br Body composition is modifiable by nutritional intake
Body composition is modifiable by nutritional intake and physical activity; however the impact of cancer on dietary intake
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and physical activity in paediatric and adolescent survivors before reaching adulthood is still poorly understood. Recent studies pro-vide some evidence that young survivors of childhood cancer have increased body mass index  and poor adherence to dietary and physical activity guidelines [18e21], but there is limited research examining both body composition and influencing factors in young childhood cancer survivors who have undergone treatment for a range of cancers on recent protocols. The aim of this study was to define the body composition, physical activity and dietary intake of paediatric, adolescent and young adult survivors of childhood cancer and to examine the effect of lifestyle and clinical factors on body composition in CCS.
All children, adolescents and young adults attending the After Cancer Clinic of the Royal Children's Hospital, Brisbane, who were
(1) diagnosed with cancer at an age younger than 21 years, (2) between the ages of 5e25 years at time of study, and (3) at least two years post treatment completion, were approached to be involved in the study. Patients were excluded if they had conditions know to influence dietary intake or 816-94-4 expenditure. Clinical data were retrospectively collected from medical records, including data on type of cancer, age at diagnosis, duration of treatment, time since completion of treatment and type of treatment (radiation, chemotherapy, bone marrow transplant).The study protocol was approved by the University of Queensland Medical Research Committee and the Royal Children's Hospital Brisbane Ethics Committee. Written consent was obtained from all parents of children under 18 years, participants over 12 years and verbal assent was obtained for children under 12 years.
All measurements in each subject were carried out in the Chil-dren's Nutrition Research Centre Body Composition Laboratory at the Royal Children's Hospital on the same day. Body weight was measured to the nearest 0.05 kg using calibrated digital scales (Tanita BWB-600, Wedderburn Scales, Australia) and height was measured to the nearest 0.1 cm using a wall-mounted stadiometer (Seca 222, Germany). Body mass index (BMI) was calculated as weight divided by height squared. Height, weight and BMI Z-scores were calculated using data published by the Centers for Disease Control and Prevention; all subjects over 20 years of age had Z-scores calculated relative to a 20 year old .
Measurements of body cell mass (BCM) by whole body potas-sium counting (TBK) represents the metabolically active compo-nent of fat free mass (FFM) and is independent of extracellular fluid changes genetic maps may occur as a result of disease state . TBK counting was performed as described previously using a sodium iodide shadow shield whole-body counter (Accuscan, Canberra Industries, MA, USA) . BCM was then calculated from TBK using the equation of Wang et al. : BCM (kg) ¼ (TBK (g) * 9.18)/39.1. BCM was adjusted for height (BCM index (BCMI)), with height be-ing raised to the power of 2.5 for females and 3 for males . The BCMI was expressed as a Z-score relative to laboratory reference data for subjects, all subjects and controls over 18 years of age were calculated compared to 18 year old reference data. A cut off of BCMI Z-score