13: Renal function and complications in children with Intestinal Failure on Long-Term Parenteral Nutrition

Introduction: Long-term parenteral nutrition (PN) has been associated with renal complications, including hypercalciuria, nephrocalcinosis/nephrolithiasis, proteinuria and reduced glomerular filtration rate (GFR). Pediatric data are scarce and mostly short-term or restricted to transversal studies. Our study aimed to evaluate renal complications in children with intestinal failure (IF) receiving long-term PN. Methods: We performed an observational longitudinal study of patients with IF followed up in a pediatric intestinal rehabilitation center. Outcome variables were estimated glomerular filtration (eGFR) rate, hypercalciuria, nephrocalcinosis/nephrolithiasis, proteinuria, phosphaturia and oxaluria during the follow-up period. The exposure variables were age, duration of parenteral nutrition and type of short bowel syndrome (SBS). The study was approved by the hospital’s ethics committee. Methods: Twenty-four children (54% males), aged 74 months (16; 205) with a median time receiving parenteral nutrition of 47.5 months (IQ 26.5). Data related to renal function were evaluated in two moments, with a median interval of 8 months (IQ 4.5 months). Hypercalciuria was observed in 60.8% and 58.3%, increased phosphaturia in 25% and 18.7%, increased oxaluria in 36.8% and 25% and increased microalbuminuria/proteinuria was observed in 19% and 13.6% of patients, respectively, at moments 1 and 2. Despite de high incidence of hypercalciuria, nephrolithiasis was observed in one patient. In addition to the patient with nephrolithiasis, small and hyperechogenic kidneys were observed in another patient in the image evaluation. The median eGFR rate was 164.5 ml/min/1.73m2 (IQ 52.7) and 195 ml/min/1.73m2 (IQ 38.7) at moments 1 and 2, respectively. There was only one patient with reduced eGFR (77.7 and 78 ml/min/1.73m2) at both times. A significant association was observed between SBS (type 3) and eGFR, with β-coefficient = - 41.07 (95% confidence interval [CI], -66.5; -15.6, p=0,002). Conclusion: The high frequency of hypercalciuria, microalbuminuria and proteinuria, in addition to the state of glomerular hyperfiltration represent risk factors for long-term renal dysfunction. Despite the high incidence of hypercalciuria, nephrocalcinosis/nephrolithiasis was observed in olnly one patient. Long-term monitoring of various aspects of renal function is essential to characterize the effects of prolonged PN on kidney functions in pediatric patients.