IJCS | Volume 31, Nº6, November / December 2018

DOI: 10.5935/2359-4802.20180058 610 ORIGINAL ARTICLE International Journal of Cardiovascular Sciences. 2018;31(6)610-618 Mailing Address: Elizabeth de Orleans Carvalho de Moura Universidade Federal de São Paulo - Campus Baixada Santista - Departamento de Biociências R. Silva Jardim, 136. Postal Code: 11015-020, Vl. Mathias, Santos, SP - Brazil E-mail: elizabeth.c.moura@hotmail.com Comparison betweent the Effects of Swimming and Treadmill-Based Aerobic Training Protocols in Diabetic Rats Elizabeth de Orleans Carvalho de Moura, 1 Kelvin Tanaka, 1 Moisés Felipe Pereira Gomes, 1 Evandro Nogueira, 2 Ricardo Gomes, 1 Debora Estadella, 1 Katt Mattos, 3 Patrícia Chakur Brum, 3 Alessandra Medeiros 1 Universidade Federal de São Paulo (UNIFESP), 1 São Paulo - Brazil Faculdade Integral Diferencial, 2 Piauí - Brazil Universidade de São Paulo (USP), 3 São Paulo - Brazil Manuscript received September 14, 2017, revised manuscript June 11, 2018, accepted June 18, 2018. Abstract Background: Type 1 diabetes mellitus (DM1) can cause damage to several physiological systems. Objectives: To compare and characterize the effects of aerobic exercise training (ET) performed by swimming with those of ET performed on a treadmill on the skeletal muscle and heart of rats with DM1. Methods: 41 male Wistar rats were randomized into four groups: nondiabetic control (CTR), diabetic control (DMC), diabetic trained on the treadmill (DMT), and diabetic trained by swimming (DMS). The trained groups performed aerobic exercise training for 8 weeks, 5 times a week, 60 min per day. Exercise tolerance, blood glucose, body weight, wet weight of the skeletal muscles and left ventricle (LV), muscle glycogen, cross-sectional area of skeletal muscles, and cross-sectional diameter and collagen volume fraction of the LV were evaluated. Results: The results were expressed as mean ± standard deviation of the mean and submitted to two-way ANOVA with post-hoc Bonferroni test. Aerobic ET protocols applied to animals with DM1, regardless of the ergometer, showed satisfactory results (p < 0.05) when compared to the control groups: improved exercise tolerance, increased glycogen content of the soleus and extensor digitorum longus (EDL) muscles and increased cross-sectional diameter of the left ventricular cardiomyocytes. In some variables, such as exercise tolerance and cross-sectional area of the soleus and EDL muscles, DMT showed better results than DMS (p < 0.05). On the other hand, DMS showed increased cross-sectional diameter of cardiomyocytes when compared with the DMT group. Conclusion: Both aerobic ET protocols offered benefits to animals with diabetes; however, due to the specific characteristics of each modality, different physiological adaptations were observed between the trained groups. (Int J Cardiovasc Sci. 2018;31(6)610-618) Keywords: Exercise; Physical Exertion; Rats, Wistar; Diabetes Mellitus; Exercise Test; Muscle, Skeletal. Introduction In Brazil, the current overall prevalence of diabetes mellitus (DM) is 7.6% and of these, 46% have not been diagnosed. 1 DM type 1 (DM1) is found in 5% to 10% of cases. This type is characterized by destruction of the insulin-secreting cells of the pancreas. 2 In the long term, DM1 can cause damage throughout the body and to several physiological systems, especially the kidneys, eyes, nerves, heart, and blood vessels. 3 Cardiomyocytes are greatly affected by the disease. The development of “diabetic cardiomyopathy 1” (DC) may occur 4 and skeletal muscle can also be affected. In fact, a reduction in the muscle fiber size occurs and in cases of poor glycemic control, there can also be alterations in the distribution of muscle fiber types. 5 Silva et al., 4 showed that ET performed in a swimming pool increased the amplitude of cardiomyocyte contraction in animals with DM1 and controls. On the