Assessment of the Impact of N-acetylcysteine Supplementation on Physical Performance

Study Overview
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Brief Summary
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Study aims to verify the hypothesis: N-acetylcysteine (NAC) supplementation improves exercise capacity in people training endurance sports and the effectiveness of this supplementation depends on the polymorphism of genes related to folate and glutathione metabolism. NAC supplementation affects the parameters of oxidative stress among women and men training endurance disciplines

Detailed Description
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Glutathione depletion caused by a combination of intense physical exertion associated with the generation of significant amounts of reactive oxygen species (ROS), and possibly with having an unfavorable variant of the methylenetetrahydrofolate reductase (MTHFR), glutamate-cysteine ligase catalytic subunit (GCLC); glutamate-cysteine ligase modifier subunit (GCLM); glutathione S-transferase Pi 1 (GSTP1); glutathione synthetase (GSS) or cystathionine-β-synthase (CBS) genes may contribute to lower adaptation to exercise, but also to deterioration of health of people training endurance sports. The main objective of the study is to verify the hypothesis that NAC supplementation has a beneficial effect on regeneration between intense exercise tests simulating a race characteristic for a given discipline. In addition, this study is aimed at checking whether genotype may modify the effectiveness of the supplementation measured as exercise and biochemical parameters . A double-blind study involving 100 women and men supplementing 1200 mg of N-acetylcysteine daily or 1200 mg of maltodextrin in three equal doses. Supplementation will last for 7 days. Blood sampling and body composition testing will be performed in the morning of the exercise test day. Discipline-specific exercise testing will be performed before and after the intervention.

Official Title
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Assessment of the Impact of N-acetylcysteine Supplementation on Physical Performance Depending on the Polymorphism of Genes Related to Folate Metabolism

Conditions
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Skeletal Muscle Performance, Gene Polymorphisms

Intervention / Treatment
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* Dietary Supplement: N-acetylcysteine
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consent to participate in the study and acceptance of the established scheme for conducting the intervention age range between 18 and 45 years old regular training with a frequency of at least 4 times a week during the last year, Exclusion Criteria: no consent to participate in the study and no acceptance of the established scheme of the conducted intervention existing diseases of the blood system and neoplastic diseases respiratory system diseases obesity any medical contraindications to exercise Results obtained from exercise tests that do not meet the inclusion criteria use of NAC during the last month allergy to NAC smoking pregnancy and lactation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Eligible volunteers will be randomly assigned to one of the research groups. One of the groups will be taking the supplement for a period of 7 days, while the other group will be taking a placebo. Then a 3 week washout period will be performed. After that the groups will be exchanged and each participant will be assigned to a different group than it was in the first period of the study.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: N-acetylcysteine<br>Intervention: Dietary Supplement: N-acetylcysteine Participants will undergo two exercise tests and daily supplementation with N-acetylcysteine orally in three doses a day for seven consecutive days. | Dietary Supplement: N-acetylcysteine<br>* 100 women and men supplementing 1200 mg of N-acetylcysteine daily in three equal doses. Supplementation will last for 7 days.<br>|
| Placebo Comparator: Placebo<br>Supplement: Placebo Participants will undergo two exercise tests and daily supplementation with placebo orally in three doses a day for seven consecutive days. | Dietary Supplement: Placebo<br>* 100 women and men supplementing 1200 mg of placebo daily in three equal doses. Supplementation will last for 7 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assesment of change in results of time trial test | (min/test) change within groups and between groups | Baseline,1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduced glutathione (GSH) | GSH (µM) concentrations change within the group and between the groups | Baseline,1 week | 
| Oxidized glutathione (GSSG) | GSSG (µM) concentrations change within the group and between the groups | Baseline,1 week | 
| Homocysteine (Hcy) | Hcy (µmol/l) concentrations change within the group and between the groups | Baseline,1 week | 
| Total cholesterol (TChol) | TChol (mg/dl) concentrations change within the group and between the groups | Baseline,1 week | 
| Blood HDL-cholesterol (HDL-C) | HDL-C (mg/dl) concentrations change within the group and between the groups | Baseline,1 week | 
| Blood LDL-cholesterol (LDL-C) | LDL-C (mg/dl) concentrations change within the group and between the groups | 1 week | 
| Blood triacylglycerol (TAG) | TAG (mg/dl) concentrations change within the group and between the groups | Baseline,1 week | 
| Dietary intake | macro and micronutrient intake (g,mg,ug) | Baseline,1 week | 
| aspartate aminotransferase (ASPAT) | ASPAT [U/l] Changes within groups and between groups | 1 week | 
| Alanine transaminase (ALAT) | ALAT [U/l] change within groups and between groups | Baseline,1 week | 
| Oxygen volume (VO2) | VO2 (ml/kg bw./min) change within groups and between groups | Baseline,1 week | 
| Carbon dioxide volume (VCO2) | VCO2 (ml/kgm.c./min) change within groups and between groups | Baseline,1 week | 
| Testosterone (T) | T (ng/dL) concentrations change within the group and between the groups | Baseline,1 week | 
| Cortisol (C) | C (ng/dL) concentrations change within the group and between the groups | Baseline,1 week | 
| Body mass(BM) | Change in BM (kg) within groups and between groups | Baseline, 1 week | 
| Fat Free Mass (FFM) | FFM change within (kg) groups and between groups | Baseline, 1 week | 
| Fat Mass% (FM%) | FM% change within groups and between groups | Baseline, 1 week | 
| Thiobarbituric Acid Reactive Species (TBARS) | TBARS concentrations change within the group and between the groups | 1 week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sport performance, gene polymorphism, N-acetylcysteine