Exercise-induced oxidative stress and antioxidant enzyme activity in type 2 diabetic patients with and without diastolic dysfunction and hypertension

• Published in: Srpski arhiv za celokupno lekarstvo Vol. 137; no. 3-4; pp. 146 - 151
• Main Authors: Kostic, Nada, Caparevic, Zorica, Ilic, Sanja, Pencic, Biljana, Radojkovic, Jana, Marina, Djordje
• Format: Journal Article
• Language: English; Serbian
• Published: Serbia Serbian Medical Society 01.03.2009
• Subjects: antioxidant enzymes; Antioxidants - metabolism; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - enzymology; Diabetes Mellitus, Type 2 - metabolism; Diastole; diastolic dysfunction; exercise; Exercise Test; Female; Glutathione Peroxidase - blood; Humans; hypertension; Hypertension - complications; Male; Middle Aged; Oxidative Stress; Plasminogen Activator Inhibitor 1 - blood; Superoxide Dismutase - blood; type 2 diabetes mellitus; Ventricular Dysfunction, Left - complications
• ISSN: 0370-8179; 2406-0895
• DOI: 10.2298/SARH0904146K

Introduction. Antioxidant systems are important factors affecting the oxidation of lipoproteins and thereby the progression of atherosclerotic disease. It has been suggested that physical activity might maintain and promote the antioxidant defence capacity against the oxidative stress. Left ventricular dysfunction (LVDD) and hypertension are more common in subjects with diabetes mellitus (DM) type 2. Objective. To evaluate the oxidative stress in patients with DM type 2, particularly with LVDD and hypertension and to determine the influence of acute exercise training on the investigated parameters. Methods. To assess the oxidative stress of patients, we determined the following antioxidative parameters: triglycerides (TG), total cholesterol, low density cholesterol, OxLDL cholesterol, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), plasminogen activator-type 1 (PAI-1) which were measured at rest and immediately after the acute bout of the cardiopulmonary exercise cycle ergometer test. Results. In basal conditions, diabetic patients had a significant increase of TG (3.12?1.09 vs 1.74?0.9 mmol/l; p<0.01), OxLDL cholesterol (84.73?16.9 vs 79.00?29.26 mmol/l; p<0.05) and SOD enzyme activity (913.38?120.36 vs 877.14 ?153.18; p<0.05) compared to controls. During the acute exercise test, there were significantly greater levels of OxLDL (84.73?16.90 vs 92.33?23.29 mmol/l; p<0.05) in study patients. SOD significantly increased in both groups during exercise, in diabetic patients (913.38?120.36 vs 921.50?130.03 U/g Hb; p<0.05) and in controls (877.14?153.18 vs 895.00?193.49 U/g Hb; p<0.05). GSH-Px significantly increased only in diabetic patients after acute exercise (45.04?11.19 vs 51.81?15.07 U/g Hb; p<0.01), but not in controls. PAI significantly decreased during the exercise test only in healthy subjects (2.60?0.35 vs 2.22?0.65; p<0.05). Type 2 diabetic patients with cardiovascular complications (LVDD and hypertension) had a significant increase of GSH-Px activity (47.10?7.37 vs 54.52?11.97 U/g Hb; p<0.01). Conclusion. Elevated enzyme levels are associated with exercise in type 2 diabetic patients. We suggest that it could be a compensatory mechanism to prevent free radical tissue damage. We hypothesize that a physical training programme induces the enhancement of muscular and liver antioxidant enzymes and reduces the oxidative stress. Uvod. Oksidativni stres je vazan faktor koji utice na oksidaciju lipoproteina i napredovanje aterosklerotske bolesti, usled cega se istice i znacaj antioksidantnih mehanizama. Pretpostavlja se da fizicka aktivnost moze poboljsati odbrambene mehanizme protiv oksidativnog stresa. Disfunkcija leve komore i hipertenzija su mnogo cesce kod osoba obolelih od dijabetes melitusa tip 2 (DM tip 2). Cilj rada. Cilj rada je bio procena oksidativnog stresa kod bolesnika sa DM tip 2, posebno onih sa disfunkcijom leve komore i hipertenzijom, i odredjivanje uticaja intenzivnog vezbanja na vrednosti ispitivanih parametara. Metode rada. Da bi se procenio oksidativni stres ispitanika, mereni su nivoi: triglicerida, ukupnog holesterola, LDL-holesterola, oksidisanog LDL-holesterola (OxLDL), superoksid-dismutaze (SOD), glutation-peroksidaze (GSH-Px) i aktivatora plazminogena tip 1 (PAI-1). Svi pomenuti parametri mereni su u stanju mirovanja i neposredno po aerobnom vezbanju (ergometrijski test). Rezultati. U poredjenju sa ispitanicima kontrolne grupe, kod osoba sa DM tip 2 je tokom mirovanja uoceno znacajno povecanje nivoa triglicerida (3,12?1,09 prema 1,74?0,9 mmol/l; p<0,01), OxLDL (84,73?16,9 prema 79,00?29,26 mmol/l; p<0,05) i SOD (913,38?120,36 prema 877,14?143,18 mmol/l; p<0,05). Tokom vezbanja zabelezen je visi nivo OxLDL i kod bolesnika (84,73?16,90 prema 92,33?23,29 mmol/l; p<0,05) i kod ispitanika kontrolne grupe (79,00?29,26 prema 89,30?29,07 mmol/l; p<0,05). Nivo SOD je tokom vezbanja takodje bio znacajno veci i kod bolesnika (913,38?120,36 prema 921,50?130,03 U/g Hb; p<0,05) i kod ispitanika kontrolne grupe (877,14?153,18 prema 895,00?193,49 U/g Hb; p<0,05). Tokom vezbanja vrednosti GSH-Px su bile znacajno vece samo kod ispitanika sa DM tip 2 (45,04?11,19 prema 51,81?15,07 U/g Hb; p<0,01), dok se vrednost PAI-1 smanjivala samo kod zdravih ispitanika (2,60?0,35 prema 2,22?0,65; p<0,05). Kod bolesnika sa DM tip 2 i kardiovaskularnim komplikacijama (hipertenzijom i dijastolnom disfunkcijom leve komore) uoceno je znacajno povecanje samo aktivnosti GSH-Px (47,10?7,37 prema 54,52?11,97 U/g Hb; p<0,01). Zakljucak. Povecane vrednosti OxLDL, SOD i GSH-Px povezane su sa vezbanjem kod bolesnika sa DM tip 2. Vezbanje bi moglo biti kompenzatorni mehanizam kojim se sprecava ostecenje tkiva oslobodjenim slobodnim radikalima, sto dovodi do veceg oslobadjanja antioksidansa jetre i misica, cime se smanjuje oksidativni stres.