Clinical trial NCT04593316: Study of Risk Factors for the Occurrence and Severity of Exertional Heatstroke in the Military Environment
Official title: Study of Risk Factors for the Occurrence and Severity of Exertional Heatstroke in the Military Environment
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Heat Stroke
Lead sponsor: Direction Centrale du Service de Santé des Armées
Sponsor class: OTHER
First posted: 2020-10-20
Enrollment: 300
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The study population will be composed of patients who are experiencing or who have experienced exertional heatstroke (heatstroke group) and people who have not (control group).

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: Difference of the frequency of CYP24A1 gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of DRD2 gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of BDNF gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of COMT gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of FAAH gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of TPH2 gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of GRIN2B gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of PER3 gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of TNF-a gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of IL-6 gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of IL1B gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of HSPA1B gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
measure: Difference of the frequency of TLR4 gene polymorphisms between the heatstroke group and the control group
timeFrame: At enrollment (day 1)
Secondary outcomes:
Other outcomes:
Locations:
city: Brétigny-sur-Orge
country: France
facility: Institut de Recherche Biomédicale des Armées
city: Marseille
country: France
facility: Hôpital d'Instruction des Armées Laveran
city: Paris
country: France
facility: Ecole du Val-de-Grâce
Study officials:
References: