Combined Amino-Acid and Glucose Peritoneal Dialysis Solution for ...

Advances in Peritoneal Dialysis, Vol. 20, 2004Johan Vande Walle, Ann Raes, Joke Dehoorne, ReinerMauel, Annick Dejaeghere, Dirk MatthysCombined Amino-Acid andGlucose Peritoneal DialysisSolution for Children withAcute Renal FailurePeritoneal dialysis (PD) solutions with amino acids(AAs) were developed as an alternative to glucosebasedPD solutions for chronic renal failure. AlthoughAA solution has many theoretical advantages,the results reported in the literature are still notconvincing.Treatment of ARF is a complex problem. To tackleit, we investigated a PD solution based on a mixtureof Nutrineal (Baxter Healthcare SA, Castlebar, Ireland)and Dianeal (Baxter Healthcare SA), mixed onthe heating plate of the PAC Xtra cycler (BaxterHealthcare SA). The resulting solution was expectedto lower the glucose load without affecting dialysisadequacy. We retrospectively analyzed data in childrentreated with the mixture, and evaluated safety,dialysis adequacy, acidosis, and nutritional state(albumin).Glucose reabsorption and protein losses were significantlylower when mixed AA–glucose solution wasused. Despite significant AA absorption in the patients,we observed no significant difference in plasma albuminlevels. Reabsorption from the dialysate of AAsvaried between 21% and 69%, resulting in 27% ± 12%of daily AA intake. Reabsorption of glucose from thedialysate was 32% – 72%.In children in intensive care, who are often alreadyvery sensitive, an AA-containing mixture mayhelp to control glycemia, subsequently reducing theneed for insulin. Our data demonstrate that the calculatedpercentage reabsorption of glucose and AAsis high and that AA levels in plasma remain stable.Although our data do not demonstrate a potential influenceon final outcome, they demonstrate the feasibilityand safety of using combined AA–glucosesolution, with a calculated resorption that lends nutritionalsupport.From: Pediatric Nephrology and Intensive Care (Cardiology),University Hospital, Gent, Belgium.Key wordsAcute renal failure, children, bicarbonate dialysis solution,low-sodium dialysis solutionIntroductionPeritoneal dialysis (PD) solutions with amino acids(AAs) were developed as an alternative for glucosebasedPD solutions for chronic renal failure. AlthoughAA solution has many theoretical advantages, the resultsreported in the literature are still not convincing.Also, data in children are limited, and, experts are veryreluctant to endorse AA solution in dialysis guidelines(1,2).The major indication for AA solution is nutritionalsupport in malnourished adult patients (3). In children,however, support for malnutrition is a minorconcern, because a gastrostomy is the treatment ofchoice (4). The major indication for AA solution inchronic dialysis in children is therefore probably preservationof the peritoneal membrane by reduction ofthe glucose load, especially when glucose solutionsare used overnight in automated PD (APD). In acuterenal failure (ARF), the situation may be different.Treatment of ARF is a complex problem. Cardiorespiratoryinstability often forces a choice for APD,with frequent cycles and low fill volumes of hypertonicglucose solution. The hypertonic glucose ofteninduces hyperglycemia in the intensive care patients,who often already have hyperglycemia (5,6). Not onlyis insulin treatment often required, but the high plasmaglucose and osmolality also limit ultrafiltrationefficiency.To tackle this problem, we investigated a dialysissolution based on a mixture of Nutrineal (BaxterHealthcare SA, Castlebar, Ireland) and Dianeal (BaxterHealthcare SA), mixed on the heating plate of the PACXtra cycler (Baxter Healthcare SA). The resultingsolution was expected to lower the glucose load withoutaffecting dialysis adequacy.

Vande Walle et al.Patients and methodsWe retrospectively analyzed data in children treatedwith an AA-based PD solution (Nutrineal) mixed withDianeal in a cycler. We evaluated safety, dialysis adequacy,acidosis, and nutritional state (albumin). Weperformed an AA analysis to evaluate whether the socalledNO-related AAs were increased in plasma,which could possibly lead to risk of shock andvasodilatation.The study group consisted of 33 patients who weretreated for ARF for at least 72 hours at our hospitalduring the period 1993 – 2000. The cycler was programmedfor cycles of 10 minutes inflow, 100 minutesdwell time, and 10 minutes outflow. Glucosesolution was used for the first 48 hours. From 48 hoursto 72 hours, the solution combined 1 bag of Nutrineal1.1% and 1 bag of Dianeal 3.86%.We measured the dialysate and plasma AA concentrations(Figure 1), the plasma AA concentrationsbefore and after Nutrineal (Figure 2), and dialysateparameters. We calculated peritoneal reabsorption(glucose and AAs) and determined blood urea nitrogen(BUN), creatinine, serum albumin, body parameters,and dialysis adequacy.227ResultsWe observed no significant differences in plasmacreatinine, BUN, acidosis, or ultrafiltration rate beforeand after use of Nutrineal. Glucose reabsorptionand protein losses were significantly lower whenmixed AA–glucose solution was used. Despite significantAA absorption, we observed no significantdifference in plasma albumin levels. Reabsorptionfrom the dialysate of AAs varied between 21% and69%, resulting in 27% ± 12% of daily AA intake.Reabsorption of glucose from the dialysate was 32% –72%.Figure 1 shows that the relative concentrationsof several AAs were different in dialysate and plasma.The large standard deviations for the measured dialysateconcentrations may be surprising, but theydo not suggest a manufacturing problem. Rather, theyare related to the different size and format of theNutrineal and Dianeal bags, which produce a slightdisequilibrium as the 2 bags pump up to the heatingplate.Figure 2 shows that, after 48 – 72 hours, plasmaAA levels were not significantly changed (especiallyarginine concentration).FIGURE 1Dialysate and plasma levels of amino acids (AA) for the study patients.

228Combination PD Solution in Children with ARFFIGURE 2 Plasma levels of free amino acids (AA) for the study patients before and after treatment with combined amino-acid andglucose dialysis solution.DiscussionThe introduction of APD into clinical practice in anintensive care unit raises several metabolic problemsand affects the nutrition status and the acid, electrolyte,and fluid balance of the patients (7). The optionof continuous renal replacement therapy therefore offersthe ability to ultrafilter and to dialyze to the desiredlevel and to deliver high nutritional support(1,8–10). But what is often forgotten is that more ultrafiltrationrequires more substitution and that “more”has not always been proven to be “better.” There maybe a place to optimize softer types of renal replacementtherapy such as PD. The present study demonstratesthat modifying conventional PD may result insignificant nutritional support, better metabolic homeostasis,and fewer side effects (hyperglycemia, needfor insulin).The possibility of using PD itself as a source ofnutrients in the treatment of malnutrition is an intriguingconcept (11). Unfortunately, it is not possible toproduce dialysis solution that contains both glucoseand AAs because of technical problems of preservation(such as crystallization and caramelization) unlessa multiple-compartment system such as that currentlyused for bicarbonate-buffered solution is developed.Hence, the simultaneous infusion of glucoseand AAs is not possible in continuous ambulatory PDin adults (11,12). Automated PD (APD), which isbased on the use of a cycler, permits different solutionsto be simultaneously pumped from reservoir bagsinto an empty bag on the heating plate, thereby producinga reasonably homogeneous mixture. In theory,1 glucose bag can be mixed with 1 AA bag to obtain50% of each, or 2 glucose bags could be mixed with1 AA bag for patients who need a reduced AA load.Various options are possible.In APD, a combined AA and glucose solutionrather than the traditional single daily bag of Nutrinealis potentially superior for reaching anabolic goals, forthese reasons:• An optimal anabolic effect requires AAs and glucoseto be delivered together.• Large glucose-induced changes in insulin areavoided.• Loss of AAs in glucose dwells (3 of 4) is avoided.

