Contents lists available at ScienceDirect Obesity Medicine journal homepage: www.elsevier.com/locate/obmed Original research Periodized exercise performed in aquatic or dry land environments improves circulating reactive species and 8-isoprostane levels without any impact on total antioxidant capacity in patients with type 2 diabetes mellitus Arthiese Korb a , Laura Reck Cechinel b , Karine Bertoldi b , Rodrigo Sudatti Delevatti c , Felipe dos Santos Moysés b , Carla Basso b , Luis Fernando Martins Kruel c , Ionara Rodrigues Siqueira a,b,* a Programa de Pós-Graduação em Medicina: Ciências Médicas, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Brazil b Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil c Programa de Pós-Graduação em Ciência do Movimento Humano, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil ARTICLE INFO Keywords: Type 2 diabetes Periodized exercise Aquatic environment Land environment Reactive species 8-Isoprostane Oxidative status ABSTRACT Aims: The aim was to compare the impact of acute exercise and periodized training performed in aquatic and dry land environments on oxidative status, evaluating reactive species levels, macromolecules damage and antioxidant defense systems in diabetes mellitus type 2 (T2DM) patients. Methods: Twelve weeks of individualized exercise including walking or running in a swimming pool (aquatic group) or in a track (dry land group) were performed. Blood samples were collected before and after the first and last exercise sessions. Reactive species content, lipid peroxidation (8-isoprostane and water-soluble fluorescent substances), and protein oxidative damage were quantified in plasma, while total antioxidant potential and antioxidant enzyme activities, specifically superoxide dismutase, catalase and glutathione peroxidase, were evaluated in erythrocytes. Results: Periodized aerobic exercise performed in both environments acutely reduced reactive species and 8- isoprostane levels in sedentary conditions (after first session) and after 12 weeks of training (after last session) in T2DM patients. In addition, our exercise protocol performed in both environments reduced antioxidant enzymes activities; however total antioxidant capacity was unchanged. Conclusions: Our results suggest that periodized training in both aquatic and land environments improves acutely circulating oxidative stress, specifically reactive species and 8-isoprostane levels, without any effect on total antioxidant capacity, in sedentary and trained T2DM patients. 1. Introduction Exercise has been widely considered as a non-pharmacological ap- proach to prevent and treat diabetes mellitus type 2 (T2DM) reducing morbidity and health-care costs (Warburton et al., 2006; Newsholme et al., 2009; Colberg et al., 2010), however little is known about the training frequency, mode and intensity that are needed to optimize the outcomes. Besides, there are few studies investigating the impact of periodized training protocols, which are characterized by increases in intensity over time considering individual performance in T2DM. Previously, our group demonstrated that periodized training per- formed in both water and dry land has positive effect in T2DM, since it was able to improve plasma glucose control and reduced cardiometa- bolic risk factors; specifically decreased glycated hemoglobin (HbA1c), total cholesterol, low-density lipoprotein (LDL) cholesterol, plasma angiotensin (ANG) II and C-reactive protein (CRP) levels were found (Delevatti et al., 2016). In addition, acute and periodized exercise in both environments impacts similarly circulating epigenetic and in- flammatory parameters, respectively, histone desacetilase activity and Interleukin-10 (IL-10) levels, an anti-inflammatory cytokine (Korb et al., 2018). Although several studies have demonstrated the relationship be- tween diabetes-induced hyperglycemia and redox imbalance, as well as it has been suggested that antioxidant and pro-oxidant machineries are https://doi.org/10.1016/j.obmed.2019.100102 Received 18 October 2018; Received in revised form 24 April 2019; Accepted 18 May 2019 * Corresponding author. Laboratório de Neuropsicofarmacologia, Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite, 500, CEP 90050-170, Porto Alegre, RS, Brazil. E-mail address: ionara@ufrgs.br (I.R. Siqueira). Obesity Medicine 14 (2019) 100102 2451-8476/ © 2019 Published by Elsevier Ltd. T