The Impact of Exercise on Growth Hormone Deficient Adolescent and Young Adult Survivors of Childhood Cancer: a pilot study

INTERVENTION: The exercise program consists of thrice weekly supervised exercise sessions aimed at increasing exercise capacity. Each session will last for about 1 hour and consist of a small group with each participant having a personally tailored program. This will continue for 6 months. Intensity will be monitored during exercise sessions using heart rate monitors and rate of perceived exertion (Borg scale). During the intervention phase, exercise intensity will be maintained in the moderate intensity and not enter into vigorous intensity (>60% VO2R). The key components of the exercise intervention include resistance training to increase lean muscle mass, and aerobic training to increase aerobic fitness. Each exercise program will be fully supervised and designed in accordance with the American College of Sports Medicine (ACSM) guidelines(Franklin BA, Whaley MH, and Howley ET. ACSM's Guidelines for exercise testing and prescription (6 ed.). Philadelphia: Lippincott Williams and Wilkins, 2000). The program will consist of a 10 min warm up period, with light stretching, followed by 30‐45 min of a circuit‐based program which will use a combination of both endurance (65‐85% of HRmax, monitored continuously using a Polar heart rate monitor) and resistance (55‐70% maximal voluntary contraction) exercises, and a 10 min cool down. Intensity and duration will be increased, first by extending the number of sets, then by the weight lifted. We have previous experienced high levels of compliance and participation using this form of training in a similar population group, who are young, and generally not highly motivated to participate in physical activities. CONDITION: growth hormone deficiency survivor of childhood cancer PRIMARY OUTCOME: impact of exercise on metabolic parameters including: Oral glucose tolerance test results (analysed using HOMA2 scores), serum HbA1c, fasting lipid profile and auxological data. SECONDARY OUTCOME: Impact of exercise on cardiovascular parameters: ; Every candidate will have an echocardiogram within the 12 months prior to commencing the program. This will be repeated at the end of the 6 month exercise program. Furthermore, endothelial function will be assessed using flow mediated dilation which has been demonstrated to be an independant predictor of cardiac events. ; Flow mediated dilation is assessed as follows: ; Following a one minute recording of resting brachial artery diameter by ultrasound, a forearm cuff placed distal to the olecranon process, will be inflated to 220mmHg for five minutes. Diameter and blood flow recordings will resume 30 seconds before cuff deflation and continue for three minutes. ; Impact of exercise on psychosocial wellbeing: ; A series of psychological assessments will be administered at baseline and again after the exercise intervention. The psychometric battery will include face‐to‐face assessments and parent‐report questionnaires. ; Tests used: ; Wechsler Abbreviated Scale of Intelligence (WASI) ; Test of Everyday Attention (TEA) ; Wechsler Memory Scale – 3rd Edition (WMS‐III) ; Grooved Pegboard ; ASEBA Youth Report (YSR) ; ASEBA Adult Self‐Report (ASR) ; Behavior Assessment System for Children – Self‐report (BASC‐2) ; Adaptive Behavior Assessment System – 2nd Edition (ABAS‐II) ; Behavior Rating Inventory of Executive Function – Adult (BRIEF‐A) ; PedsQL 4.0 (Generic Version) ; Parent‐reported questionnaires: ; Behavior Assessment System for Children – 2nd Edition, parent‐report (BASC‐2) ; Behavior Rating Inventory of Executive Function (BRIEF) ; ; INCLUSION CRITERIA: 1. Survivor of childhood brain cancer or cranial irradiation at a dose sufficient to potentially result in GH deficiency 2. Current age 15‐23