Vande Walle et al.229Soon after the introduction of Nutrineal, thosetheoretical considerations were already documentedin clinical practice. Indeed, in almost all of the studieson the use of intraperitoneal AAs, a significantincrease in serum levels of urea were reported, suggestingunsatisfactory utilization of the infused AAs(11,12). Moreover, it is well known that, without anenergy source, nitrogen will not be effectively incorporatedinto proteins.In parenteral nutrition, the combined infusion ofnon protein calories and AAs has been a key factorin ensuring the optimal utilization of the AAs. Totalparenteral nutrition (TPN) solutions with a ratio of150:1 (non protein calories to nitrogen) are consideredappropriate for most patients to incorporate deliveredAAs into new proteins. A mixture of Nutrinealand Dianeal simultaneously achieves three conditionsfavorable for protein synthesis: hyperinsulinemia,hyperaminoacidemia, and an adequate ratio of nonprotein calories to nitrogen (absorbed glucose toAAs).These considerations are of even more importancein intensive care units, where most patients are catabolic,lack enteral nutrition, and require ultrafiltrationfor every parenteral milliliter administered. The useof combined glucose–AA solutions in a peritoneumwith hyperemic dilated vessels will result in significantperitoneal resorption. That resorption may meeta significant percentage of the patient’s nutritionalneeds (AAs and glucose), limiting the need for intravenousadministration of TPN. Limiting intravenousfluid administration helps to eliminate the need forultrafiltration by dialysis.In children in intensive care, who are often alreadyvery sensitive, an AA-containing mixture may helpto control glycemia, subsequently reducing the needfor insulin. Our data demonstrate that the calculatedpercentage reabsorption of glucose and AAs is highand that plasma AA levels remain stable. The reabsorptiondata are comparable with data reported byCanepa et al. and Qamar et al. (13–17).Adequate protein and energy intake are essentialto the maintenance of nitrogen balance and the preventionof malnutrition in intensive care. Treatmentwith oral calorie and protein supplements is oftenimpossible, but intravenous administration of TPN isoften limited by the excessive fluid load imposed on apatient in anuria by the need to reach a given nutritionaltarget. The use of AA-based dialysis fluid combinedwith glucose may provide opportunities to compensatefor dialytic losses of protein and AAs and tosupplement inadequate dietary protein intake, withsubsequent improvement in nutritional status, becauseof the resulting anabolic benefit and limitation of unnecessaryAA metabolism.ConclusionsAlthough our data do not demonstrate a potential influenceon final outcome, they demonstrate the feasibilityand safety of using combined AA–glucosesolution, with a calculated resorption that lends nutritionalsupport.References1 Strazdins V, Watson AR, Harvey AR. Renal replacementtherapy for acute renal failure in children: Europeanguidelines. Pediatr Nephrol 2004; 19:199–207.2 Schroder CH and the European Paediatric PeritonealDialysis Working Group. The choice of dialysis solutionsin pediatric chronic peritoneal dialysis: guidelinesby an ad hoc European committee. Perit Dial Int2001; 21:568–74.3 Kopple JD, Bernard D, Messana J, et al. Treatment ofmalnourished CAPD patients with an amino acidbased dialysate. Kidney Int 1995; 47:1148–57.4 Coleman JE, Watson AR, Rance CH, Moore E. Gastrostomybuttons for nutritional support on chronicdialysis. Nephrol Dial Transplant 1998; 13:2041–6.5 Flynn JT, Kershaw DB, Smoyer WE, Brophy PD,McBryde KD, Bunchman TE. Peritoneal dialysis formanagement of pediatric acute renal failure. PeritDial Int 2001; 21:390–4.6 Vande Walle J, Raes A, Castillo D, Lutz–Dettinger N,Dejaegher A. New perspectives for PD in acute renalfailure related to new catheter techniques and introductionof APD. Adv Perit Dial 1997; 13:190–4.7 Vande Walle J, Raes A, Castillo D, Lutz–Dettinger N,Dejaegher A. Advantages of HCO 3solution with lowsodium concentration over standard lactate solutionsfor acute peritoneal dialysis. Adv Perit Dial 1997; 13:179–82.8 Goldstein SL. Overview of pediatric renal replacementtherapy in acute renal failure. Artif Organs2003; 27:781–5.9 Maxvold NJ, Smoyer WE, Gardner JJ, BunchmanTE. Management of acute renal failure in the pediatricpatient: hemofiltration versus hemodialysis. Am JKidney Dis 1997; 30(Suppl 4):S84–8.10 Symons JM, Brophy PD, Gregory MJ, et al. Continuousrenal replacement therapy in children up to10 kg. Am J Kidney Dis 2003; 41:984–9.

