Cardiovascular Responses to Heat Waves in the Elderly

The University of Texas System (UT)

Status: Completed

Conditions: Aging; Hyperthermia

Treatments: Other: Hot and Humid Trial; Other: Hot and Dry Trial

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT04538144

1R01AG069005-01 (U.S. NIH Grant/Contract)

STU_2019_1759

Details and patient eligibility

About

The purpose of this study is to assess the cardiovascular responses of the elderly to heat wave conditions

Full description

Heat waves are lethal and cause a disproportionate number of deaths in the elderly relative to any other age group. It is important to note that such deaths are primarily cardiovascular, not hyperthermia itself, in origin. Nevertheless, we know relatively little about the effects of aging on cardiovascular function during actual heat wave-like conditions. The central hypothesis of this work is that the elderly exhibit greater cardiovascular stress during heat wave conditions. Aim 1 will test the hypothesis that recognized impairments in thermoregulatory capacity in the elderly will culminate in heightened cardiovascular stress during prolonged exposure to heat wave conditions. Comprehensive cardiovascular and thermal responses in the elderly, relative to younger adults, will be evaluated during exposure to two prolonged heat wave conditions: hot and humid (replicating the 1995 Chicago heat wave) and very hot and dry (replicating the 2018 Los Angeles heat wave). The expected outcome from this body of work will re-shape our understanding of the consequences of aging on cardiovascular function during heat waves

Enrollment: 59 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy male and female individuals
• 18-35 years or 65+ years of age
• Free of any underlying moderate to serious medical conditions

Exclusion criteria

• Known heart disease; other chronic medical conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, uncontrolled hypertension, and uncontrolled hypercholesterolemia.
• Taking of any medications (such as beta blockers and non-dihydropyridine calcium channel blockers) that have known influences on either cardiac function or sweating responses.
• Abnormalities detected on routine screening.
• Individuals who participate in a structured aerobic exercise training program at moderate to high intensities.
• Current smokers, as well as individuals who regularly smoked within the past 3 years.
• Body mass index of greater than 30 kg/m^2
• Pregnant individuals

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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59 participants in 4 patient groups

Younger participants: Hot/Dry then Hot/Humid

Other group

Description:

Individuals aged 18-39 years who completed the hot/dry trial first and the hot/humid trial second.

Treatment:

Other: Hot and Dry Trial

Other: Hot and Humid Trial

Older participants: Hot/Dry then Hot/Humid

Other group

Description:

Individuals aged 65 years or older who completed the hot/dry trial first and the hot/humid trial second.

Treatment:

Other: Hot and Dry Trial

Other: Hot and Humid Trial

Younger participants: Hot/Humid then Hot/Dry

Other group

Description:

Individuals aged 18-39 years who completed the hot/humid trial first and the hot/dry trial second.

Treatment:

Other: Hot and Dry Trial

Other: Hot and Humid Trial

Older participants: Hot/Humid then Hot/Dry

Other group

Description:

Individuals aged 65 years or older who completed the hot/humid trial first and the hot/dry trial second.

Treatment:

Other: Hot and Dry Trial

Other: Hot and Humid Trial