XDH and Huntington disease: A large-scale prospective interventional study that includes measurements of ROS, oxidative stress, and ATP levels in skeletal muscle and blood, as well as physical activity, and also includes analysis of dosage, duration, and XOR inhibitor indication in HD patients, including those with markedly reduced activities of daily living, is needed to clarify the role of XOR inhibitor treatment for prevention and treatment of sarcopenia in HD patients.