Body-composition alterations consistent with cachexia in children and young adults with Crohn disease

Pathogenesis of Musculoskeletal Deficits in Children and Adults with Inflammatory Bowel Disease

Musculoskeletal deficits are among the most commonly reported extra-intestinal manifestations and complications of inflammatory bowel disease (IBD), especially in those with Crohn’s disease. The adverse effects of IBD on bone and muscle are multifactorial, including the direct effects of underlying inflammatory disease processes, nutritional deficits, and therapeutic effects. These factors also indirectly impact bone and muscle by interfering with regulatory pathways. Resultantly, individuals with IBD are at increased risk of osteoporosis and sarcopenia and associated musculoskeletal morbidity. In paediatric IBD, these factors may contribute to suboptimal bone and muscle accrual. This review evaluates the main pathogenic factors associated with musculoskeletal deficits in children and adults with IBD and summarises the current literature and understanding of the musculoskeletal phenotype in these patients.

Nutritional status and food intake in pediatric patients with inflammatory bowel disease at diagnosis significantly differs from healthy controls

Nutritional status and dietary intake in pediatric-onset inflammatory bowel disease are complex and need to be further explored. Therefore, we have assessed anthropometric measures, body composition, and dietary intake of newly diagnosed pediatric patients, and compared them with healthy controls. This was a prospective cross-sectional study including newly diagnosed patients with inflammatory bowel disease (n = 89) and healthy controls (n = 159). Mean energy intake was significantly lower in healthy controls compared to patients with ulcerative colitis, but not in patients with Crohn's disease. Intake of all macronutrients, dietary fiber, and calcium was significantly lower in patients with ulcerative colitis, whereas the only intake of animal protein, fruit, and calcium differed significantly in patients with Crohn's disease. There were no significant differences in the body fat percentage between patients with ulcerative colitis or Crohn's disease vs. controls; however, lean mass-for-age z-scores were significantly lower in patients with both diseases in comparison to controls.Conclusion: Food intake of newly diagnosed pediatric patients with inflammatory bowel disease significantly differed from healthy controls. Altered anthropometry and body composition are present already at the time of diagnosis. What is Known: • Children with inflammatory bowel disease suffer from malnutrition, especially children with Crohn's disease in whom linear growth failure often precedes gastrointestinal symptoms. What is New: • This study showed significantly lower intake of energy, macronutrients, and various micronutrients in patients with ulcerative colitis compared to healthy controls, while patients with Crohn's disease have a lower intake of fruits, calcium, and animal protein at diagnosis. • Altered body composition is present in both groups of patients at the time of diagnosis.

Minimally Invasive Surgery in Complex Crohn's Disease

Minimally invasive approaches are safe, feasible, and often recommended as the initial choice in the surgical management of Crohn's disease. However, a consensus has not been reached as the ideal approach in the surgical treatment of complex and recurrent Crohn's disease. Laparoscopy may provide advantages such as shorter length of stay and decreased postoperative pain and result in less adhesion formation in patients with complex disease. Robotic techniques may be beneficial in selected patients for completion proctectomy, providing better visualization in the narrow pelvis and increased dexterity. Decision of surgical technique should be made on a case-by-case basis.

A Vegetable and Fish Dietary Pattern Is Positively Associated with Skeletal Muscle Mass in Korean Men

Isolating the effects of a single nutrient or food in relation to health outcomes including increased skeletal muscle mass is a challenging task because dietary constituents are highly correlated and synergistic. Hence, diet pattern analysis may be used to investigate the role of certain diets in health outcomes. The present study investigated the dietary patterns and their relationship to skeletal muscle mass in Korean adults. Data were extracted from the 2008–2011 Korea National Health and Nutrition Examination Surveys. To explore the dietary patterns of the study subjects, factor analysis was performed using data obtained from a 24-hour recall. The skeletal muscle index according to dietary pattern scores was then investigated to estimate the changes in skeletal muscle mass. Three patterns were initially identified from the factor analysis. Of these vegetables and fish (VF) pattern was the primary factor with high reliability and was a common factor in sex-separated analyses. The VF pattern scores were positively associated with increased skeletal muscle mass in both men and women. Further analysis according to quartile levels of VF pattern scores showed a positive association between skeletal muscle mass and VF pattern in men but not in women. These results suggest that dietary patterns focused on vegetables and seafoods may contribute to increased skeletal muscle mass in Korean men but that sex difference should be considered in nutrition care for skeletal muscle health.