23011 Park MS, Heimbürger O, Bergström J, Waniewski J,Werynski A, Lindholm B. Peritoneal transport duringdialysis with amino acid–based solutions. Perit DialInt 1993; 13:280–8.12 Dombros NV, Prutis K, Tong M, et al. Six-monthovernight intraperitoneal amino-acid infusion in continuousambulatory peritoneal dialysis (CAPD) patients—noeffect on nutritional status. Perit Dial Int1990; 10:79–84.13 Canepa A, Carrea A, Menoni S, et al. Acute effectsof simultaneous intraperitoneal infusion of glucoseand amino acids. Kidney Int 2001; 59:1967–73.14 Canepa A, Perfumo F, Carrea A, et al. Long-term effectof amino-acid dialysis solution in children oncontinuous ambulatory peritoneal dialysis. PediatrNephrol 1991; 5:215–19.15 Canepa A, Perfumo F, Carrea A, et al. ContinuousCombination PD Solution in Children with ARFambulatory peritoneal dialysis (CAPD) of childrenwith amino acid solutions: technical and metabolicaspects. Perit Dial Int 1990; 10:215–20.16 Qamar IU, Secker D, Levin L, Balfe JA, Zlotkin S,Balfe JW. Effects of amino acid dialysis compared todextrose dialysis in children on continuous cyclingperitoneal dialysis. Perit Dial Int 1999; 19:237–47.17 Canepa A, Filho JC, Gutierrez A, et al. Free aminoacids in plasma, red blood cells, polymorphonuclearleukocytes, and muscle in normal and uraemic children.Nephrol Dial Transplant 2002; 17:413–21.Corresponding author:Johan Vande Walle, MD, Renal Unit, University Hospital,185 De Pintelaan, B-9000 Gent, Belgium.E-mail:Johan.VandeWalle@Ugent.be

Advances in Peritoneal Dialysis, Vol. 20, 2004Marta A. Azocar, 1 Francisco J. Cano, 1 Verónica Marin, 2Maria A. Delucchi, 1 Eugenio E. Rodriguez 1Body Composition inChildren on PeritonealDialysisDual-energy X-ray absorptiometry (DEXA) can beused to evaluate total-body bone mineral content(BMC), bone mineral density (BMD), fat-free mass(FFM), and fat body mass (FBM), which are all frequentlyaffected in patients (PD) on peritoneal dialysis.We used DEXA to evaluate body composition inchildren on PD and to establish whether relationshipsexisted with nutrition status, dialytic parameters, andbiochemical data.We evaluated 20 PD patients (12 boys, 8 girls).The mean age of the patients was 5.84 years (range:0.16 – 14.66 years). We carried out DEXA, anthropometry(weight/age, height/age, and body massindex), and measurements of dietary intake (protein,energy, calcium, and phosphorus), nitrogen balance(NB), dialysis dose (Kt/V), peritoneal equilibrium test(PET), and plasma calcium, phosphorus, and bicarbonateat months 1 and 6 of the study. Energy intakewas prescribed according to the United States RecommendedDietary Allowances, and Kt/V and dailyprotein intake (DPI) according to the Dialysis OutcomesQuality Initiative (DOQI) guidelines.In the patients, BMD increased to 0.769 ± 0.174 g/cm 2 from 0.747 ± 0.166 g/cm 2 (p < 0.05), and BMCincreased to 680.3 ± 666.1 g from 632.6 ± 597.5 g (p

232dialyzed children is well documented, managementfor optimal nutrition in children on PD requires strictdietary prescription (energy, proteins); dietary recall;monthly weight, length, head circumference (up to2 years), mid-arm circumference, skin-fold thicknessmeasurements; physical examination; and tests of biochemicaland hematologic parameters and dialysisadequacy (5,6).In the present prospective study, we used DEXAto evaluate the nutrition status of children on PD. Westudied bone mineral content and fat and lean bodymass; measured daily protein intake, daily energy intake,nitrogen balance, and dialytic parameters; andstudied the correlations between those variables.Patients and methodsWe performed prospective DEXA measurements in20 stable PD patients, all of them being treated asoutpatients at the Nephrology and Nutrition divisionsof Luis Calvo Mackenna Children’s Hospital. Thegroup included 12 boys and 8 girls whose mean agewas 5.84 years (range: 0.16 – 14.66 years) and whosemean duration on PD was 11 months (range: 