Effects of Hypoxia during Continuous and Intermittent Exercise on Glycaemic Control and Selected Markers of Vascular Function in Type 1 Diabetes

Abstract

Objectives: The aim of the study was to assess the effect of continuous and intermittent exercise in hypoxia on glycaemic control and selected markers of vascular function in patients with Type 1 diabetes (T1D).

Methods: 12 patients suffering from T1D for 12.1±6.0 years and 12 healthy adults performed: continuous exercise (ExC) and intermittent exercise (ExInt) in normoxia and hypoxia (FiO₂=15.1%). Glycaemia and proangiogenic factors concentrations were measured at rest and immediately after exercise.

Results: T1D patients' glycaemia decreased in response to ExC (p<0.01) and ExInt (p<0.05) under hypoxic conditions. ExInt in normoxia (p<0.05) and hypoxia (p<0.05) reduced HIF-1α in the T1D group. A tendency for vascular endothelial growth factor to increase after ExInt in hypoxia (6.0±3.8 vs. 17.1±13.07 pg/mL) and a proinflammatory cytokine TNF-α level to decrease (33.2±19.1 vs. 25.1±14.4 pg/mL) was found in the same group.

Conclusions: Combining exercise with hypoxia may allow more effective short-term glycaemic control in T1D. Intermittent exercise with hypoxia could stabilize the secretion of selected proangiogenic factors and reduce inflammation, potentially leading to improved vascular function.