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Cardiovascular Responses to Heat Waves in the Elderly

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ClinicalTrials.gov Identifier: NCT04538144
Recruitment Status : Recruiting
First Posted : September 3, 2020
Last Update Posted : February 4, 2021
Sponsor:
Information provided by (Responsible Party):
Craig Crandall, University of Texas Southwestern Medical Center

Tracking Information
First Submitted Date August 28, 2020
First Posted Date September 3, 2020
Last Update Posted Date February 4, 2021
Actual Study Start Date January 19, 2021
Estimated Primary Completion Date August 31, 2022   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures
 (submitted: September 2, 2020)
  • Core body temperature [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]
    Core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill.
  • Measures of left ventricular function [ Time Frame: Prior to, during, and after each simulated heat wave exposure; approximately 20 min each ]
    Measures of left ventricular function, such as ventricular wall motion and ventricular filling, will be obtained from echocardiography images.
Original Primary Outcome Measures Same as current
Change History
Current Secondary Outcome Measures
 (submitted: September 2, 2020)
  • Skin temperature [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]
    Skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin
  • Heart rate [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]
    Heart rate will be measured from ECG electrodes attached to the participant
  • Arterial blood pressure [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]
    Arterial blood pressure will be measured using a standard arm blood pressure cuff
  • Cardiac output [ Time Frame: Prior to, during, and after each simulated heat wave exposure; approximately 20 min each ]
    Cardiac output (how much blood is ejected from the heart) will be measured using echocardiography and nitrous oxide rebreathing approaches.
  • Cerebral perfusion [ Time Frame: Prior to, during, and after each simulated heat wave exposure; approximately 20 min each ]
    Cerebral perfusion will be measured by doppler ultrasound of the internal carotid and vertebral arteries
Original Secondary Outcome Measures Same as current
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title Cardiovascular Responses to Heat Waves in the Elderly
Official Title Heat Waves in the Elderly: Reducing Thermal and Cardiovascular Consequences
Brief Summary The purpose of this study is to assess the cardiovascular responses of the elderly to heat wave conditions
Detailed 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), 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
Study Type Observational
Study Design Observational Model: Cohort
Time Perspective: Prospective
Target Follow-Up Duration Not Provided
Biospecimen Not Provided
Sampling Method Non-Probability Sample
Study Population The study population will be healthy younger and older individuals identified from the general population.
Condition
  • Aging
  • Hyperthermia
Intervention Other: Simulated heat wave
Individuals will be exposed to thermoneutral climate conditions and two simulated heat wave conditions.
Study Groups/Cohorts
  • Younger participants
    Individuals aged 18-39 years
    Intervention: Other: Simulated heat wave
  • Older participants
    Individuals aged 65 years or older
    Intervention: Other: Simulated heat wave
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status Recruiting
Estimated Enrollment
 (submitted: September 2, 2020)
50
Original Estimated Enrollment Same as current
Estimated Study Completion Date August 31, 2024
Estimated Primary Completion Date August 31, 2022   (Final data collection date for primary outcome measure)
Eligibility Criteria

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
Sex/Gender
Sexes Eligible for Study: All
Ages 18 Years and older   (Adult, Older Adult)
Accepts Healthy Volunteers Yes
Contacts
Contact: Luke Belval, PhD 214-345-6503 LukeBelval@texashealth.org
Contact: Amy Slack-Bryant 214-345-8740 amybryant@texashealth.org
Listed Location Countries United States
Removed Location Countries  
 
Administrative Information
NCT Number NCT04538144
Other Study ID Numbers STU_2019_1759
Has Data Monitoring Committee No
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
IPD Sharing Statement Not Provided
Responsible Party Craig Crandall, University of Texas Southwestern Medical Center
Study Sponsor University of Texas Southwestern Medical Center
Collaborators Not Provided
Investigators Not Provided
PRS Account University of Texas Southwestern Medical Center
Verification Date February 2021