2 –46 months). Underlying renal disorders included renaldysplasia (n = 10), reflux nephropathy (n = 3),hemolytic uremic syndrome (n = 1), obstructive uropathy(n = 1), chronic glomerulonephritis (n = 4),and an unknown disorder (n = 1). At the start of thestudy, 11 patients were on continuous ambulatory PD,and 9 were on automated PD. Four patients had noresidual renal function. Patients with fever, infections,nephrotic syndrome, gastrointestinal absorption disturbances,steroid treatments, endocrine diseases, geneticsyndromes, and compliance or behavioraldisturbances were excluded. The study protocol wasevaluated and approved by the ethics committee ofthe hospital, and written informed consent was obtainedfrom all parents before the study was initiated.Each month, we evaluated anthropometry, dietaryintake, nitrogen balance, serum bicarbonate, and dialysisdose. Whole-body DEXA was performed every6 months, and a peritoneal equilibration test (PET)was performed at the start of the study.Whole-body DEXAThe DEXA examinations were performed using aLunar DPX-L 7660 densitometer (Lunar RadiationCorporation, Madison, WI, U.S.A.). We obtained bonemineral content (BMC), lean body mass (LBM), andAzocar et al.fat body mass (FBM) in kilograms from the DEXAby using pediatric software for children with a weightless than 30 kg. All measurements were performed andanalyzed by the same investigator.AnthropometryWith the patient in minimum clothing, weight wasmeasured on a mechanical Seca scale (Seca Corporation,Hamburg, Germany) of 0.1 kg precision and150 kg capacity. All children on PD were weighedwith a known dialysate volume in the peritoneal cavity,and the weight of the solution was deducted fromthe observed weight. Height was measured with 1 mmprecision. All measurements were performed by thesame investigator.Dietary intakeOnce each month, 24-hour-recall and a food frequencyquestionnaire were used to estimate intake of energy,macronutrients, and micronutrients. Usual portionswere obtained from earlier studies plus food weighingduring the interview when necessary. A Chileanfood database stored in an Excel spreadsheet(Microsoft Corporation, Redmond, WA, U.S.A.) wasused for the calculation. A nutritionist obtained theinformation. Food intake adequacy was compared withDialysis Outcomes Quality Initiative (DOQI) guidelinesfor energy and protein requirements (5). Calciumand phosphorus intakes were compared with U.S.Recommended Dietary Allowances [RDA (7)].Nitrogen balance studiesBlood samples and 24-hour dialysate and urine werecollected on an outpatient basis. To avoid generationof urea secondary to bacterial activity, thimerosal wasadded to urine and dialysate samples. All samplesobtained under noncompliance conditions were discarded.Total protein and albumin (turbidimetric assay)were measured in plasma, urine, and dialysate.Dialysis doseWe calculated weekly Kt/V urea, both peritoneal andresidual using the equationKt/V urea = [24-h dialysate volume (L) × D/P urea× 7] / [0.60 × weight (kg)]Dialysis dose was prescribed to meet a minimumweekly Kt/V of 2 as specified in the DOQI guidelines

Body Composition in Children on PD(8), but no attempt was made to define a maximumKt/V value in our patients.Peritoneal equilibration testThe PET was performed according to a previouslypublished protocol (9,10). Briefly, a standardized volume(1100 mL/m 2 body surface area) of Dianeal 2.5%solution (Baxter Healthcare SA, Castlebar, Ireland)was instilled into the peritoneal cavity, and dialysatesamples were taken from the overnight exchange bagat 0, 120, and 240 minutes. A serum sample was takenat 120 minutes. Results were analyzed for the dialysate-to-plasma(D/P) creatinine and final-to-initialdialysate (D/D 0) glucose equilibration ratios at 4 hours,and each patient was categorized as a high, highaverage,low-average, or low transporter accordingto pediatric values published by Warady et al. (9).Biochemical