The role of basic nutritional research in pediatric liver disease : an historical perspective

The advent of liver transplantation for end-stage liver disease (ESLD) in children has necessitated a major rethink in the preoperative preparation and management from simple palliative care to active directed intervention. This is particularly evident in the approach to the nutritional care of these patients with the historical understanding of the nutritional pertubations in ESLD being described from a single pediatric liver transplant center. ESLD in children is a hypermetabolic process adversely affecting nutritional status, metabolic, and non-metabolic body compartments. There is a complex dynamic process affecting metabolic activity within the metabolically active body cell mass, as well as lipid oxidation during fasting and at rest, with other factors operating in conjunction with daily activities. We have proposed that immediately ingested nutrients are a more important source of energy in patients with ESLD than in healthy children, among whom energy may be stored in various body compartments.

Assessment of body composition in Sri Lankan children: Validation of a bioelectrical impedance prediction equation

Objective: To develop bioelectrical impedance analysis (BIA) equations to predict total body water (TBW) and fat-free mass (FFM) of Sri Lankan children. Subjects/Methods: Data were collected from 5- to 15-year-old healthy children. They were randomly assigned to validation (M/F: 105/83) and cross-validation (M/F: 53/41) groups. Height, weight and BIA were measured. TBW was assessed using isotope dilution method (D2 O). Multiple regression analysis was used to develop preliminary equations and cross-validated on an independent group. Final prediction equation was constructed combining the two groups and validated by PRESS (prediction of sum of squares) statistics. Impedance index (height2/impedance; cm2/Ω), weight and sex code (male = 1; female = 0) were used as variables. Results: Independent variables of the final prediction equation for TBW were able to predict 86.3% of variance with root means-squared error (RMSE) of 2.1l. PRESS statistics was 2.1l with press residuals of 1.2l. Independent variables were able to predict 86.9% of variance of FFM with RMSE of 2.7 kg. PRESS statistics was 2.8 kg with press residuals of 1.4 kg. Bland Altman technique showed that the majority of the residuals were within mean bias±1.96 s.d. Conclusions: Results of this study provide BIA equation for the prediction of TBW and FFM in Sri Lankan children. To the best of our knowledge there are no published BIA prediction equations validated on South Asian populations. Results of this study need to be affirmed by more studies on other closely related populations by using multi-component body composition assessment.

Current management of transitional feeding issues in preterm neonates born in Queensland, Australia

Background: Many preterm neonates display difficulty establishing suck-feeding competence in the weeks following birth. Ineffective management of transitional feeding issues may cause patient complications, and can contribute to increased length of stay. Aims: Given that many neonatal nurseries appear to vary in their neonatal feeding management practices, the aim of this study was to investigate and document the routine level of support and intervention currently provided for preterm neonates with transitional feeding issues across the various level II (special care) nurseries (SCNs) in Queensland, Australia. Methods: A questionnaire was mailed to all Queensland SCNs in 2005 (n = 36). The questionnaire contained a series of closed-choice and short-answer questions designed to obtain information from each SCN regarding their current practices for managing transitional feeding issues in preterm neonates. Results were confirmed during a follow-up phone call. Results: Responses were obtained from 29 SCNs (80.6%). None of these nurseries reported having any formal, written policies regarding the management of transitional feeding issues in preterm neonates. Wide variations were reported in relation to the suck-feeding assessments and interventions used by staff within the various SCNs. Of the 29 nurseries, 4 (13.8%) reported using checklists or assessments to judge readiness for suck-feeds, and 5 (17.2%) reported using pulse oximetry to judge tolerance of suck-feeding attempts. Eighteen SCNs (62.1%) reported offering some form of active intervention to assist neonates with transitional feeding issues, with the most common intervention techniques reported being non-nutritive sucking during tube feeds, pre-feeding oral stimulation, and actively pacing suck-feeds. Twenty-two SCNs (75.4%) reported having access to a lactation consultant to assist mothers with breastfeeding issues. Conclusions: Differences were reported in the routine management of transitional feeding issues in preterm neonates across the various SCNs in Queensland. It is suggested that evidence based guidelines need to be developed, and that, in order to do this, further research studies are required to determine current best practice, as well as to answer remaining questions. © 2008 Elsevier Ireland Ltd. All rights reserved.

