Disparities in treatment and outcome of kidney replacement therapy in children with comorbidities: an ESPN/ERA Registry study.

Background: Data on comorbidities in children on kidney replacement therapy (KRT) are scarce. Considering their high relevance for prognosis and treatment, this study aims to analyse the prevalence and implications of comorbidities in European children on KRT. Methods: We included data from patients <20 years of age when commencing KRT from 2007 to 2017 from 22 European countries within the European Society of Paediatric Nephrology/European Renal Association Registry. Differences between patients with and without comorbidities in access to kidney transplantation (KT) and patient and graft survival were estimated using Cox regression. Results: Comorbidities were present in 33% of the 4127 children commencing KRT and the prevalence has steadily increased by 5% annually since 2007. Comorbidities were most frequent in high-income countries (43% versus 24% in low-income countries and 33% in middle-income countries). Patients with comorbidities had a lower access to transplantation {adjusted hazard ratio [aHR] 0.67 [95% confidence interval (CI) 0.61-0.74]} and a higher risk of death [aHR 1.79 (95% CI 1.38-2.32)]. The increased mortality was only seen in dialysis patients [aHR 1.60 (95% CI 1.21-2.13)], and not after KT. For both outcomes, the impact of comorbidities was stronger in low-income countries. Graft survival was not affected by the presence of comorbidities [aHR for 5-year graft failure 1.18 (95% CI 0.84-1.65)]. Conclusions: Comorbidities have become more frequent in children on KRT and reduce their access to transplantation and survival, especially when remaining on dialysis. KT should be considered as an option in all paediatric KRT patients and efforts should be made to identify modifiable barriers to KT for children with comorbidities.

Sodium intake and urinary losses in children on dialysis: a European multicenter prospective study.

BACKGROUND: Sodium (Na) balance is unexplored in dialyzed children. We assessed a simplified sodium balance (sNaB) and its correlates in pediatric patients receiving maintenance dialysis. METHODS: Patients < 18 years old on hemodialysis (HD) or peritoneal dialysis (PD) in six European Pediatric Dialysis Working Group centers were recruited. sNaB was calculated from enteral Na, obtained by a 3-day diet diary, Na intake from medications, and 24-h urinary Na (uNa). Primary outcomes were systolic blood pressure and diastolic blood pressure standard deviation scores (SBP and DBP SDS), obtained by 24-h ambulatory blood pressure monitoring or office BP according to age, and interdialytic weight gain (IDWG). RESULTS: Forty-one patients (31 HD), with a median age of 13.3 (IQR 5.2) years, were enrolled. Twelve patients (29.3%) received Na-containing drugs, accounting for 0.6 (0.7) mEq/kg/day. Median total Na intake was 1.5 (1.1) mEq/kg/day, corresponding to 60.6% of the maximum recommended daily intake for healthy children. Median uNa and sNaB were 0.6 (1.8) mEq/kg/day and 0.9 (1.7) mEq/kg/day, respectively. The strongest independent predictor of sNaB in the cohort was urine output. In patients receiving HD, sNaB correlated with IDWG, pre-HD DBP, and first-hour refill index, a volume index based on blood volume monitoring. sNaB was the strongest predictor of IDWG in multiple regression analysis (ß = 0.63; p = 0.005). Neither SBP SDS nor DBP SDS correlated with sNaB. CONCLUSIONS: Na intake is higher than uNa in children on dialysis, and medications may be an important source of Na. sNaB is best predicted by urine output in the population, and it is a significant independent predictor of IDWG in children on HD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Low dialysate sodium in children and young adults on maintenance hemodialysis: a prospective, randomized, crossover study.

