Effects of Chemotherapy and Radiation Exposure on Brachial Artery Blood Flow during Dynamic Handgrip Exercise

Abstract

Chemotherapy and radiation cancer treatments have been shown to alter peripheral cardiovascular function. Therefore, the purpose of this study was to investigate if the vascular responses to dynamic handgrip exercise are blunted in individuals who have undergone chemotherapy and/or radiation treatment. To date, 1 cancer survivor (CS) and 1 healthy control (HC) have completed two dynamic handgrip exercise protocols at relative (10 and 20% maximal voluntary contraction (MVC)) and absolute (3 and 9 kg) workloads. Simultaneous measurements of forearm blood flow (FBF; Doppler Ultrasound), and mean arterial pressure (MAP) were taken during each of the workloads. Forearm vascular conductance (FVC) was calculated from MAP and FBF. Plasma concentrations of endothelial microparticles (EMPs) which are suggestive of apoptotic and activated endothelial cells (CD31+/CD42b‐ and CD62E+ EMPs, respectively) were isolated from venous blood samples. Preliminary results: FBF was decreased in CS compared to HC at: 10% MVC (111.72 vs. 228.17 ml min‐1) and 20% MVC (148.60 vs. 362.53 ml min‐1). FVC was reduced in CS when compared to HC at: 10% MVC (107.65 vs. 205.32 ml min‐1 100 mmHg‐1) and 20% MVC (135.35 vs. 287.64 ml min‐1 100 mmHg‐1). During absolute workloads FBF and FVC of the CS compared to HC was similar at 3 kg (143.91 vs. 135.26 ml min‐1 and 162.33 vs. 124.42 ml min‐1 100 mmHg‐1, respectively), but less at 9 kg (156.11 vs. 307.42 ml min‐1 and 155.24 vs. 263.54 ml min‐1 100 mmHg‐1, respectively). Due to time constraints plasma EMP concentrations are unavailable at this time. In conclusion, chemotherapy and radiation treatment in cancer survivors results in alterations to exercise blood flow regulation during dynamic exercise.