There is compelling evidence that intermittent hand and forearm cold-water immersion effectively reduces the rise of core temperature during heat stress in older adults. However, it is still unknown if this is an effective cooling strategy for older adults. Furthermore, our laboratory has shown that folic acid supplementation improves blood flow responses in older adults. This may be beneficial to older adults during heat stress.

Description:

Subjects sign an informed consent form and undergo a medical screening prior to participation. The screening includes a physical exam, anthropometry, chemical and lipid profiles.

Subjects participate in 4 experimental trials, 2 while on folic acid supplementation and 2 while on placebo. The order of treatment (folic acid supplementation or placebo) is randomized. Participants will place their hands and forearms in cold tap water intermittently for one of the two trials for each treatment. The order of the hand and forearm immersion trial is randomized for each treatment. The trials are separated by at least five days. For each experiment, core temperature, heart rate, blood pressure, skin temperature, and sweat rate are measured. Each experimental visit will last 2 hours.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: December 2026
• Est. primary completion date: December 2026
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 65 Years to 100 Years

Eligibility

Inclusion Criteria:

• Adults aged 65 and older

• English proficiency

Exclusion Criteria:

• Chron's disease, diverticulitis, or similar gastrointestinal disease

• Abnormal resting exercise electrocardiogram (ECG)

• Tobacco use

• High-risk determined by the Atherosclerotic Cardiovascular Disease (CVD) Risk Factor Assessment

• Antiepileptic or antiseizure medications

• Methotrexate

Related Conditions & MeSH terms

• Aging

Intervention

Other:
• Intermittent cold-water hand and forearm immersion
Participants will be seated at rest in a hot and humid environment. At 2 time points in the experiment, participants will place their hands and forearms in a bucket of cold tap water for 10 minutes.
• No intermittent cold-water hand and forearm immersion
Participants will be seated at rest in a hot and humid environment.

Locations

Country	Name	City	State
United States	Noll Laboratory	University Park	Pennsylvania

Sponsors (1)

Lead Sponsor	Collaborator
Penn State University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Core temperature	Core temperature will be monitored throughout each 2 hour experimental visit.	A slope of core temperature for each experimental aim is calculated and reported through study completion, an average of 1 year.
Primary	Heart rate	Heart rate will be monitored continuously throughout each 2 hour experimental visit.	A slope of heart rate for each experimental aim is calculated and reported through study completion, an average of 1 year.
Primary	Blood Pressure	Blood pressures will be taken every 10 minutes throughout each 2 hour experimental visit.	Blood pressure for each experimental aim is recorded and reported through study completion, an average of 1 year.
Secondary	Body Mass	Body weight measured on a scale	Baseline immediately before beginning the experimental visit and then once again at the end of the 2 hour experimental visit
Secondary	Skin Temperature	Average mean skin temperature	Mean skin temperature for each experimental aim is calculated and reported through study completion, an average of 1 year