measurementsWe obtained plasma measurements of bicarbonate(mEq/L, by bromcresol blue), phosphate (mg/dL, byphosphomolybdate complex colorimetry at 340 nm),calcium (by the cresolphthalein complexone method),alkaline phosphatase (by 4-nitrophenyl phosphate),and hemoglobin (by cyanmethemoglobin).Statistical analysisMeans, standard deviations, correlation coefficients,and t-tests were performed using Excel 5.0 (MicrosoftCorporation) and Statistica for Windows, version 4.5(StatSoft, Tulsa, OK, U.S.A.). Values of p < 0.05 wereaccepted as statistically significant.ResultsBody compositionBetween the start of the protocol and month 6, the20 patients evaluated by DEXA showed an increasein BMD to 0.769 ± 0.174 g/cm 2 from 0.747 ± 0.166 g/cm 2 , p < 0.05. The BMC in the group also increasedto 680.3 ± 666.1 g from 632.6 ± 597.5 g, p < 0.01.The mean BMD Z score at the beginning of thestudy in patients older than 4 years (n = 11) was –0.69(range: 0.3 to –2.2). The mean BMD Z score for those11 patients showed a significant increase to –0.35 atmonth 6. The FBM and FFM also increased, but withoutreaching statistical significance.The patients’ DPI showed a negative correlationwith BMD, BMC, and FFM (p < 0.05; Table I).233AnthropometryThe mean Z score for height/age was –2.17 (range:–4.75 to –0.3) at the start of the study, and –2.14 (range:–3.98 to –0.2) at month 6 [p = nonsignificant (NS)].The Z score for weight/age was –1.6 (range: –3.15 to–0.39) and –1.94 (range: –2.25 to 0.39) at the sametime periods (also p = NS).Dietary intakeMost of the patients showed a caloric intake abovethe RDA recommendations (mean values: 115.11% ±37.21% at month 1 and 108.16% ± 35.84% atmonth 6). In addition, the patients’ DPI exceeded theDOQI (5) recommendations (mean values: 144.77% ±48.74% at month 1 and 140.85% ± 52.13% atmonth 6, p = NS). Table II shows other dietary intakevalues.The patients’ mean DPI was 3.32 ± 1.6 g/kg/dayat the beginning of the study and 3.3 ± 1.3 g/kg/dayat month 6 (p = NS). A comparison of DPI versus bicarbonateshowed a negative correlation at the beginningof the study (r = –0.46, p < 0.05), but only atendency toward a negative correlation at month 6.Nitrogen balance studiesAll patients showed a positive NB initially and atmonth 6 of follow-up. Initially, mean DPI was 3.32 ±1.05 g/kg/day, and mean daily protein losses were1.19 ± 0.47 g/kg/day, for a mean net protein balanceof +2.1 g/kg/day. At month 6 of the study, mean DPIwas 3.30 ± 1.7 g/kg/day, and mean daily protein losseswere 1.7 ± 0.47 g/kg/day, for a net protein balance of+1.6 g/kg/day. We observed no difference in the proteinbalance between month 1 and month 6 of thestudy. We found a negative correlation between BNand the parameters BMD, FBM, and FFM (r = –0.8,r = –0.55, and r = –0.7 respectively; p < 0.05).Dialysis doseThe mean weekly total Kt/V urea was 3.31 ± 1.1 atthe beginning of the study and 2.57 ± 1.53 at month 6.The mean weekly peritoneal and residual Kt/V ureavalues were, respectively, 1.7 ± 0.81 and 1.5 ± 1.24 atthe beginning of the study, and 1.6 ± 0.58 and 1.5 ±1.18 at month 6.Peritoneal equilibration testThe mean 4-hour D/P creatinine was 0.78 ± 0.02 initiallyand 0.74 ± 0.13 at month 6 (p = NS). The mean

234TABLE IEvaluation of body composition by dual-energy X-ray absorptiometry in 20 children during peritoneal dialysisAzocar et al.Month 1 Month 6 p ValueBMC (g) 632.6 (32–2066) 680.3 (118–2227)

