The Effects of N-acetylcysteine on Performance and Redox Homeostasis

NCT ID: NCT03121222

Last Updated: 2017-04-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 36 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-11-01
• Study Completion Date: 2016-09-12

Brief Summary

The main objective of the present study was to investigate whether N-acetylcysteine supplementation in individuals with low glutathione levels would confer ergogenic effects by replenishing glutathione levels and by reducing oxidative stress. Towards this aim, investigators sought to exploit the large inter-individual variability in redox biomarker levels. More specifically, investigators screened 100 male participants for glutathione baseline levels in blood and formed three stratified groups according to this value (i.e., low, moderate and high; 12 individuals per group). After by-passing the regression to the mean artefact by performing a second glutathione measurement in the three aforementioned groups, investigators assessed both aerobic and anaerobic physical performance in order to acquire a more comprehensive view about the ergogenic effectiveness of the antioxidant treatment. This was accomplished by implementing three different whole-body physical performance tests (i.e., VO2max test, time trial and Wingate), as opposed to most in vivo studies that either applied isolated body-part exercise tests (e.g., by isokinetic dynamometry) or performed a single exercise test (e.g., time-to-fatigue test). It was hypothesised, that data of the present investigation will bridge the chasm between the scientific (i.e., chronic antioxidant supplementation blunts exercise performance and adaptations) and the community-based (i.e., free radicals should anyway be counteracted by "protective" exogenous antioxidants) truths about the role of antioxidants as ergogenic aids. It was also hypothesised that the results will show that low glutathione levels are linked to decreased aerobic and anaerobic physical performance accompanied by increased levels of oxidative stress and that N-acetylcysteine supplementation will restore both performance and redox homeostasis. Based on the findings of the present investigation, the widespread routine practice of consuming antioxidants during exercise training could be changed and the consumption of antioxidants would be restricted only for those who are deficient in glutathione.

Conditions

Glutathione Metabolism Anemias

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SCREENING
• Blinding Strategy: SINGLE

Study Groups

Lactose

The placebo group received orally two lactose tablets per day for 30 days. Each individual received the capsules pre-packed in daily doses labeled with the day of consumption.

Group Type: PLACEBO_COMPARATOR

Lactose

Intervention Type: DRUG

The placebo group received orally two lactose tablets per day. The participants were instructed to receive the capsules every twelve hours. Each individual received the capsules pre-packed in daily doses labeled with the day of consumption. The supplementation period was 30-day for placebo.

N-acetylcysteine

The antioxidant group received orally two N-acetylcysteine tablets (each tablet contained 600 mg of NAC; Lamberts Health Care Ltd, Kent, United Kingdom). The participants were instructed to receive the capsules every twelve hours in order to achieve high concentration of N-acetylcysteine throughout the 24 h. Each individual received the capsules pre-packed in daily doses labeled with the day of consumption.

Group Type: EXPERIMENTAL

N-acetylcysteine

Intervention Type: DRUG

The antioxidant group received orally two N-acetylcysteine tablets (each tablet contained 600 mg of NAC; Lamberts Health Care Ltd, Kent, United Kingdom). The participants were instructed to receive the capsules every twelve hours in order to achieve high concentration of N-acetylcysteine throughout the 24 h. Each individual received the capsules pre-packed in daily doses labeled with the day of consumption. The supplementation period was 30-day for N-acetylcysteine.

Interventions

N-acetylcysteine

The antioxidant group received orally two N-acetylcysteine tablets (each tablet contained 600 mg of NAC; Lamberts Health Care Ltd, Kent, United Kingdom). The participants were instructed to receive the capsules every twelve hours in order to achieve high concentration of N-acetylcysteine throughout the 24 h. Each individual received the capsules pre-packed in daily doses labeled with the day of consumption. The supplementation period was 30-day for N-acetylcysteine.

Intervention Type: DRUG

Lactose

The placebo group received orally two lactose tablets per day. The participants were instructed to receive the capsules every twelve hours. Each individual received the capsules pre-packed in daily doses labeled with the day of consumption. The supplementation period was 30-day for placebo.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Healthy male subjects who participated recreationally in physical activities less than 3 times per week.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 29 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

National and Kapodistrian University of Athens

OTHER

Sponsor Role: collaborator

European University Cyprus

OTHER

Sponsor Role: collaborator

Aristotle University Of Thessaloniki

OTHER

Sponsor Role: lead

Responsible Party

Vassilis Paschalis

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Michalis Nikolaidis, PhD

Role: STUDY_DIRECTOR

Aristotle University Of Thessaloniki

Locations

European University Cyprus

Nicosia, , Cyprus

National and Kapodistrian University of Athens

Athens, , Greece

Aristotle University of Thessaloniki

Thessaloniki, , Greece

Countries

Cyprus; Greece

References

Margaritelis NV, Theodorou AA, Paschalis V, Veskoukis AS, Dipla K, Zafeiridis A, Panayiotou G, Vrabas IS, Kyparos A, Nikolaidis MG. Experimental verification of regression to the mean in redox biology: differential responses to exercise. Free Radic Res. 2016;50(11):1237-1244. doi: 10.1080/10715762.2016.1233330. Epub 2016 Oct 25.

Reference Type: BACKGROUND

PMID: 27596985 (View on PubMed)

Jeukendrup A, Saris WH, Brouns F, Kester AD. A new validated endurance performance test. Med Sci Sports Exerc. 1996 Feb;28(2):266-70. doi: 10.1097/00005768-199602000-00017.

Reference Type: BACKGROUND

PMID: 8775164 (View on PubMed)

Paschalis V, Theodorou AA, Kyparos A, Dipla K, Zafeiridis A, Panayiotou G, Vrabas IS, Nikolaidis MG. Low vitamin C values are linked with decreased physical performance and increased oxidative stress: reversal by vitamin C supplementation. Eur J Nutr. 2016 Feb;55(1):45-53. doi: 10.1007/s00394-014-0821-x. Epub 2014 Dec 20.

Reference Type: BACKGROUND

PMID: 25526969 (View on PubMed)

Nikolaidis MG, Kyparos A, Spanou C, Paschalis V, Theodorou AA, Panayiotou G, Grivas GV, Zafeiridis A, Dipla K, Vrabas IS. Aging is not a barrier to muscle and redox adaptations: applying the repeated eccentric exercise model. Exp Gerontol. 2013 Aug;48(8):734-43. doi: 10.1016/j.exger.2013.04.009. Epub 2013 Apr 28.

Reference Type: BACKGROUND

PMID: 23628501 (View on PubMed)

Other Identifiers

83022/2015

Identifier Type: -

Identifier Source: org_study_id