BACKGROUND: The optimal dialysate sodium concentration (dNa) in children on hemodialysis (HD) is unknown. The aim of this study was to compare the effect on interdialytic weight gain (IDWG) and blood pressure (BP) of a low (135 mmol/l) and standard dNa (138 mmol/l) in children and young adults on maintenance HD. METHODS: This prospective single-blind randomized crossover study consisted of a randomized sequence of two phases: "standard dNa" of 138 mmol/L and "low dNa" of 135 mmol/L. Each phase lasted 4 weeks. Inclusion criteria were age < 25 years, hypertension, pre-HD serum Na (sNa) ≥ 130 mmol/L, and occurrence of symptoms in less than 25% of sessions. Primary outcomes were pre-HD systolic and diastolic BP and IDWG. RESULTS: Fifteen patients were recruited, mean age 17.8 ± 4.4 years. Pre-HD SBP and DBP were not different between the two treatments. Mean IDWG was significantly lower with low dNa than with standard dNa: 2.12 ± 1.39% vs. 2.77 ± 1.53%, respectively (p = 0.008). The first-hour refill index (a volume index based on blood-volume monitoring) was significantly lower with dNa 135 mmol/L (p = 0.018). The mean Na gradient (dNa-sNa) was - 2.53 ± 2.4 mmol/L with dNa 135 mmol/L and 0.17 ± 2.8 mmol/L with dNa 138 mmol/L (p = 0.0001). The incidence of symptomatic sessions was similar (1.0% vs. 1.0%). CONCLUSIONS: In a selected population of hypertensive pediatric and young adult HD patients, a dNa of 135 mmol/L was associated with a significant reduction of IDWG compared with a dNa of 138 mmol/L. Furthermore, long-term studies are needed to investigate the effect of lowering dNa on BP. A higher resolution version of the Graphical abstract is available as Supplementary information.

Nutritional status and volume control in adolescents on chronic hemodialysis.

BACKGROUND: Pediatric patients on maintenance hemodialysis (HD) are at risk of both malnutrition and fluid overload. This pilot study aimed to assess correlates of normalized protein catabolic rate (nPCR) in adolescents on chronic HD, in particular fluid status markers. METHODS: All patients aged 10-18 years on chronic HD in our center between 2017 and 2019 were enrolled. For each patient, mean nPCR was calculated and correlations with the following parameters investigated: dry body weight change in subsequent 3 months in kg (∆BW) and percentage of BW (∆BW%), change in body mass index (∆BMI), preHD systolic and diastolic blood pressure (SBP, DBP), residual urine output, biochemistry, and blood volume monitoring-derived first hour refill index (RI), calculated as ratio between ultrafiltration rate and reduction in relative blood volume in first hour of dialysis. RESULTS: Seventy-nine nPCR determinations were collected in 23 patients, median age 14.8 years. nPCR significantly correlated with ∆BW, ∆BW%, ∆BMI, spKT/V, and preHD serum creatinine, and negatively correlated with age, DBP SDS (r=-0.466, p=0.025) and RI (r=-0.435, p=0.043). RI was significantly higher in patients with nPCR <1 than those with nPCR above this threshold: 3.2 (1.9-4.7) vs. 1.4 (0.7-1.8) ml/kg/h/% (p=0.021). At multivariable analysis, nPCR remained positively correlated with creatinine and spKt/V, and inversely correlated with RI. CONCLUSIONS: nPCR is a significant predictor of weight change in adolescents on maintenance HD, and seems associated with creatinine and dialysis adequacy. Inverse correlation with RI suggests possible associations between malnutrition and fluid overload, but larger prospective studies are needed to confirm this. A higher resolution version of the Graphical abstract is available as Supplementary information.

Resident foreign patients receive adequate dialysis but fewer preemptive transplantations: data from the Italian pediatric dialysis registry.

