267BIOCHEMICAL INVESTIGATION OF RENAL INJURY IN PEDIATRIC ANOREXIA NERVOSABecause most studies have focused on adult populations, little is known regarding the consequences of AN in children and adolescents. Renal problems affect about 70% of Anorexia Nervosa patients at some point in their life, with a 5.2 percent chance of developing significant kidney disease, including deadly renal failure, after 21 years of Anorexia Nervosa. The goal of this study was to assess the renal function of hospitalised Anorexia Nervosa patients by measuring creatinine levels in the blood and determining the glomerular filtration rate using several formulae (GFR). In this study, the connection between GFR and intrinsic patient variables was also investigated. Cockroft–Gault, Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI), MAYO Clinic Quadratic equation (MCQ), and Schwartz formulae were used to calculate it. Unless otherwise noted, the GFR test results were adjusted to the body surface area in order to draw comparisons. The mean plus standard deviation (mean + SD) was used to report continuous variables. 45 percent of the 51 patients had a GFR of less than 90 mL/min/1.73 m2 using the Cockroft–Gault formula, compared to 28 percent using the MDRD method, 14 percent using the CKD-EPI formula, 12 percent using the MCQ formula, and 4% using the Schwartz formula. Renal issues in adolescent anorexic patients are given little attention in this therapeutic setting, leading in poor results. More study is needed to understand the link between GFR and refeeding, as well as the long-term effects of severe starvation on the kidneyManikandan@gmail.comResearch922019Renal failure, paediatric anorexia nervosa, chronic kidney disease- epidemiology collaborationSiva Manikandan M.AAssistant Professor, Department of Paediatrics & Neonatology, Government Mohan Kumaramangalam Medical College & Hospital, Salem - 636001