Comparing Exertional Heat Illness Risk Factors Between Patients and Controls

NCT ID: NCT05303142

Last Updated: 2023-05-22

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 95 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2022-02-01
• Study Completion Date: 2023-03-06

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.

Conditions

Exertional Heat Illness

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Individuals with a history of EHI

Service personnel who have a history of EHI.

Heat Tolerance Assessment

Intervention Type: OTHER

60-90 minutes exercise in hot (34 °C; 45% R.H.) conditions at 60%VO2max

Control participants without a history of EHI

Matched control participants with no history of EHI. They will be matched to the experimental group for parameters that are known to influence thermoregulatory responses to exercise heat-stress.

1. Relative aerobic fitness (V̇O2max; ml∙kg-1∙min-1)

2. Body mass (kg)

3. Body surface area (m2)

4. Age

5. Sex

Heat Tolerance Assessment

Intervention Type: OTHER

60-90 minutes exercise in hot (34 °C; 45% R.H.) conditions at 60%VO2max

Interventions

Heat Tolerance Assessment

60-90 minutes exercise in hot (34 °C; 45% R.H.) conditions at 60%VO2max

Intervention Type: OTHER

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Liverpool John Moores University

OTHER

Sponsor Role: collaborator

Institute of Naval Medicine (UK)

UNKNOWN

Sponsor Role: collaborator

Headquarters Army Recruiting and Initial Training Command (UK)

UNKNOWN

Sponsor Role: collaborator

Public Health Wales

OTHER_GOV

Sponsor Role: collaborator

University of Portsmouth

OTHER

Sponsor Role: lead

Responsible Party

Jo Corbett

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

University of Portsmouth

Portsmouth, Hampshire, United Kingdom

Countries

United Kingdom

Other Identifiers

209321

Identifier Type: -

Identifier Source: org_study_id