BACKGROUND: Sociocultural issues play a key role in children needing kidney replacement therapy (KRT). METHODS: Data of incident patients < 18 years treated with chronic dialysis or preemptive kidney transplantation (pTx) between 2007 and 2016 were retrospectively collected from the Italian Pediatric Dialysis Registry; KRT modality and outcome were compared between patients with at least one non-Italian parent ("resident foreign patients," RFPs) and those from native parents ("domestic patients," DPs) and between the quinquennium 2007-2011 (period 1) and 2012-2016 (period 2). RESULTS: We included 448 children (26.8% RFPs). The percentage of RFPs increased from 23 to 30.3% (p = 0.08) from periods 1 to 2. They were younger (6.7 vs. 9.4 years, p = 0.025) and less often treated with pTx (3.3 vs. 13.4%, p = 0.009) than DPs. The percentage of pTx increased from period 1 to 2 in RFPs only (8.4-18.6%, p = 0.006). Independent predictors of a lower probability of pTx were lower age, belonging to RFPs group, starting KRT in period 1 and focal segmental glomerulosclerosis or glomerulopathy as primary kidney disease. Peritoneal dialysis was the preferred dialysis modality in both groups. Age, primary kidney disease, and center size were independently associated with dialysis modality choice. Patient survival, waiting time to Tx, and dialysis modality survival were not different between the two groups. CONCLUSIONS: The proportion of patients receiving KRT born from immigrant families increased in recent years in Italy. They were younger and less often treated with pTx than domestic patients. In case of dialysis, the outcome was not different between the two groups. Graphical abstract.

Haemodiafiltration use in children: data from the Italian Pediatric Dialysis Registry.

BACKGROUND: High volume haemodiafiltration (HDF) is associated with better survival than conventional haemodialysis (HD) in adults, but data concerning its use in children are lacking. The aim of this study was to assess the prevalence of paediatric HDF use and its associated factors in recent years in Italy. METHODS: We retrospectively reviewed the files of patients from the Italian Pediatric Dialysis Registry's database who were registered between January 1, 2004 and December 31, 2016 and treated with extracorporeal dialysis for at least 6 months, looking in particular at modality and its associated factors. RESULTS: One hundred forty-one out of 198 patients were treated exclusively with bicarbonate HD (71.2%), 57 with HDF (28.8%). Patients treated with HDF were younger (median 9.7 vs 13.2 years, p = 0.0008), were less often incident patients (52.6% vs 75.9%, p = 0.0031), had longer duration of the HD cycle (26.9 vs 20.8 months, p = 0.0036) and had a longer time to renal transplantation (32 vs 25 months, p = 0.0029) than those treated with bicarbonate HD only. The percentage of patients treated with HDF increased with dialysis vintage (16.9% at 6 months, 38.1% after more than 2 years of dialysis). The use of HDF was stable over time and was more common in the largest centres. CONCLUSIONS: Over the observation period, HDF use in Italy has been limited to roughly a quarter of patients on extracorporeal dialysis, in particular to those with high dialysis vintage, younger age or a long expected waiting time to renal transplantation.

A simple prognostic index for Shigatoxin-related hemolytic uremic syndrome at onset: data from the ItalKid-HUS network.

Shigatoxin Escherichia coli-related hemolytic uremic syndrome (eHUS) is a severe thrombotic microangiopathy (TMA) burdened by life-threatening complications and long-term sequelae. Since hemoconcentration is associated with worse outcome, we tried to develop a reliable and easy-to-calculate index for predicting complications and sequelae based on hemoglobin (Hb) at presentation. The first laboratory examinations with signs of TMA in eHUS patients were analyzed in relation to the outcomes with the receiver operating characteristic curves and their areas under the curve (AUC) for Hb and creatinine (sCr). A total of 197 eHUS patients were identified of whom 24% did not have anemia at presentation. Hb level was the best predictor of a poor outcome (AUC 0.67) but the combination of Hb with sCr, in the formula [(Hb in g/dL + (sCr in mg/dL × 2)], showed an even better AUC of 0.75. The described scoring system was also strongly associated and predictive of all complications and health care needs (8% of patients with scoring > 13 died or entered a permanent vegetative state compared with 0% of those with ≤ 13).Conclusion: The presented score is a simple and early predictor of both short- and long-term outcomes and identifies patients who should undergo rapid volume expansion to counteract hemoconcentration, the spreading of microvascular thrombosis, and the consequent increased organ damage. What is Known: • In eHUS, hemoconcentration is associated with worse short- and long-term outcome. • A prognostic index to identify patients at higher risk for complications at presentation is not available. What is New: • We developed a simple and early prognostic index for eHUS outcome with the combination of Hb and sCr at onset, in the following formula [(Hb in g/dL + (sCr in mg/dL × 2)]. • The proposed HUS Severity Score can promptly identify patients with good outcome and those with high risk of worse short- and long-term outcome.

