Relationship between cardiopulmonary response to exercise and adiposity in survivors of childhood malignancy.

Many long term sequelae result from previous treatment for malignancy in childhood. However, little information exists on cardiopulmonary response and energy expenditure during exercise and their possible associations with excess body fat. Measurements of body composition and exercise capacity both at low intensity and maximal aerobic capacity were made on 56 long term survivors of childhood malignancy (35 survivors of acute lymphoblastic leukaemia (ALL) and 21 survivors of other malignancies) and 32 siblings acting as controls. Female survivors of ALL had significantly greater mean (SD) body fat than survivors of other malignancies and siblings (32.5 (6.4)% v 24.3 (4.4)% and 26.3 (8.5)% respectively, p < 0.005). Energy expenditure at low intensity exercise was reduced in survivors of ALL, and negatively correlated with body fat after controlling for weight (partial r range -0.21 to -0.47, p < 0.05). Stroke volume, measured indirectly, was reduced and heart rate raised in ALL survivors at sub-maximal exercise levels. Peak oxygen consumption was significantly reduced in girls and boys treated for ALL compared with siblings (30.5 v 41.3 ml/kg/min for girls, p < 0.05 and 39.9 v 47.6 ml/kg/min for boys, p < 0.05 respectively). Reduced exercise capacity may account in part for the excess adiposity observed in long term survivors of ALL.