Pediatr Nephrol (2004) 19:1253–1261 DOI 10.1007/s00467-004-1581-2 ORIGINAL ARTICLE Lisa J. Norman · Ian A. Macdonald · Alan R. Watson Optimising nutrition in chronic renal insufficiency— progression of disease Received: 24 October 2003 / Revised: 26 May 2004 / Accepted: 27 May 2004 / Published online: 3 September 2004  IPNA 2004 Abstract There is a lack of evidence to support the belief that dietary measures are beneficial in slowing the pro- gression of chronic renal insufficiency (CRI). We pro- spectively monitored nutrient intakes and progression of CRI over a 2-year period in children aged 2–16 years with differing levels of severity of CRI, as part of their ongoing joint medical/dietetic care. Children were grouped fol- lowing [ 51 Cr]-labelled EDTA glomerular filtration rate (GFR, ml/min per 1.73 m 2 ) estimations, into ‘normal’ kidney function [GFR >75, mean 106 (SD 19.5), n=58], providing baseline data only, mild (GFR 51–75, n=25), moderate (GFR 25–50, n =21), and severe (GFR <25, n=19) CRI. Children with CRI were followed for 2 years, with 51 completing the study (19 mild, 19 moderate, 13 severe CRI) and were excluded if they subsequently re- quired dialysis. Regular medical and dietary advice was provided and yearly 3-day semi-quantitative dietary di- aries and baseline and 6-monthly measurements of blood pressure and urinary protein/creatinine ratio were ob- tained. Mean reductions in estimated GFR over 2 years were –9.4, 5.8, and –6.0 ml/min per 1.73 m 2 for mild, moderate, and severe CRI, respectively. Mean systolic blood pressure standard deviation score (SDS) fell sig- nificantly in all groups by 0.7 SDS, whereas there was little change in proteinuria. From reported dietary intakes, median sodium intakes increased (+10 mmol/day) and protein intakes decreased (0.4 g/kg per day). Median phosphate intakes did not change significantly, whereas calcium intakes fell in all groups, with an overall median of –20% reference nutrient intake (RNI) (F=33.3, P<0.001). Of children with moderate CRI, 65% finished with calcium intakes below 80% RNI, and parathyroid hormone (PTH) concentrations significantly increased in this group (F=6.0, P=0.021). Higher phosphate and so- dium intakes were associated with greater deterioration in estimated GFR in children with mild CRI (r 2 =0.30, P=0.02; r 2 =0.31, P=0.02, respectively). There was no such correlation for protein intake or PTH. This study emphasises the need for a joint medical and dietetic ap- proach and indicates a number of interventions other than protein restriction, which could be commenced early in children with CRI in an attempt to delay progression. Keywords Chronic renal insufficiency · Disease progression · Dietary restriction · Phosphorus · Sodium · Protein · Calcium Introduction Risk factors for progression of kidney disease include hypertension, proteinuria, high-protein diets, phosphate retention, and metabolic acidosis [1]. Increasing emphasis is being placed on the importance of early intervention in the course of chronic renal insufficiency (CRI) in adults, due to renal failure not only being a clinical concern, but also a growing economical and organisational problem associated with provision of renal replacement therapy [2]. While it is acknowledged that dietary manipulations for optimal growth are effective in infants with CRI, there is more scepticism in striving for optimal nutrition in the older child with CRI [3]. This is related, in part, to the minimal reduction in progression of CRI observed fol- lowing reduced protein intakes [4]. Strict low-protein diets are limiting to growth and can impact on energy intake [4, 5], thereby potentially contributing to malnu- trition. Numerous dietary restrictions have been associ- ated with reduced patient satisfaction with treatment [6]. L. J. Norman · A. R. Watson Children and Young People’s Kidney Unit, Nottingham City Hospital, Nottingham, UK I. A. Macdonald School of Biomedical Sciences, Medical School, University of Nottingham, UK L. J. Norman ( ) ) Department of Nutrition and Dietetics, Nottingham City PCT, 261 Beechdale Road, Aspley, Nottingham, NG8 3EY, UK e-mail: lisa.waddell@nottinghamcity-pct.nhs.uk Tel.: +44-115-9428745 Fax: +44-115-9428748