The first hour refill index: a promising marker of volume overload in children and young adults on chronic hemodialysis.

BACKGROUND: Volume overload is a known risk factor for cardiovascular complications in children on hemodialysis (HD), but a measurable index of volume overload is still lacking. METHODS: We propose a novel index of pre-HD volume overload based on blood volume (BV) monitoring, the first hour refill index (RI), calculated as the ratio between the ultrafiltration rate indexed for body weight during the first HD hour and the percent BV change at the first hour of the treatment. This parameter was retrospectively calculated in 121 sessions in 11 oligoanuric children and young adults on chronic HD, with median age 14.3 years (range 5.4-22.4), and its association with left-ventricular mass index, pre-HD blood pressure, and number of antihypertensive medications was evaluated. RESULTS: The median RI was 2.07 ml/kg/h/%. There was a significant correlation between RI and median LVMI (r 0.66, p = 0.028), which was 53.4 g/m2.7 (45.7-64) in patients with a median RI > 2, and 36.6 g/m2.7 (24.9-47) in those with a median RI < 2 ml/kg/h/% (p = 0.01). The number of antihypertensive drugs per patient was significantly higher in patients with a RI > 2 than in those with a RI < 2 ml/kg/h/% (three vs one per patient; p = 0.02) while blood pressure was not significantly different between the two groups. CONCLUSIONS: The ratio between the ultrafiltration rate per body weight and the BV change during the first hour of a HD session could be a promising index of refill capacity and pre-HD volume overload in children and young adults on chronic HD.

Plasma-exchange in pediatric patients: a single-center experience.

BACKGROUND: Plasma-exchange (PEX) has been well described in pediatrics, but most of the current indications are derived from adult experience. Aim of the study was to review the PEX treatments in our Unit over a six-year period. METHODS: Three hundred and seventy-seven PEX sessions were performed in 38 patients (median age 12.1 years, range 0.6-20.5). Double-needle and single-needle PEX combined with hemodialysis and PEX combined with ultrafiltration were performed in 9, 1 and 3 patients respectively. The most common indications to PEX were atypical hemolytic uremic syndrome (aHUS, 9 patients), focal segmental glomerulosclerosis (FSGS, 9 cases), antibody mediated rejection (AMR) in renal transplant (rTx) recipients (8 patients) and hyperimmunization in patients waiting for rTx (4 cases). RESULTS: We treated five patients with aHUS on native kidneys with PEX only, with complete remission in 4/6 recurrences; PEX was also successfully used to prevent HUS relapse in three patients undergoing rTx. Only one partial remission was obtained in four patients with FSGS on native kidneys, by means of treatment protocols based on PEX and immunosuppressants; conversely, a partial remission was observed in 6/6 patients with recurrence of FSGS on rTx. Immunosuppressive protocols combined with PEX proved useful in sensitized cadaveric rTx recipients (2/4 successfully transplanted), but failed in 6 patients with chronic AMR. As regards complications, two severe adverse reactions occurred: an anaphylactic shock after the use of albumin and an abdominal hemorrhage. CONCLUSIONS: PEX is a relatively safe procedure in children. Pediatric patients with aHUS, recurrent FSGS and sensitized rTx recipients seem to benefit from treatment strategies including PEX.

Chronic haemodialysis in small children: a retrospective study of the Italian Pediatric Dialysis Registry.

