Resumen de Preliminary Findings of a 4-Month Intrahospital Exercise Training Intervention on IGFs and IGFBPs in Children with Leukemia

Jonatan Ruíz Ruíz, Steven J. Fleck, Jakob L. Vingren, Manuel Ramírez Orellana, L. Madero López, Maren S. Fragala, William J. Kraemer, Alejandro Lucía Mulas

• The aim of this study was to determine the effect of a 16-week intrahospital supervised, conditioning program including both resistance and aerobic type training on insulin-like growth factors 1 and 2 (IGF-1, IGF-2), several IGF-binding proteins (IGFBPs), and growth hormone (GH) in children receiving treatment against acute lymphoblastic leukemia (ALL). We also analyzed the effects of a 20-week detraining period on these hormones. Seven children (3 girls and 4 boys) aged 4-7 years in the maintenance phase of treatment against ALL performed 3 training sessions per week for 16 weeks of resistance (1 set of 8-15 repetitions of 11 exercises) and aerobic training (30 minutes at >=50% heart rate max) followed by 20 weeks of detraining where no structured exercise program was performed. Levels of IFG-1 and IFG-2 did not significantly change after the intervention period or after the detraining phase. Likewise, levels of GH, IGFBP-2, and IGFBP-3 remained stable pre and posttraining and after the detraining period. IGFBP-1 levels significantly decreased after training (-43.8%, p = 0.014), whereas there were no significant differences between pretraining vs. detraining (-17.8%, p = 0.108) nor between posttraining vs. detraining (17.7%, p = 0.251). Exercise training did not have major effects on the IGFs, IGFBPs, and GH in children with ALL. Although the importance of these findings to long-term cancer prognosis and/or recurrence remains to be determined, the present data (particularly those on IGF-1 and IGFBP-3) support the idea that exercise training can be safely undergone during treatment against ALL with no major adverse effect.