Abstract

The purposes of this study were all to determine if ΔVO2/ΔWR is dependent on age, body mass, height and fitness and if ΔVO2/ΔWR could discriminate between healthy children and children with a chronic disease that limits O2 delivery or utilization. Four groups were included: muscle disease (Juvenile Dermatomyositis; JDM; n=12), lung disease (Cystic Fibrosis; CF; n=13), Congenital Heart Disease (CHD; (n=13), and healthy children (n=44). All children performed a cardiopulmonary exercise test on a cycle ergometer with respiratory gas analysis. The ΔVO2/ΔWR was determined by linear regression using data from unloaded cycling to peak exercise. No associations were found between the ΔVO2/ΔWR and age, body mass and height in healthy children. ΔVO2/ΔWR was significantly correlated with VO2peak/kg (r=0.44; p<0.01). Children with JDM had lower ΔVO2/ΔWR values than healthy children (p=0.02), and ΔVO2/ΔWR tended to be lower in CHD and higher in CF (p=0.09 and p=0.08, respectively). ΔVO2/ΔWR may be more sensitive for conditions that are characterized by local hypo perfusion (as in JDM), than for conditions that are characterized by impaired oxygen delivery (i. e. CF or CHD). Verf.-Referat