BACKGROUND: Chronic haemodialysis (HD) in small children has not been adequately investigated. METHODS: This was a retrospective investigation of the use of chronic HD in 21 children aged <2 years (n = 12 aged <1 year) who were registered in the Italian Pediatric Dialysis Registry. Data collected over a period of >10 years were analysed. RESULTS: The median age of the 21 children at start of HD was 11.4 [interquartile range (IQR) 6.2-14.6] months, and HD consisted mainly of haemodiafiltration for 3-4 h in ≥4 sessions/week. A total of 51 central venous catheters were placed, and the median survival of tunnelled and temporary lines was 349 and 31 days, respectively (p < 0.001). Eight children (38 %) showed evidence of central vein thrombosis. Although 19 % of patients received growth hormone and 63.6 % received enteral feeding, the weight and height of these patients remained suboptimal. During the HD period the haemoglobin level increased in all patients, but not to normal levels (from 8.5 to 9.6 g/dl) despite erythropoietin administration (503-600 U/kg/week). The hospitalisation rate was 1.94/patient-year. Seventeen patients underwent renal transplantation at a median age of 3.0 years. Four patients, all affected by severe comorbidities, died during follow-up (in 2 cases due to absence of a vascular access). The 5- and 10-year cumulative survival was 82.4 and 68.7 %, respectively. CONCLUSIONS: Extracorporeal dialysis is feasible in children aged <2 years, but comorbidities, vascular access, growth and anaemia remain major concerns.

Vitamin K antagonists in children with central venous catheter on chronic haemodialysis: a pilot study.

BACKGROUND: To date, no study has investigated the use of vitamin K antagonists (VKA) in children undergoing chronic haemodialysis (HD) with a central venous catheter (CVC). METHODS: Consecutive patients aged <18 years with a newly placed tunnelled CVC for chronic HD were enrolled over a 3-year period. Children with active nephrotic syndrome or a history of venous thrombosis received warfarin (VKA group) with therapeutic target international normalised ratios of between 2.0 and 3.0. Patients at standard risk of CVC malfunction were not treated with VKA (standard group). The primary end-point was overall CVC survival. RESULTS: The VKA group consisted of nine patients (median age 10.6 years; range 1.2-15.3 years) with 11 CVC, and the standard group comprised eight patients (11.8 years; 6.1-17.3 years) with ten CVC. The 6- and 12-month CVC survival was significantly longer in the VKA group than in the standard group (100 vs. 60 % and 83.3 vs. 16.7 %, respectively; p < 0.05), with a median survival of 369 and 195 days, respectively (p < 0.05). None of the CVC in the VKA group required removal due to malfunction, as compared to four in the standard group. No major bleeding episodes occurred in either group. CONCLUSIONS: Therapy with VKA would appear to be safe in children on chronic HD and may improve CVC survival in patients at increased risk of CVC thrombosis.

Interdialytic weight gain in oligoanuric children and adolescents on chronic hemodialysis.

BACKGROUND: Little is known about the clinical impact of interdialytic weight gain (IDWG) on oligoanuric children undergoing chronic hemodialysis (HD). METHODS: We retrospectively assessed IDWG, left ventricular mass index (LVMI) and its changes (ΔLVMI), pre-HD systolic and diastolic blood pressure (DBP), residual urine output, Kt/V, the frequency of intradialytic symptoms, normalized protein catabolic rate, and the 3-month change in the dry weight of 16 hemodialyzed oligoanuric patients with a median age of 14.8 years (range 5.0-17.9). RESULTS: There was a significant correlation between IDWG and median LVMI (r 0.55, p = 0.026), which was 27.3 g/m(2.7) (22.5-37.6) in the patients with a median IDWG of <4 %, and 44.3 g/m(2.7) (28.2-68.7) in those with a median IDWG of >4 % (p = 0.003). None of the four patients with an IDWG of <4 % showed left ventricular hypertrophy, compared with 10 of the 12 patients (83.3 %) with an IDWG of >4 % (p = 0.003); the former also had a better median ΔLVMI (-33.5 % vs -13.0 %; p = 0.02) and a lower median DBP sds (0.24 vs 1.72, p = 0.04). CONCLUSIONS: There is a significant correlation between IDWG and LVMI in pediatric oligoanuric patients on chronic HD: those with an IDWG of >4 % are at a higher risk of left ventricular hypertrophy.

Reduction in catheter-related infections after switching from povidone-iodine to chlorhexidine for the exit-site care of tunneled central venous catheters in children on hemodialysis.

