Study of Risk Factors for the Occurrence and Severity of Exertional Heatstroke in the Military Environment (EXPLO-CCE)

Direction Centrale du Service de Santé des Armées

Status: Enrolling

Conditions: Heat Stroke

Treatments: Other: Heart rate monitoring; Other: Core temperature monitoring; Behavioral: Questionnaires; Other: Ingestible core temperature capsule intake; Other: Saliva collection; Other: Physical exercise

Study type: Observational

Funder types: Other

Identifiers

NCT04593316

2019PBMD03

2020-A01967-32 (Other Identifier)

Details and patient eligibility

About

Although the circumstances of onset and management of exertional heatstroke have been identified for several years, its pathophysiology remains imperfectly understood. Exertional heatstroke is the result of both extrinsic (i.e. environmental) and intrinsic (i.e. individual) contributing factors.

Extrinsic factors are well known (high ambient temperature and hygrometry, poorly "breathable" clothing, intense and prolonged physical effort) but some of them may be observed in milder conditions. In the French Armed Forces, 25% of the exertional heatstrokes that have been reported between 2005 and 2011 occurred below 17°C.

Intrinsic factors, on the other hand, are numerous and less consensual, partly because of the imperfect knowledge of exertional heatstroke physiopathology. Potential factors include a thermoregulatory defect (inability to maintain a temperature plateau during an effort) and several genetic mutations may also contribute to explain a propensity to present an exertional heatstroke. While exertional heatstroke is clearly not a monogenic pathology, the association of several polymorphisms could contribute to this vulnerability. Among the genes that have been explored, mutations in ryanodine receptor type 1 (RyR 1), calsequestrin-1 or angiotensin-1 converting enzyme (ACE) appear to be potential candidates. However, it is very likely that other polymorphisms may be involved, such as: genes involved in sports performance and exercise rhabdomyolysis, in the inflammatory cascade, permeability of the digestive epithelial barrier, adenosine receptors and susceptibility to anxiety.

Finally, motivation is a mixed factor often claimed to be involved in exertional heatstroke but has never been quantified and needs to be objectified.

To date, none of these hypotheses has been clearly assessed by comparing patients who experienced exertional heatstroke to healthy subjects.

Enrollment: 300 estimated patients

Sex: All

Ages: 18 to 45 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Active military
• Between 18 and 45 years old
• Ability to the walk/run test

Exclusion criteria

• Ongoing drug treatment (for the control group only),
• BMI greater than or equal to 30,
• Contraindication to the ingestion of a core temperature capsule

Trial design

300 participants in 2 patient groups

Exertional heatstroke group

Description:

Patients presenting or having presented exertional heatstroke.

Treatment:

Other: Ingestible core temperature capsule intake

Behavioral: Questionnaires

Other: Saliva collection

Other: Core temperature monitoring

Other: Physical exercise

Other: Heart rate monitoring

Control group

Description:

Healthy people who never experienced exertional heatstroke.

Treatment:

Other: Ingestible core temperature capsule intake

Behavioral: Questionnaires

Other: Saliva collection

Other: Core temperature monitoring

Other: Physical exercise

Other: Heart rate monitoring