Carrier State, Dehydration, Heat Stroke
Conditions
Brief summary
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.
Interventions
PROCEDUREHeat Challenge
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.
Sponsors
University of Iowa
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Previously genotyped as a CF carrier or control * Comfortable speaking/reading English
Exclusion criteria
* 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 * Currently taking beta blockers or diuretics * Prisoner status * Unable to provide own written informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Participant Scores for Temperature Sensitivity and Regulation Survey | Baseline | 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. |
| Change in Weight | Up to 45 minutes | Weight will be measured in kilograms pre- and post-heat challenge. We will compare change in weight between groups. |
| Change in Sodium Concentration | Up to 45 minutes | Sodium concentration will be measured pre- and post-heat challenge by blood draw and urine sample. Sodium concentration will be compared between groups. |
| Change in Potassium Concentration | Up to 45 minutes | Potassium concentration will be measured pre- and post-heat challenge by blood draw and urine sample. Potassium concentration will be compared between groups. |
| Concentration of Sweat Chloride | Up to 45 minutes | Sweat chloride will be measured pre- and post-heat challenge by sweat collection. Sweat chloride will be compared between groups. |
| Final Score on Comfort Scale | Up to 45 minutes | Participants will rate their level of comfort on a scale of 1-4 at the end of the heat challenge. Scores will be compared between groups. |
| Final Score on Thermosensation Scale | Up to 45 minutes | Participants will rate their level of thermosensation on a scale of 1-7 at the end of the heat challenge. Scores will be compared between groups. |
Countries
United States
Contacts
CONTACTAaron Miller, PhD
CONTACTShelby L Francis, PhD
PRINCIPAL_INVESTIGATORAaron Miller, PhD
University of Iowa
Outcome results
None listed