Attainment of early feeding milestones in preterm neonates

Objective: This study aimed to document the ages at which preterm neonates commence suckle-feeds and attain exclusive suckle-feeding, as well as the time taken to transition from commencement of suckle-feeds to exclusive suckle-feeding. It was hypothesized that gestational age (GA) at birth and degree of neonatal morbidity would influence the timing of these early feeding milestones. Study Design: A chart review was conducted for all neonates born <37;0 weeks GA admitted to a tertiary level perinatal facility over a 12-month period (n=735). Complete data relating to attainment of feeding milestones were available on 472 neonates. Results: Correlation analysis indicated that both a low GA at birth and a high neonatal morbidity rating were statistically significantly correlated with an increased transition time from commencement of suckle-feeds to exclusive suckle-feeding. Cox regression indicated that both of these variables were statistically significant risk factors for a delayed GA at attainment of exclusive suckle-feeding. Conclusion: Preterm neonates who were less mature at birth and/or who displayed a greater degree of neonatal morbidity took longer to transition from starting suckle-feeds to achieving independent suckle-feeding, and were more mature at attainment of independent suckle-feeding.

Growth patterns in preterm infants born appropriate for gestational age

Aim: This study aimed to document the growth patterns of a contemporary cohort of preterm infants born appropriate for gestational age (AGA). It was hypothesised that preterm AGA (PT-AGA) infants would display poorer growth than full-term AGA (FT-AGA) infants. Methods: Sixty-four PT-AGA infants and 64 FT-AGA infants were assessed at 0, 4, 8 and 12 months of corrected age (CA). Measurements of weight and length were recorded at each of the specified ages. Centers for Disease Control and Prevention growth data were used to calculate Z-scores for weight and length based on CA. Results: The mean length and weight Z-scores of PT-AGA infants were found to be significantly less than those of FT-AGA infants at term, 4, 8 and 12 months of CA (P < 0.001). The mean weight Z-score of PT-AGA infants was found to be less than their mean length Z-score at each time point, though the differences were not significant. Conclusions: The results of this study suggest that PT-AGA infants are likely to display poorer growth than FT-AGA infants until at least 1 year of CA. Long-term growth monitoring in this population is recommended. © 2008 The Authors.

Dichotomy of food and inhalant allergen sensitization in eosinophilic esophagitis

Background: Eosinophilic esophagitis (EE) is an emerging condition where patients commonly present with symptoms of gastroesophageal reflux disease and fail to respond adequately to anti-reflux therapy. Food allergy is currently recognized as the main immunological cause of EE; recent evidence suggests an etiological role for inhalant allergens. The presence of EE appears to be associated with other atopic illnesses. Objectives: To report the sensitization profile of both food and inhalant allergens in our EE patient cohort in relation to age, and to profile the prevalence of other allergic conditions in patients with EE. Method: The study prospectively analyzed allergen sensitization profiles using skin prick tests to common food allergens and inhalant allergens in 45 children with EE. Patch testing to common food allergens was performed on 33 patients in the same cohort. Comorbidity of atopic eczema, asthma, allergic rhinitis and anaphylaxis were obtained from patient history. Results: Younger patients with EE showed more IgE and patch sensitization to foods while older patients showed greater IgE sensitization to inhalant allergens. The prevalence of atopic eczema, allergic rhinitis and asthma was significantly increased in our EE cohort compared with the general Australian population. A total of 24% of our cohort of patients with EE had a history of anaphylaxis. Conclusion: In children with EE, the sensitization to inhalant allergens increases with age, particularly after 4 years. Also, specific enquiry about severe food reactions in patients presenting with EE is strongly recommended as it appears this patient group has a high incidence of anaphylaxis. © 2007 The Authors.

