Contribution of L-Tyrosine to Recovery From Operational Strain on Return From External Operation

Study Overview
=================
Brief Summary
-----------------
Operational conditions amplify soldier's constraints and stress factors, upsetting individual and collective adaptive landmarks. The soldier's resistance is strained by the high intensity of stressors, by the long duration of exposure and by their cumulative effect. This may lead to a state of operational strain that refers to chronic stress and the allostatic load imposed by operational constraint. The investigators believe that operational strain could manifest itself by a kind of accelerated aging of the organism due to the increased allostatic load without sufficient resource restoration (neurotransmitter precursors, partial and repeated sleep deprivation, etc.). This aging mechanism would be reversible after a sufficient period of resource restoration (sleep, physical activity, adapted diet, etc.).

Official Title
-----------------
Contribution of L-Tyrosine to Recovery From Operational Strain on Return From External Operation

Conditions
-----------------
Stress, Psychological

Intervention / Treatment
-----------------
* Biological: Blood collection
* Drug: L-Tyrosine 500 Mg
* Behavioral: Psychological questionnaires
* Device: Photoplethysmography
* Drug: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: From 18 to 65 years of age Exclusion Criteria: Tyrosine intake within the previous 15 days History of neurological or psychiatric disorder History of nephrological or endocrine disorder or liver failure Hereditary tyrosinemia

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study is composed of 2 groups, each of which is composed of 2 arms: External Operation group L-Tyrosine arm Placebo arm Rear Base group L-Tyrosine arm Placebo arm
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tyrosine - External Operation<br>1-month L-Tyrosine treatment following 4-month external operation | Biological: Blood collection<br>* A blood sample will be collected before during and after the treatment.<br>Drug: L-Tyrosine 500 Mg<br>* The participants will be administered 4 capsules of L-Tyrosine 500 mg per oral route daily over 1 month.<br>Behavioral: Psychological questionnaires<br>* The participants will fill in several psychological questionnaires before, during and after treatment administration: Life Event Checklist Moral injury Posttraumatic Checklist Burnout Assessment Tool State-Trait Anger Expression Inventory-2 Ruminative Response Scale - Reconsidered Deployment Risk and Resilience Inventory-2 Questionnaire about tobacco use<br>Device: Photoplethysmography<br>* Photoplethysmography recording will be performed before during and after the treatment.<br>|
| Experimental: Placebo - External Operation<br>1-month Placebo treatment following 4-month external operation | Biological: Blood collection<br>* A blood sample will be collected before during and after the treatment.<br>Behavioral: Psychological questionnaires<br>* The participants will fill in several psychological questionnaires before, during and after treatment administration: Life Event Checklist Moral injury Posttraumatic Checklist Burnout Assessment Tool State-Trait Anger Expression Inventory-2 Ruminative Response Scale - Reconsidered Deployment Risk and Resilience Inventory-2 Questionnaire about tobacco use<br>Device: Photoplethysmography<br>* Photoplethysmography recording will be performed before during and after the treatment.<br>Drug: Placebo<br>* The participants will be administered 4 capsules of Lactose 500 mg (placebo) per oral route daily over 1 month.<br>|
| Experimental: Tyrosine - Rear Base<br>1-month L-Tyrosine treatment following 4 months at rear base | Biological: Blood collection<br>* A blood sample will be collected before during and after the treatment.<br>Drug: L-Tyrosine 500 Mg<br>* The participants will be administered 4 capsules of L-Tyrosine 500 mg per oral route daily over 1 month.<br>Behavioral: Psychological questionnaires<br>* The participants will fill in several psychological questionnaires before, during and after treatment administration: Life Event Checklist Moral injury Posttraumatic Checklist Burnout Assessment Tool State-Trait Anger Expression Inventory-2 Ruminative Response Scale - Reconsidered Deployment Risk and Resilience Inventory-2 Questionnaire about tobacco use<br>Device: Photoplethysmography<br>* Photoplethysmography recording will be performed before during and after the treatment.<br>|
| Experimental: Placebo - Rear Base<br>1-month Placebo treatment following 4 months at rear base | Biological: Blood collection<br>* A blood sample will be collected before during and after the treatment.<br>Behavioral: Psychological questionnaires<br>* The participants will fill in several psychological questionnaires before, during and after treatment administration: Life Event Checklist Moral injury Posttraumatic Checklist Burnout Assessment Tool State-Trait Anger Expression Inventory-2 Ruminative Response Scale - Reconsidered Deployment Risk and Resilience Inventory-2 Questionnaire about tobacco use<br>Device: Photoplethysmography<br>* Photoplethysmography recording will be performed before during and after the treatment.<br>Drug: Placebo<br>* The participants will be administered 4 capsules of Lactose 500 mg (placebo) per oral route daily over 1 month.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference between the change in Burnout Assessment Tool (BAT) score following 1-month treatment in each arm | The Burnout Assessment Tool (BAT) is used to assess burn-out risk. The score ranges from 1 to 5, with higher scores indicating a higher risk of burn-out. | After 1-month treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference between the change in catecholamine level following 1-month treatment in each arm | Catecholamine level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 
| Difference between the change in aminoacid level following 1-month treatment in each arm | Aminoacid level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 
| Difference between the change in zonulin level following 1-month treatment in each arm | Zonulin level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 
| Difference between the change in Brain-Derived Neurotrophic Factor (BDNF) level following 1-month treatment in each arm | BDNF level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 
| Difference between the change in gamma-aminobutyric acid (GABA) level following 1-month treatment in each arm | GABA level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 
| Difference between the change in Tumor Necrosis Factor Alpha (TNFα) level following 1-month treatment in each arm | TNFα level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 
| Difference between the change in Interleukin-6 (IL6) level following 1-month treatment in each arm | IL6 level will be measured in blood before during and after 1-month treatment. | After 1-month treatment | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
L-tyrosine