Only a few studies have investigated the optimal exit site management of tunneled central venous catheters (CVCs) in pediatric patients on chronic hemodialysis (HD). The aim of this study was to assess the efficacy of chlorhexidine solutions and a 5% povidone-iodine solution on the incidence of CVC-related infections in children on HD. The incidence of exit-site infection (ESI), tunnel infection (TI), and bloodstream infection (BSI) was assessed in two groups of tunneled CVCs. The iodopovidone group consisted of 14 CVCs used between 1 January 2011 and 30 June 2012 in 10 children, whose median age at the time of CVC placement was 11.8 years (range 1.2-19.2): 5% povidone-iodine was used for CVC exit-site care. From 1 August 2012 to 31 January 2014, 0.5% chlorhexidine gluconate/70% isopropyl alcohol was used for the exit site, and 2% chlorhexidine gluconate/70% isopropyl alcohol spray for the hub in 13 CVCs was used in 10 patients (chlorhexidine group), whose median age at the time of CVC placement was 10 years (range 1.2-19.2). Ten episodes of ESI were diagnosed in the iodopovidone group (incidence 3.4/1000 CVC days), and only one in the chlorhexidine group (incidence 0.36/1000 CVC days, P = 0.008). One TI was observed in the iodopovidone group (0.34/1000 CVC days), and none in the chlorhexidine group. The incidence of BSIs decreased from 1.7/1000 CVC days (5 cases) to 0.36/1000 CVC days (1 case, P = 0.06) after switching to chlorhexidine. Two CVCs were lost due to CVC-related infections in the iodopovidone group, whereas no CVC was lost due to infections in the chlorhexidine group. In comparison with 5% povidone-iodine, the use of chlorhexidine gluconate was associated with a reduction in the incidence of ESI, TI, and BSI in children on HD.

Possible molecular mechanisms linking air pollution and asthma in children.

BACKGROUND: Air pollution has many effects on the health of both adults and children, but children's vulnerability is unique. The aim of this review is to discuss the possible molecular mechanisms linking air pollution and asthma in children, also taking into account their genetic and epigenetic characteristics. RESULTS: Air pollutants appear able to induce airway inflammation and increase asthma morbidity in children. A better definition of mechanisms related to pollution-induced airway inflammation in asthmatic children is needed in order to find new clinical and therapeutic strategies for preventing the exacerbation of asthma. Moreover, reducing pollution-induced oxidative stress and consequent lung injury could decrease children's susceptibility to air pollution. This would be extremely useful not only for the asthmatic children who seem to have a genetic susceptibility to oxidative stress, but also for the healthy population. In addition, epigenetics seems to have a role in the lung damage induced by air pollution. Finally, a number of epidemiological studies have demonstrated that exposure to common air pollutants plays a role in the susceptibility to, and severity of respiratory infections. CONCLUSIONS: Air pollution has many negative effects on pediatric health and it is recognised as a serious health hazard. There seems to be an association of air pollution with an increased risk of asthma exacerbations and acute respiratory infections. However, further studies are needed in order to clarify the specific mechanism of action of different air pollutants, identify genetic polymorphisms that modify airway responses to pollution, and investigate the effectiveness of new preventive and/or therapeutic approaches for subjects with low antioxidant enzyme levels. Moreover, as that epigenetic changes are inheritable during cell division and may be transmitted to subsequent generations, it is very important to clarify the role of epigenetics in the relationship between air pollution and lung disease in asthmatic and healthy children.

Intradialytic cycling in children and young adults on chronic hemodialysis.