Postprocedural effects of gastrointestinal endoscopy performed as a day case procedure in children : implications for patient and family education

A prospective design that included a survey tool, nursing care records, and telephone interview was used to determine postprocedural effects experienced by children and families following gastrointestinal endoscopy performed as a day procedure. One hundred twenty-one children attending a pediatric gastroenterology unit for endoscopy under general anesthesia participated in the study. Physical symptoms, day care/school attendance, behavioral issues, and economic factors in the 72 hours post procedure were identified. Over half the children (n = 69, 57%) experienced pain in the hospital post procedure. Pain was reported by 73 children (60%) at home on the day of the procedure, by 55 children (45%) on Day 1 post procedure, and by 37 children (31%) on Day 2 post procedure. The throat was the most common site of pain. Nausea or vomiting was experienced by 37 children (31%) at some time following their procedure but was not associated with procedure type, age, or fasting time. Over half the children (n = 53, 51%) who usually attended day care or school did not attend the day following their procedure. Twenty-four parents (40%) who would normally have worked on the day after the procedure did not attend employment. These findings have been used to improve the preprocedural information and discharge management of patients treated in a pediatric gastroenterology ambulatory setting. © The Society of Gastroenterology Nurses & Associates 2007. All Rights Reserved.

Genome-wide meta-analysis identifies 56 bone mineral density loci and reveals 14 loci associated with risk of fracture

Bone mineral density (BMD) is the most widely used predictor of fracture risk. We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 17 genome-wide association studies and 32,961 individuals of European and east Asian ancestry. We tested the top BMD-associated markers for replication in 50,933 independent subjects and for association with risk of low-trauma fracture in 31,016 individuals with a history of fracture (cases) and 102,444 controls. We identified 56 loci (32 new) associated with BMD at genome-wide significance (P < 5 × 10−8). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal stem cell differentiation, endochondral ossification and Wnt signaling pathways. However, we also discovered loci that were localized to genes not known to have a role in bone biology. Fourteen BMD-associated loci were also associated with fracture risk (P < 5 × 10−4, Bonferroni corrected), of which six reached P < 5 × 10−8, including at 18p11.21 (FAM210A), 7q21.3 (SLC25A13), 11q13.2 (LRP5), 4q22.1 (MEPE), 2p16.2 (SPTBN1) and 10q21.1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility.

Resting energy expenditure in children with inflammatory bowel disease

OBJECTIVES: There is controversy in the literature regarding the effect of inflammatory bowel disease (IBD) on resting energy expenditure (REE). In many cases this may have resulted from inappropriate adjustment of REE measurements to account for differences in body composition. This article considers how to appropriately adjust measurements of REE for differences in body composition between individuals with IBD. PATIENTS AND METHODS: Body composition, assessed via total body potassium to yield a measure of body cell mass (BCM), and REE measurements were performed in 41 children with Crohn disease and ulcerative colitis in the Royal Children's Hospital, Brisbane, Australia. Log-log regression was used to determine the power function to which BCM should be raised to appropriately adjust REE to account for differences in body composition between children. RESULTS: The appropriate value to "adjust" BCM was found to be 0.49, with a standard error of 0.10. CONCLUSIONS: Clearly, there is a need to adjust for differences in body composition, or at the very least body weight, in metabolic studies in children with IBD. We suggest that raising BCM to the power of 0.5 is both a numerically convenient and a statistically valid way of achieving this aim. Under circumstances in which the measurement of BCM is not available, raising body weight to the power of 0.5 remains appropriate. The important issue of whether REE is changed in cases of IBD can then be appropriately addressed. © 2007 Lippincott Williams & Wilkins, Inc.

'Free' surfactant in gastric aspirates and bronchoalveolar lavage in children with and without reflux oesophagitis

