title: Effects of acute exercise on liver function and blood redox status in heavy drinkers.
abstract: Excessive alcohol consumption can induce oxidative stress, resulting in the development of several diseases. Exercise has been reported to prevent and/or improve a number of health issues through several mechanisms, including an improvement in redox status. It has also been previously suggested that exercise can help individuals with alcohol use disorders reduce their alcohol intake; however, research in this field is limited. The aim of the present study was to investigage the effects of acute exercise of moderate intensity on the liver function and blood redox status in heavy drinkers. For this purpose, a total of 17 heavy drinkers [age, 31.6±3.2 years; body mass index (BMI), 27.4±0.8 kg/m2; experimental group (EG)] and 17 controls [age, 33.5±1.3 years; BMI, 26.1±1.4 kg/m2; control group (CG), who did not exceed moderate alcohol consumption], underwent one trial of acute exercise of moderate intensity (50-60% of the heart rate reserve) for 30 min on a cycle ergometer, following an overnight fast, and abstaining from smoking and alcohol consumption. Blood samples were obtained before and immediately after exercise for later determination of the indices of liver function and blood redox status. The subjects in the EG had significantly higher (p<0.05) baseline γ-glutamyl transferase (γ-GT) levels compared to the subjects in the CG. Exercise thus resulted in significantly higher γ-GT levels (p<0.005) only in the EG. No significant differences in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) baseline levels were observed between the 2 groups. Following exercise, the AST levels increased significantly (p<0.001) in both groups, whereas the ALT levels increased significantly (p<0.01) only in the EG. The baseline glutathione (GSH) levels were significantly lower (p<0.05) and remained low following exercise in the EG. In addition, we observed a trend for higher (p=0.07) baseline levels of thiobarbituric acid-reactive substances (TBARS), which remained elevated post-exercise in the EG compared to the CG. Significantly increased post-exercise total antioxidant capacity (TAC; p<0.01) and uric acid (UA; p<0.05) levels were noted in the CG, whereas the TAC (p=0.06) and UA (p=0.08) levels increased and approached significance post-exercise in the EG. No significant differences in the baseline levels of total bilirubin and protein carbonyl were observed between the 2 groups, even post-exercise. Thus, the findings of the present study indicate that even though heavy drinkers may be prone to oxidative stress, their exercise-induced antioxidant response is similar to that of individuals who do not drink heavily.
authors.affiliation: Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece ; Department of Kinesiology, Institute for Research and Technology Thessaly, Karies, Trikala 42100, Greece.
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Georgakouli
authors.affiliation: Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece ; Department of Kinesiology, Institute for Research and Technology Thessaly, Karies, Trikala 42100, Greece.
authors.forename: Eirini
authors.initials: E
authors.lastname: Manthou
authors.affiliation: Department of Physical Education and Sport Science, Democritus University, Komotini 69100, Greece.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Fatouros
authors.affiliation: Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece ; Department of Kinesiology, Institute for Research and Technology Thessaly, Karies, Trikala 42100, Greece.
authors.forename: Chariklia K
authors.initials: CK
authors.lastname: Deli
authors.affiliation: Laboratory of Clinical Virology, University of Crete Medical School, Heraklion 71409, Greece.
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
authors.affiliation: Department of Forensic Sciences and Toxicology, Medical School, University of Crete, Heraklion 71003, Greece.
authors.forename: Aristidis M
authors.initials: AM
authors.lastname: Tsatsakis
authors.affiliation: Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41221, Greece.
authors.forename: Demetrios
authors.initials: D
authors.lastname: Kouretas
authors.affiliation: Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece ; Department of Kinesiology, Institute for Research and Technology Thessaly, Karies, Trikala 42100, Greece ; School of Sports, Performing Arts and Leisure, University of Wolverhampton, Walsall, West Midlands WS1 3BD, UK.
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Koutedakis
authors.affiliation: Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece.
authors.forename: Yannis
authors.initials: Y
authors.lastname: Theodorakis
authors.affiliation: Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala 42100, Greece ; Department of Kinesiology, Institute for Research and Technology Thessaly, Karies, Trikala 42100, Greece.
authors.forename: Athanasios Z
authors.initials: AZ
authors.lastname: Jamurtas
keywords: alcohol; alcoholism; antioxidants; excessive alcohol consumption; oxidative stress; training