MICROVASCULAR OXYGENATION RESPONSE DURING PADDLING GRADED EXERCISE TEST IN BREAST CANCER SURVIVOR DRAGON BOAT RACERS

Abstract

Cancer treatment is associated with numerous peripheral pathologies including altered blood flow and vascular dysfunction. A pilot study was conducted to measure the peripheral microvascular oxygenation response during maximal exercise in a group of cancer survivors. PURPOSE: To investigate the differences that paddling side (paddling side, PS; non-paddling side, NPS) and treatment side (treatment side, TREAT; healthy side, HEAL) has on the near-infrared spectroscopy (NIRS) responses during a unilateral paddling graded exercise test in breast cancer survivor dragon boat racers. METHODS: Thirteen breast cancer survivors/racers (56 ± 9 years, 1.65 ± 0.06 m, 76.5 ± 11.0 kg) performed a unilateral, discontinuous graded exercise test (2-minute exercise, 1-minute rest) on a stationary rowing ergometer to volitional fatigue. Tissue oxygenation saturation (StO2) and total hemoglobin concentration ([THC]) were measured via NIRS from the posterior deltoid muscles during the graded exercise test. StO2 and [THC] responses were averaged during the last 30 seconds of each exercise stage and normalized to baseline exercising data. Paired t-tests were used to examine if treatment side had an effect on StO2 or [THC] and if paddling side had an effect on [THC] responses at maximal intensity. Due to non-normally distributed data, a Wilcoxon Signed Rank Test was used to determine if paddling side had an effect on StO2 at maximal intensity. Significance was established a priori at p < 0.05. RESULTS: Paddling side did not significantly affect the StO2 (PS = -5.2 ± 15.7%, NPS = -13.5 ± 21.7%, p = 0.094) or [THC] (PS = 0.14 ± 0.19, NPS = 0.15 ± 0.21, p = 0.425) responses. Treatment side had a significant, moderate (ES = 1.12) effect on the StO2 response (TREAT = -0.006 ± 16.1%, HEAL = -18.7 ± 17.3%, p = 0.008). Treatment side did not significantly affect the [THC] response (TREAT = 0.13 ± 0.20, HEAL = 0.16 ± 0.19, p = 0.313). CONCLUSION: Based upon the pilot results, it would suggest that the exercising muscles on the breast cancer treatment side may have a residual impaired ability to use oxygen for energy production during maximal intensity exercise.