Aim: Dipalmitoylphosphatidycholine (DPPC) is the characteristic and main constituent of surfactant. Adsorption of surfactant to epithelial surfaces may be important in the masking of receptors. The aims of the study were to (i) compare the quantity of free DPPC in the airways and gastric aspirates of children with gastroesophageal reflux disease (GORD) to those without and (ii) describe the association between free DPPC levels with airway cellular profile and capsaicin cough sensitivity. Methods: Children aged <14 years were defined as 'coughers' if a history of cough in association with their GORD symptoms was elicited before gastric aspirates and nonbronchoscopic bronchoalveolar lavage (BAL) were obtained during elective flexible upper gastrointestinal endoscopy. GORD was defined as histological presence of reflux oesophagitis. Spirometry and capsaicin cough-sensitivity test was carried out in children aged >6 years before the endoscopy. Results: Median age of the 68 children was 9 years (interquartile range (IQR) 7.2). Median DPPC level in BAL of children with cough (72.7 μg/mL) was similar to noncoughers (88.5). There was also no significant difference in DPPC levels in both BAL and gastric aspirates of children classified according to presence of GORD. There was no correlation between DPPC levels and cellular counts or capsaicin cough-sensitivity outcome measures. Conclusion: We conclude that free DPPC levels in the airways and gastric aspirate is not influenced by presence of cough or GORD defined by histological presence of reflux oesophagitis. Whether quantification of adsorbed surfactant differs in these groups remain unknown. Free DPPC is unlikely to have a role in masking of airway receptors. © 2006 Royal Australasian College of Physicians.

Impact of ethnicity upon body composition assessment in Sri Lankan Australian children

Objectives: Obesity is a disease with excess body fat where health is adversely affected. Therefore it is prudent to make the diagnosis of obesity based on the measure of percentage body fat. Body composition of a group of Australian children of Sri Lankan origin were studied to evaluate the applicability of some bedside techniques in the measurement of percentage body fat. Methods: Height (H) and weight (W) was measured and BMI (W/H2) calculated. Bioelectrical impedance analysis (BIA) was measured using tetra polar technique with an 800 μA current of 50 Hz frequency. Total body water was used as a reference method and was determined by deuterium dilution and fat free mass and hence fat mass (FM) derived using age and gender specific constants. Percentage FM was estimated using four predictive equations, which used BIA and anthropometric measurements. Results: Twenty-seven boys and 15 girls were studied with mean ages being 9.1 years and 9.6 years, respectively. Girls had a significantly higher FM compared to boys. The mean percentage FM of boys (22.9 ± 8.7%) was higher than the limit for obesity and for girls (29.0 ± 6.0%) it was just below the cut-off. BMI was comparatively low. All but BIA equation in boys under estimated the percentage FM. The impedance index and weight showed a strong association with total body water (r 2 = 0.96, P < 0.001). Except for BIA in boys all other techniques under diagnosed obesity. Conclusions: Sri Lankan Australian children appear to have a high percentage of fat with a low BMI and some of the available indirect techniques are not helpful in the assessment of body composition. Therefore ethnic and/or population specific predictive equations have to be developed for the assessment of body composition, especially in a multicultural society using indirect methods such as BIA or anthropometry.

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background: Gastroesophageal reflux disease (GORD) can cause respiratory disease in children from recurrent aspiration of gastric contents. GORD can be defined in several ways and one of the most common method is presence of reflux oesophagitis. In children with GORD and respiratory disease, airway neutrophilia has been described. However, there are no prospective studies that have examined airway cellularity in children with GORD but without respiratory disease. The aims of the study were to compare (1) BAL cellularity and lipid laden macrophage index (LLMI) and, (2) microbiology of BAL and gastric juices of children with GORD (G+) to those without (G-). Methods: In 150 children aged <14-years, gastric aspirates and bronchoscopic airway lavage (BAL) were obtained during elective flexible upper endoscopy. GORD was defined as presence of reflux oesophagitis on distal oesophageal biopsies. Results: BAL neutrophil% in G- group (n = 63) was marginally but significantly higher than that in the G+ group (n = 77), (median of 7.5 and 5 respectively, p = 0.002). Lipid laden macrophage index (LLMI), BAL percentages of lymphocyte, eosinophil and macrophage were similar between groups. Viral studies were negative in all, bacterial cultures positive in 20.7% of BALs and in 5.3% of gastric aspirates. BAL cultures did not reflect gastric aspirate cultures in all but one child. Conclusion: In children without respiratory disease, GORD defined by presence of reflux oesophagitis, is not associated with BAL cellular profile or LLMI abnormality. Abnormal microbiology of the airways, when present, is not related to reflux oesophagitis and does not reflect that of gastric juices. © 2005 Chang et al; licensee BioMed Central Ltd.