The effect of high intensity physical exercise and hypoxia on glycemia, angiogenic biomarkers and cardiorespiratory function in patients with type 1 diabetes

Background. An integral part of the treatment of diabetes is physical activity. Scientific reports have shown the beneficial effects of hypoxia and exercise on cardiovascular and metabolic variables in patients with diabetes. Objectives. The aim of the study was to assess the effect of normobaric hypoxia and exercise on the serum concentrations of proangiogenic factors and glycemia in patients with type 1 diabetes. Material and methods. A total of 28 adults (aged 30.4 years +/- 9.7 years), suffering from diabetes for 12.1 years +/- 6.0 years and healthy individuals, participated in the following trials: normoxic (Nor) and hypoxic (Hy) rest and Nor and Hy incremental exercise test (Ex) (FIO2 = 15.2%). The Altitude Trainer Hypoxico System (HYP-123 Hypoxic Generator, LOWOXYGEN Technology GmbH, Berlin, Germany) corresponding to a height of about 2500 m above sea level was used in the study. Exercise tests were performed on a cycle ergometer Excalibur Sport (Lode B.V., Groningen, The Netherlands). Cardiorespiratory variables, glycemia, angiogenic and hematological indices were measured at rest and in response to both exercise protocols. Results. The present data confirmed that the patients with type 1 diabetes demonstrated a good level of aerobic capacity and fitness. NorEx and HyEx resulted in a significant decrease in serum glucose concentration (p < 0.05 vs p < 0.01). Patients with diabetes had higher baseline hypoxia induced factor-1alpha levels compared to healthy adults (p < 0.05), which increased after exposure to hypoxia and hypoxia with exercise (p < 0.001). Hypoxia significantly decreased baseline transforming growth factor-beta (TGF-beta) (p < 0.05) and had a significant effect on tumor necrosis factor-alpha level (TNF-alpha) (F = 4.9; p < 0.05). Conclusions. Our study demonstrated that hypoxia combined with exercise reduces glycemia and may induce significant benefits in the prevention of diabetes cardiovascular complications.