Body Composition in Children on PDIn renal failure, growth is acknowledged to be influencedby a variety of endocrine, nutritional, andmetabolic factors. The impact of dialysis dose ongrowth remains undetermined (15,16). Thus, to obtaina more detailed nutrition assessment and followupin CRF patients, it could well be imagined thatDEXA could be used as a complementary method ofassessing body composition, as suggested by the adhoc European committee on the assessment of growthand nutrition status in children on chronic PD (6).The reproducibility of DEXA measurements isexcellent: 1.2% for total fat-free and fat mass, and0.5% for bone mineral content. The precision is 1.0%and 2.0% for FFM and fat mass respectively. The fatmass derived from DEXA measurements correlateswell with the fat mass determined by hydrodensitometryand total-body 40 K. A limitation of DEXA isthat it does not measure total body water (TBW); instead,an assumption is made that TBW is 73.2% ofFFM. However, that assumption could result in anunderestimation of protein mass in underhydrated individualsand an overestimation of protein mass inoverhydrated individuals (4,11).A limitation of the present study is a lack of localreference values. As a result, we had to compare ourresults with the NHANES (National Health and NutritionExamination Survey) curves with SDS for BMDfor whole-body DEXA for children under 4 years ofage (17). The same is true for FFM and FBM. Thatbias must be taken in account when the data presentedhere are discussed.In terms of controlled dialysis and nutrition, weobserved a significant increase in bone mineralization:at 6 months of follow-up, BMD had risen to0.769 ± 0.174 g/cm 2 from 0.747 ± 0.166 g/cm 2 , andBMC had risen to 680.3 ± 666.1 g from 632.6 ±597.5 g. The BMD Z score is available from 4 yearsof age, and, in our patients older than 4 years (n =11), we found a significant increase to –0.35 from–0.69 (range: 0.3 to –2.2) during the observation period.An increase in FBM and FFM that did not reachstatistical significance was also observed.Most of the patients showed a daily caloric intakehigher than the RDA (mean of 115.11% ± 37.21% forenergy and 108.16% ± 35.84% for protein). Valuesfor DPI were higher than the DOQI recommendations(144.77% ± 8.74% at month 1 and 140.85% ± 52.13%at month 6, p = NS). But despite the high dietary intake,we did not see catch-up growth in all patients.235Recent reports have identified certain factors that couldinterfere with control of protein turnover in CRF patientsand therefore interfere with growth. Those factorsinclude acidosis, inflammation, and resistance toanabolic hormones (18).Schaefer et al., (19) observed a significant negativecorrelation between delta height SDS and thecreatinine equilibration rate in the initial study PET(r = –0.31, p < 0.05). Multiple regression analysis confirmeda negative effect of the high transport state (partialr 2 = 0.07) on delta height SDS. In the present study,it is interesting that we found a negative correlationbetween the mean 4-hour D/P creatinine and both theBMD and FFM parameters (p < 0.05), suggesting forthe first time that a high transport state is an adverserisk factor for nutrition status in children on PD.ConclusionsIn terms of positive NB and controlled Kt/V, we observedan increase in bone mineralization within a 6-month period of follow-up. A high protein intakeseems to negatively affect acid–base status, bone mineralization,and FFM. We also observed that a hightransport state, as measured by 4-hour D/P creatinine,may adversely affect the fat and mineral content ofthe body.AcknowledgmentThis study was supported by research grantFONDECYT 1010632.References1 Schaefer F, Wuhl E, Feneberg R, Mehls O, ScharerK. Assessment of body composition in children withchronic renal failure. Pediatr Nephrol 2000; 14:673–8.2 Warady B. Optimizing dialysis in pediatric patients.In: Nissenson AR, Fine RN, Gentile DE, eds. Clinicaldialysis. 2nd ed. Norwalk, CT: Appleton and Lange;1990: 189–202.3 Warady B, Alexander S, Watkins S, Kohaut E,Harmon W. Optimal care of the pediatric end-stagerenal disease patient on dialysis. Am J Kidney Dis1999; 33:567–83.4 Zemel B, Riley E, Stallings V. Evaluation of methodologyfor nutritional assessment in children: anthropometry,body composition, and energy expenditure.Annu Rev Nutr 1997; 17:211–35.5 Clinical practice guidelines for nutrition in chronicrenal failure. K/DOQI, National Kidney Foundation.

