Genetic Risk Factor for Heat Stroke

Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18-60
SponsorUniversity of Iowa

About this trial

The goal of this observational study is to examine the effect of the Cystic Fibrosis (CF) Carrier state on the risk for dehydration and other CF-specific fluid-and-electrolyte disorders in male and female adults.

The primary aim of the study is to estimate the risk of electrolyte disorders attributable to the CF carrier state in a genotyped cohort.

This will be accomplished with two smaller projects- Aim 1 and Aim 2.

Aim 1 will consist of 100 CF Carriers and 100 age- and sex-matched controls. Participants in this aim will be asked to complete a Participant Info and Temperature Survey consisting of questions about race, ethnicity, medical history, and how they experience heat.

Aim 2 will consist of a subset of 25 CF Carriers and 25 age- and sex-matched controls from Aim 1. Participants in this aim will be scheduled for a visit to complete a heat challenge. At this visit, they will also complete the Participant Info and Temperature Survey. They will also sit in a sauna at 62 - 63 degrees Celsius for 45 minutes.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Previously genotyped as a CF carrier or control

Comfortable speaking/reading English

Disqualifiers

Previously genotyped as a CF patient

Diagnosis of Type 1 or Type 2 diabetes

History of heart attack, stroke, heart failure, or atherosclerosis

Currently pregnant

Trial population

Individuals who have previously been genotyped as CF Carriers or Controls.

Trial design

Design model

Case-control

Time perspective

Prospective

Treatments tested in this trial

  • Heat Challenge

    Procedure/Surgery

    Participants will be asked to arrive well-hydrated and to refrain from exercise, alcohol, caffeine, and smoking for 24 hours prior to the visit. Height, weight, blood pressure, and body fat percentage will be measured. Blood (15.5 ml) and urine will be collected. Participants will wear a heart rate monitor and sit in a heat chamber at 62-63 degrees Celsius for 45 minutes. Heart rate will be measured continuously. Body temperature and a self-report of their comfort (1-4 scale) and thermosensation (1-7 scale) will be measured before the challenge, every 15 minutes during the challenge, and after the challenge. During the challenge, a sample of sweat will be collected to measure electrolyte loss. Participants will consume 16 ounces of water at their own pace during the 45 minutes. If they become too uncomfortable to continue or their body temperature rises above 39 degrees Celsius, the challenge will be stopped. All baseline measures except body fat percentage will be measured again.

Treatment groups

200 Participants
are divided into 2 treatment groups
Group A: CF Carriers1 intervention
Group B: Controls1 intervention

Trial outcomes

Primary outcomes

1

Participant Scores for Temperature Sensitivity and Regulation Survey

Individual and composite scores for 5 components of the Temperature Sensitivity Survey (Heat- and Activity-Induced Autonomic Thermoregulation; Heat-Induced Behavioral Thermoregulation; Heat Perception; and Heat- and Activity-Induced Fatigue). For these 5 components, there are a total of 25 questions. All questions are on a 7-point scale, with the highest representing the most sensitive to heat and the lowest being the least sensitive. We will add up the scores for each question to arrive at a composite score for each component and the component scores will be added to arrive at a total score. Scores will be compared between groups.

Time frame
Baseline
2

Change in Weight

Weight will be measured in kilograms pre- and post-heat challenge. We will compare change in weight between groups.

Time frame
Up to 45 minutes
3

Change in Sodium Concentration

Sodium concentration will be measured pre- and post-heat challenge by blood draw and urine sample. Sodium concentration will be compared between groups.

Time frame
Up to 45 minutes
4

Change in Potassium Concentration

Potassium concentration will be measured pre- and post-heat challenge by blood draw and urine sample. Potassium concentration will be compared between groups.

Time frame
Up to 45 minutes

Secondary outcomes

Other outcomes

Sponsors and contacts

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