BACKGROUND: Intradialytic exercise has been poorly investigated in pediatric patients on chronic hemodialysis (HD). The aim of this study was to assess the acceptability, safety and efficacy of intradialytic exercise in children and young adults on HD. METHODS: The intradialytic exercise program consisted of 30-min sessions of intra-HD exercise using a cycloergometer two to three times a week for 3 months. Study endpoints were the 6-min walking test (6MWT) distances, lung function, number of stands in the chair test, lower extremity strength (LES), anthropometry, dietary intake, dialysis adequacy, incidence of symptomatic sessions, biochemistry and left ventricular mass index. RESULTS: Ten pediatric patients with a median age of 15.3 (range 9.1-24.2) years were enrolled. Two of these underwent kidney transplantation; the remaining eight completed the study and adapted well to the exercise program. At the end of the 3-month study period, all patients had significantly improved results for the 6MWT (+4.9 %; p < 0.05), chair test (+19 %; p < 0.05) and LES (+29.3 %; p < 0.05). Pre-HD albumin, creatinine and total protein levels and post-HD creatinine levels had also significantly improved. The incidence of symptomatic sessions did not increase during the study period. No adverse events occurred. CONCLUSIONS: Based on our results, we conclude that a 30-min exercise program of intradialytic cycling is feasible for the majority of pediatric patients on chronic HD and will be well accepted. Such an exercise program can lead to a significant improvement in the exercise capacity of this patient population.

Correlates of exercise capacity in pediatric patients on chronic hemodialysis.

OBJECTIVE: Pediatric patients on chronic hemodialysis (HD) are at high risk of inactivity and poor physical fitness. The aim of this study was to assess the main correlates of exercise capacity in a cohort of children and young adults on chronic HD. METHODS: Twelve patients on chronic HD (median age 15.6 years; range 9.1-24.2) underwent a 6-minute walking test (WT), spirometry, a 1-minute chair stand test, and the measurement of lower extremity strength. Demographic data, anthropometry (dry weight, height, body mass index, and skinfold thickness, all expressed as standard deviation scores [SDS]), biochemistry (serum albumin, hemoglobin, creatinine, C-reactive protein, bicarbonate), bioimpedance analysis, HD adequacy indices (spKt/V and eKt/V), left ventricular mass index, and medications were also recorded. RESULTS: There was a significant correlation among the distance covered during the WT (median 552 m, range 186-670), forced vital capacity (87.8% of predicted, range 49.7-136), forced expiratory volume in 1 second (86.7%, range 54.7-126.7), and peak expiratory flow (75.5%, 49.7-105.1). All of these indices positively correlated with the weight SDS (r 0.69-0.85), pre-HD serum creatinine (0.57-0.77), and serum albumin (0.60-0.77) and negatively correlated with weekly erythropoietin dose per kilogram of body weight (from -0.64 to -0.83), with P values ranging from <.05 to <.0005. Lower extremity strength (median 11.5 kg, range 3-15) positively correlated with the number of stands at the chair stand test (median 33, range 18-47; r 0.73, P < .05) and serum albumin (r 0.83, P < .01). Distance at the WT, forced vital capacity, lower extremity strength, and the number of stands at the chair stand test all negatively correlated with C-reactive protein levels (r from -0.81 to -0.67, P < .05). CONCLUSION: Our findings show that protein-energy wasting and chronic inflammation are strongly correlated with the exercise capacity of children and young adults on chronic HD.

Adenovirus 36 infection and obesity.

The most important factors leading to fat accumulation in children are genetic inheritance, endocrine alterations, and behavioural/environmental causes. In addition, experimental animal studies have shown that infections due to various pathogens can lead to overweight and obesity conditions, and studies of humans have found that the incidence of seroconversion against some of these may be significantly more frequent in obese adults and children than in normal subjects. However, the results of these studies are not conclusive and, in some cases, have raised more questions than answers. We reviewed the literature concerning the role of adenovirus 36 (AD-36), the most widely studied infectious agent in animals and humans, because of its potential association with childhood obesity. The available evidence suggests that more studies are needed to evaluate whether or not the association between the presence of AD-36 antibodies and obesity is simply unrelated, and to verify whether there are subjects that have greater tendency to become obese because more easily susceptible to AD-36 infection or with a predisposition to suffer from persistent viral infection more easily leading to the development of obesity. If it is demonstrated that AD-36 does play a role in obesity, it will be important to investigate possible vaccines against the infection itself or antiviral drugs capable of inhibiting disease progression.