Thesis (MNutr)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Introduction and purpose The aim of the study was to determine the renal handling of a once-off bolus dietary protein load in patients treated for nephroblastoma. Patients who have been managed for nephroblastoma always have suboptimal amounts of kidney tissue as a result of their medical management which includes nephrectomies, chemotherapy and or radiotherapy. Little data are available indicating the extent of renal impairment expected in such patients as a result of their disease and management. The study was to determine whether the use of regular screening tests such as serum urea, creatinine and urine microalbumin, in conjunction with a dietary protein load could help detect early progressive deterioration of kidney function in nephroblastoma patients. Methodology The study was a quantitative non-randomised intervention study in which patients served as their own control before and after a protein load. Thirty-four participants were included in the study. Each participant was provided with a supplemental protein drink providing 2 g/kg body weight of protein. Serum creatinine, urea and urine microalbumin were assessed at baseline and four hours after the intervention. These pre- and post intervention biochemical values were then analysed together with descriptive data relating to the participants, such as age, stage of nephroblastoma, aspects of medical management and the period of time since they had been treated for nephroblastoma, and statistical relationships were assessed. Data were collected from May 2010 to November 2010. Results Descriptive statistics indicated that the mean [± Standard deviation (SD)] age of the population was 92 (± 55) months, the mean age at diagnosis was 41 (± 27) months and the mean age from the diagnosis to the time of the study was 51 (± 53) months. There was a statistically significant increase (p = 0.00) in serum urea post intervention; however, no significant difference was noted between pre- and post intervention serum creatinine and urine microalbumin values. The stages of nephroblastoma failed to show a statistical correlation with the response to the dietary protein bolus load in terms of the difference in pre- and post intervention biochemical data. No statistical correlation was found between post-pubescence and response to the protein load. Similiarly, no statistical correlation could be demonstrated for a longer period between the diagnosis and the time of this study, on the one hand, and the prevalence of high values in the biochemical data, on the other. Conclusion The study was unable to demonstrate statistically that participants managed for nephroblastoma had poor renal handling of a once-off dietary protein load in terms of the objectives specified. The study had limitations including a small population with even smaller subgroups of participants, therefore results of the study need to be interpreted in context to the size of the population. / AFRIKAANSE OPSOMMING: Doel Die doel van die studie was om die renale hantering van ’n eenmalige bolus dieetproteïenlading by pasiënte wat vir nefroblastoom behandel word, te bepaal. Pasiënte wat vir nefroblastoom behandel word, het altyd ‘n subopitmale hoeveelheid nierweefsel as gevolg van hulle mediese behandeling wat nefrektomies, chemoterapie en / of radioterapie insluit. Min data is beskikbaar omtrent die omvang van die nierbelemmering wat in sulke pasiënte verwag word as gevolg van hulle siekte en behandeling. Die studie is uitgevoer om te bepaal of die gebruik van gereelde siftingstoetse soos serum-ureum, kreatinien en mikroalbuminurie, in samewerking met ‘n dieetproteïenlading, kan help om vroeë progressiewe agteruitgang van nierfunksie in nefroblastoom pasiënte, op te spoor. Metodologie Die studie was ‘n kwantitatiewe nie-ewekansige intervensie studie waar pasiënte as hul eie kontrole gedien het voor en na ‘n proteïenlading. Altesaam 34 deelnemers is by die studie betrek. Elke deelnemer het ’n proteïenaanvullingsdrankie ontvang wat 2 gram proteïen per kilogram liggaamsgewig voorsien het. Serumkreatinien, serum-ureum en mikro-albuminurie is op die basislyn sowel as vier uur na die intervensie gemeet. Hierdie biochemiese waardes voor en na die intervensie is daarna saam met beskrywende data van die deelnemers – soos ouderdom, stadium van nefroblastoom, aspekte van mediese behandeling en tydsverloop sedert behandeling vir nefroblastoom – ontleed. Statistiese verwantskappe is vervolgens beoordeel. Data is vanaf Mei 2010 tot November 2010 ingesamel. Resultate Beskrywende statistieke het op ’n gemiddelde [± Standaard afwyking (SA)] populasie-ouderdom van 92 (± 55) maande, ’n gemiddelde diagnose-ouderdom van 41(± 27) maande en ’n gemiddelde ouderdom van 51(± 53) maande vanaf diagnose tot en met die studie gedui. Ná die intervensie is ’n statisties beduidende toename (p = 0.00) in serum-ureum opgemerk, hoewel daar geen beduidende verskil in serumkreatinien en mikro-albuminurie waardes, voor en na behandeling, was nie. Biochemiese data voor en na die intervensie het geen statistiese verwantskap tussen die stadium van nefroblastoom en die reaksie op die dieetproteïenlading getoon nie. Boonop is geen statistiese verwantskap opgemerk tussen post-pubesensie en die reaksie op die proteïenlading, of tussen ’n langer tydsverloop tussen die diagnose en die studie en die voorkoms van hoë waardes in die biochemiese data nie. Gevolgtrekking Wat die studie-doelwitte betref, kon die navorsing nie statisties bewys dat deelnemers wat vir nefroblastoom behandel word, swak renale hantering van ’n eenmalige dieetproteïenlading toon nie. Die beperkinge van die studie sluit ‘n klein populasie met selfs kleiner subgroepe in; die resultate van die studie moet derhalwe in die konteks van die grootte van die populasie, geÏnterpreteer word.