Incremental shuttle walking test for calf muscle oxygenation assessment in peripheral arterial disease: a cross-sectional study

Abstract

Abstract People with peripheral arterial disease (PAD) and intermittent claudication (IC) experience impaired walking due to an imbalance between muscle oxygen supply and demand during exercise. Studies with near-infrared spectroscopy (NIRS) during treadmill tests reveal notable tissue deoxygenation with slow recovery. This cross-sectional study aimed to compare behavior of calf muscle oxygenation during the incremental shuttle walking test (ISWT) with a continuous treadmill test (3.2 km/h, 10% incline) and to correlate NIRS results between tests in PAD patients. Sixty individuals with IC, 37 men (61.7%), mean age 66.25 ± 10.35 years participated in the study. Both tests were performed on the same day with a 30-minute rest, in randomized order. NIRS-derived calf muscle tissue oxygenation variables were measured at rest and during exercise. Typical PAD tissue oxygenation patterns were observed in both tests, with significant differences (p < 0.05) in oxygenation values during exercise for the variables delta of tissue oxygen saturation (ΔStO2) and reoxygenation rates. All tissue oxygenation variables analyzed, except reoxygenation rate, showed a significant and directly proportional correlation between the two tests. These results suggest that NIRS during ISWT could be a viable method for assessing tissue oxygenation in PAD.

Keywords

• Peripheral arterial disease
• Intermittent claudication
• Incremental shuttle walking test
• Near infrared spectroscopy
• Tissue oxygenation
• Calf muscle tissue oxygenation