Purpose: To evaluate the acute effect of aerobic exercise (AE) and resistance exercise (RE) on the release of endothelial progenitor cell (EPCs, CD34+/KDR+/CD45 dim) and vascular function in type 1 diabetes (T1DM).
Methods: Fourteen men with T1DM and 5 nondiabetic controls were randomly assigned to 40-min AE (60% VO 2peak) and RE sessions (60% 1-RM). The study had a crossover design, and interventions were 1 wk apart. Venous occlusion plethysmography (blood flow, reactive hyperemia, and vascular resistance) and blood collection (EPC levels, flow cytometry) were done immediately before and after exercise sessions.
Results: Patients were 30.3 ± 1.6 yr-old, HbA1c 7.7% ± 0.2%; controls were 26.8 ± 2.3 yr-old. Groups did not differ in EPC levels at baseline or in relation to exercise. Over time, exercise did not induce changes in patients with T1DM, whereas, in controls, EPCs were decreased after AE (-10.7%, P = 0.017) and increased after RE (+12.2%, P = 0.004). Compared with baseline, blood flow increased and vascular resistance decreased after RE in both groups. Reactive hyperemia was increased 10 min after AE and RE sessions in patients with T1DM (36.5% and 42.0%, respectively) and in controls (35.4% and 74.3%), but no group differences were observed between groups in response to exercise.
Conclusions: Despite the increased vascular reactivity in both groups after both exercise sessions, EPCs were only influenced by exercise in controls. The unchanged number of EPCs in T1DM after exercise sessions might indicate a blunted endothelium regenerating capacity, revealing an early deterioration of the functional arterial characteristics not disclosed by only evaluating vascular functional variables.