Clinical trial NCT05303142: Comparing Exertional Heat Illness Risk Factors Between Patients and Controls
Official title: Comparison of Novel Putative Risk Factors for Exertional Heat Illness Between a Military Patient Cohort and Matched Control Cohort During Exercise Heat Stress
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Exertional Heat Illness
Lead sponsor: University of Portsmouth
Sponsor class: OTHER
Collaborators: name: Liverpool John Moores University
name: Institute of Naval Medicine (UK)
name: Headquarters Army Recruiting and Initial Training Command (UK)
name: Public Health Wales
First posted: 2022-03-31
Enrollment: 95
Sex: ALL
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Individuals who have experienced a recent exertional heat illness and matched controls with no previous history of exertional heat illness

Brief summary: The arduous nature of military training and operations require personnel to encounter high heat load, e.g., during intense physical exertion, particularly in the heat. These conditions reduce operational effectiveness and expose personnel to a risk of incapacitation and death from exertional heat illness (EHI). The primary aim of this study is to compare putative 'chronic' EHI risk factors between a cohort who have suffered a history of EHI and a control cohort with no EHI history. The secondary aim is to examine the influence of these EHI risk factors on thermoregulation during a standard heat tolerance assessment.

Detailed description: Military training and operations present a risk of incapacitation and death from Exertional Heat Illness (EHI). However, widely accepted EHI risk factors are absent in almost half of all United Kingdom (UK) military EHI cases, indicating that a significant number of EHI cases in military personnel involve alternative risk factors. Risk factors for EHI can been classified along a spectrum ranging from acute (e.g. recent poor sleep) to chronic (e.g. low fitness), with the role of chronic risk factors supported by the observation that individuals who have suffered an EHI are at a substantially increased risk of subsequent EHI. The primary aim of this study is to compare putative 'chronic' EHI risk factors (e.g. composition of gastrointestinal (GI) microbiome, infection and inflammation, trait-like psychological factors) between a cohort who have suffered a history of EHI and a control cohort with no EHI history. The secondary aim is to examine the influence of these EHI risk factors on thermoregulation during a standard heat tolerance assessment.

Eligibility criteria: Inclusion Criteria:

Individuals with a history of EHI:

* Previous EHI episode
* Normal resting ECG
* Male or female
* 18 - 40 years

Control participants:

* No previous history of EHI
* Normal resting ECG
* Male or female
* 18 - 40 years

Primary outcomes:
measure: Core temperature
timeFrame: At 60 minutes (or test termination if earlier) of Heat Tolerance Assessment
measure: Core temperature
timeFrame: Rate of rise from 30 to 60 minutes (or test termination if earlier) of Heat Tolerance Assessment
measure: Diversity of gastrointestinal microbiota
timeFrame: Baseline
measure: Diversity of gastrointestinal microbiota
timeFrame: Baseline
measure: Abundance of gastrointestinal microbiota
timeFrame: Baseline
measure: Detection of sexually transmitted pathogens
timeFrame: Baseline
measure: Detection of respiratory pathogens
timeFrame: Baseline
measure: Detection of gastrointestinal pathogens
timeFrame: Baseline
measure: Circulating Interleukin 6
timeFrame: Baseline
measure: Circulating Interleukin 6
timeFrame: Post Heat Tolerance Assessment (within 15 minutes of test end)
measure: Circulating C-Reactive Protein
timeFrame: Baseline
measure: Circulating C-Reactive Protein
timeFrame: Post Heat Tolerance Assessment (within 15 minutes of test end)
measure: Circulating Claudin 3
timeFrame: Baseline
measure: Circulating Claudin 3
timeFrame: Post Heat Tolerance Assessment (within 15 minutes of test end)
measure: Circulating Zonulin
timeFrame: Baseline
measure: Circulating lipopolysaccharide binding protein
timeFrame: Baseline
measure: Circulating lipopolysaccharide binding protein
timeFrame: Post Heat Tolerance Assessment (within 15 minutes of test end)
measure: Circulating intestinal fatty acid binding protein
timeFrame: Baseline
measure: Circulating intestinal fatty acid binding protein
timeFrame: Post Heat Tolerance Assessment (within 15 minutes of test end)
measure: Gastrointestinal illness symptomology questionnaire
timeFrame: Baseline
measure: Gastrointestinal illness symptomology questionnaire
timeFrame: Pre Heat Tolerance Assessment
measure: Gastrointestinal illness symptomology questionnaire
timeFrame: Immediately post Heat Tolerance Assessment
measure: Respiratory illness symptomology, measured by Jackson common cold questionnaire
timeFrame: Baseline
measure: Sleep quality and quantity, measured by Pittsburgh Sleep Quality Index
timeFrame: Baseline -3 days
measure: Motivation, measured by Motivation scale
timeFrame: Baseline -3 days
measure: State-trait anxiety, measured by state-trait anxiety inventory form Y-2
timeFrame: Baseline -3 days
measure: Risk taking, measured by the risk-taking inventory
timeFrame: Baseline -3 days
measure: Resilience, measured by the Connor-Davidson resilience scale
timeFrame: Baseline -3 days
measure: Stress, measured by perceived stress scale
timeFrame: Baseline -3 days
measure: Mental readiness
timeFrame: Baseline
measure: Stress
timeFrame: Baseline
Secondary outcomes:
measure: Heat rate
timeFrame: At 5 minute intervals during the Heat Tolerance Assessment
measure: Thermal comfort
timeFrame: At 15 minute intervals during Heat Tolerance Assessment
measure: Thermal sensation
timeFrame: At 15 minute intervals during Heat Tolerance Assessment
measure: Rating of Perceived Exertion
timeFrame: At 15 minute intervals during Heat Tolerance Assessment
measure: Skin Temperature
timeFrame: During Heat Tolerance Assessment
measure: Sweat rate
timeFrame: During Heat Tolerance Assessment
Other outcomes:
measure: Body mass
timeFrame: Baseline
measure: Relative maximal aerobic fitness
timeFrame: Baseline
measure: Urine osmolality
timeFrame: Baseline
Locations:
city: Portsmouth
country: United Kingdom
facility: University of Portsmouth
state: Hampshire
Study officials:
References: