Effects of l-arginine supplementation on blood flow, oxidative stress status and exercise responses in young adults with uncomplicated type I diabetes

• Autor(a) principal: Fayh, Ana Paula Trussardi
• Data de Publicação: 2013
• Outros Autores: Krause, Mauricio, Rodrigues-Krause, Josianne, Ribeiro, Jerri Luiz, Ribeiro, Jorge Pinto, Friedman, Rogério, Moreira, José Cláudio Fonseca, Reischak-Oliveira, Alvaro
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/55963; https://doi.org/10.1007/s00394-012-0404-7
• topic: L-Arginine; type 1 diabetes; blood flow; oxidative stress

Background and aims: Vascular disease is the principal cause of death and disability in patients with diabetes, and endothelial dysfunction seems to be the major cause in its pathogenesis. Since L-arginine levels are diminished in conditions such as type 1 and type 2 diabetes, in this work we aimed to verify the effects of L-arginine supplementation (7 g/day) over the endothelial function and oxidative stress markers in young male adults with uncomplicated type 1 diabetes. We also investigated the influences of L-arginine administration on vascular/oxidative stress responses to an acute bout of exercise. Methods: Ten young adult male subjects with uncomplicated type 1 diabetes and twenty matched controls volunteered for this study. We analysed the influence of L-arginine supplementation (7 g/day during 1 week) over lower limb blood flow (using a venous occlusion plethysmography technique), oxidative stress marker (TBARS, Carbonyls), anti-oxidant parameters (uric acid and TRAP) and total tNOx in rest conditions and after a single bout of submaximal exercise (VO2 at 10 % below the second ventilatory threshold). Data described as mean ± standard error (SE). Alpha level was P < 0.05. Results: Glycaemic control parameters were altered in type 1 diabetic subjects, such as HbA1c (5.5 ± 0.03 vs. 8.3 ± 0.4 %) and fasted glycaemia (94.8 ± 1.4 vs. 183 ± 19 mg/dL). Oxidative stress/damage markers (carbonyls and TBARS) were increased in the diabetic group, while uric acid was decreased. Rest lower limb blood flow was lower in type 1 diabetic subjects than in healthy controls (3.53 ± 0.35 vs. 2.66 ± 0.3 ml 100 ml−¹ min−¹). L-Arginine supplementation completely recovered basal blood flow to normal levels in type 1 diabetics’ subjects (2.66 ± 0.3 to 4.74 ± 0.86 ml 100 ml−¹ min−¹) but did not interfere in any parameter of redox state or exercise. Conclusion: Our findings highlight the importance of L-arginine for the improvement of vascular function in subjects with diabetes, indicating that L-arginine supplementation could be an essential tool for the treatment for the disease complications, at least in non-complicated diabetes. However, based on our data, it is not possible to draw conclusions regarding the mechanisms by which L-arginine therapy is inducing improvements on cardiovascular function, but this important issue requires further investigations