236Am J Kidney Dis 2000; 35(Suppl 2):S5–123.6 Coleman JE, Edefonti A, Watson AR on behalf of theEuropean Paediatric Peritoneal Dialysis WorkingGroup. Guidelines by an ad hoc European committeeon the assessment of growth and nutrition status inchildren on chronic peritoneal dialysis [Online].[Available at: http://www.multi-med.com/pdigifs/pdi213/coleman.pdf; accessed June 24, 2004]7 United States, National Research Council, NationalInstitutes of Health, Subcommittee on the 10th editionof the RDAs. Recommended dietary allowances.10th ed. Washington: National Academy Press; 1989.8 National Kidney Foundation. NKF–DOQI clinicalpractice guidelines for peritoneal dialysis adequacy.Am J Kidney Dis 1997; 30(Suppl 2):S86–8.9 Warady B, Alexander S, Hossli S, et al. Peritonealmembrane transport function in children receivinglong-term dialysis. J Am Soc Nephrol 1996;7:2385–91.10 Twardowski Z. Clinical value of standardized equilibrationtests in CAPD patients. Blood Purif 1989;7:95–108.11 Pichard C, Kyle UG. Body composition measurementsduring wasting diseases. Curr Opin Clin NutrMetab Care 1998; 1:357–361.12 Feber J, Cochat P, Lebl J, et al. Body composition inchildren receiving recombinant human growth hormoneafter renal transplantation. Kidney Int 1998;54:951–5.13 Cochat P, Braillon P, Feber J, et al. Body compositionin children with renal disease: use of dual energy X-Azocar et al.ray absorptiometry. Pediatr Nephrol 1996; 10:264–8.14 Feber J, Braillon P, David L, Cochat P. Body compositionin children after renal transplantation. Am JKidney Dis 2001; 38:366–70.15 Chadha V, Blowey DL, Warady BA. Is growth avalid outcome measure of dialysis clearance in childrenundergoing peritoneal dialysis? Perit Dial Int2001; 20(Suppl 3):S179–84.16 Neu AM, Ho PL, McDonald RA, Warady BA.Chronic dialysis in children and adolescents. The2001 NAPRTCS Annual Report. Pediatr Nephrol2002; 17:656–63.17 Mussolino M, Looker A, Madans J, Langlois J,Orwoll EM. Risk factors for hip fracture in whitemen: the NHANES I Epidemiologic Follow-upStudy. J Bone Miner Res 1998; 13:918–24.18 Mitch W. Insights into the abnormalities of chronicrenal disease attributed to malnutrition. J Am SocNephrol 2002; 13(Suppl 1):S22–7.19 Schaefer F, Klaus G, Mehls O. Peritoneal transportproperties and dialysis dose affect growth and nutritionalstatus in children on chronic peritoneal dialysis.Mid-European Pediatric Peritoneal DialysisStudy Group. J Am Soc Nephrol 1999; 10:1786–92.Corresponding author:Marta A. Azocar, MD, El Vergel 2828, Appt 603,Providencia, Santiago 6650813 Chile.E-mail:martitaazocar@hotmail.com