Clinical trial NCT06349616: Cooling Strategies for Older Adults in the Heat
Official title: Acute and Chronic Interventions to Improve Heat Loss During Uncompensable Humid Heat Stress in Older Adults
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Aging
Keywords: Aging
Thermoregulation
Heat Stress
Lead sponsor: Penn State University
Sponsor class: OTHER
First posted: 2024-04-05
Enrollment: 20
Sex: ALL
Minimum age (years): 65
Maximum age (years): 100
Standard ages: OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Subjects participate in 4 experiments, 2 for each treatment (folic acid supplementation and placebo). The order of treatment is random.
Primary purpose: BASIC_SCIENCE

Brief 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.

Detailed 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.

Eligibility criteria: 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

Primary outcomes:
measure: Core temperature
timeFrame: A slope of core temperature for each experimental aim is calculated and reported through study completion, an average of 1 year.
measure: Heart rate
timeFrame: A slope of heart rate for each experimental aim is calculated and reported through study completion, an average of 1 year.
measure: Blood Pressure
timeFrame: Blood pressure for each experimental aim is recorded and reported through study completion, an average of 1 year.
Secondary outcomes:
measure: Body Mass
timeFrame: Baseline immediately before beginning the experimental visit and then once again at the end of the 2 hour experimental visit
measure: Skin Temperature
timeFrame: Mean skin temperature for each experimental aim is calculated and reported through study completion, an average of 1 year
Other outcomes:
Locations:
city: University Park
country: United States
facility: Noll Laboratory
state: Pennsylvania
Study officials:
affiliation: The Pennsylvania State University
name: W. Larry Kenney, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References: