New insights into the exercise intolerance of [beta]-thalassemia major patients

The purpose of our study was assessment of the relative contribution of the systems involved in blood gas exchange to the limited exercise capacity in patients with [beta]-thalassemia major (TM) using integrative cardiopulmonary exercise testing (CPET) with estimation of oxygen kinetics. The study consisted of 15 consecutive TM patients and 15 matched controls who performed spirometric evaluation, measurement of maximum inspiratory pressure (Pimax) and an incremental symptom-limited CPET on a cycle ergometer. Exercise capacity was markedly reduced in TM patients as assessed by peak oxygen uptake (pVO2, mL/kg/min: 22.1±6.6 vs 33.8±8.3; P