Bioelectrical Impedance Phase Angle as an Indicator of Malnutrition in Hospitalized Children with Diagnosed Inflammatory Bowel Diseases-A Case Control Study

The phase angle (PhA) seems to be a reliable screening tool for the identification of malnutrition risk in hospitalized children with inflammatory bowel disease (IBD). The aim of the present study was to assess the body composition and nutritional status of hospitalized children and adolescents with IBD by using bioelectrical impedance analysis (BIA) with phase angle (PhA) calculation, which has not been evaluated in hospitalized children with IBD yet. A total of 59 children and adolescents aged 4–18 years, with IBD: 34 ulcerative colitis (UC) and 25 Crohn’s disease (CD) were included in the study. The control group consisted of healthy children and adolescents, strictly matched for gender and age in a 1:1 case-control manner. In both groups, BIA was performed and PhA was calculated. IBD patients had significantly lower PhA (UC: 5.34 ± 1.34 vs. 5.96 ± 0.76, p = 0.040; CD: 5.16 ± 1.18 vs. 5.90 ± 0.62, p = 0.009) compared to the control subjects. Significant changes in selected body composition parameters were observed particularly in CD, especially in fat free mass components. Lower phase angle score together with lower body composition parameters and selected nutrition indicators in children and adolescents with IBD demonstrate their worse nutritional and functional status compared to healthy subjects.

Musculoskeletal system in children and adolescents with inflammatory bowel disease: normal muscle force, decreased trabecular bone mineral density and low prevalence of vertebral fractures

Low bone mineral density (BMD) and an increased fracture incidence are two extraintestinal complications associated with inflammatory bowel disease (IBD). We aimed to evaluate musculoskeletal traits and assess vertebral fracture (VF) rate in children and adolescents with IBD. Seventy patients with IBD with a median age of 13.8 years were included. The BMD and geometric parameters of the non-dominant tibia were assessed using pQCT. Dynamic muscle functions were evaluated using jumping mechanography. VFs were assessed according to the semiquantitative standardized method by Genant. The muscle functions adjusted for the patients' weight did not differ from the reference population. A low trabecular BMD (Z-score - 1.6; p < 0.001) and cortical thickness (Z-score - 0.7; p < 0.001) were found in children and adolescents with IBD. Conversely, an increased cortical BMD (Z-score 1.1; p < 0.001) was noted. No significant association was found between the 25-OHD serum levels and the bone or muscle measurements. One patient with asymptomatic VF was identified.

CONCLUSION

IBD in childhood or adolescents affects bones but not muscles. Bone changes are independent of the 25-OHD serum level. A thoracolumbar spine X-ray should not be routinely recommended in children with IBD. What is Known: • Low bone mineral density and an increased fracture rate are the complications associated with IBD. • Bone strength and structural development is strongly dependent on skeletal muscle stimulation. What is New: • Children with IBD have altered bone density and geometry but normal dynamic muscle functions. • Thoracolumbar spine X-ray should be indicated on an individual basis in children with IBD.

Body Composition in Crohn's Disease and Ulcerative Colitis: Correlation with Disease Severity and Duration

BACKGROUND

Results on body composition in Crohn's disease (CD) and ulcerative colitis (UC) have been heterogeneous and are lacking from Asia. Present study assessed body composition in CD/UC and correlated it with disease severity/duration.

METHODS

Patients of CD/UC following between Dec 2014 and Dec 2015 who consented for bioimpedance analysis for body fat measurement were included. Lean mass and fat-free mass index (FFMI) were calculated with standard formulae. Visceral fat area (VFA), subcutaneous fat area (SCA), and visceral to subcutaneous fat ratio (VF/SC) were evaluated in CD patients on abdominal CT.

RESULTS

Lean mass in CD (n = 44, mean age: 41.2 ± 15.8 years, 73% males) was significantly lower than UC (n = 53, mean age: 33.2 ± 11.2 years, 68% males; 44.2 ± 7.8 versus 48.3 ± 8.4 Kg, p = 0.01). In both UC/CD, disease severity was associated with nonsignificant decline in BMI (UC: 22.1 ± 4.9 versus 20.2 ± 3.2 versus 19.9 ± 3.2 kg/m², p = 0.23; CD: 22.1 ± 4.2 versus 19.9 ± 2.3 versus 19.7 ± 4.2 kg/m², p = 0.18) and fat mass (UC: 10.9 ± 8.9 versus 8.1 ± 5.9 versus 5.7 ± 3.6 kg, p = 0.14; CD: 11.2 ± 7 versus 7.9 ± 4.4 versus 7.2 ± 5.9 kg, p = 0.16), and disease duration was associated with significant decline in FFMI (p < 0.05). In CD, disease severity was associated with nonsignificant decline in SCA and increase in VF/SC.

CONCLUSIONS

CD patients have lower lean mass than UC. Body fat decreases with increasing disease severity and fat-free mass decreases with increasing disease duration in both UC/CD.

Obesity and Pediatric Psoriatic Arthritis

Objective

Studies in adults have shown a significant association between obesity and psoriatic arthritis, however the association of obesity with pediatric psoriatic arthritis is unknown. We aimed to evaluate obesity in pediatric psoriatic arthritis.

Methods

We conducted a cross-sectional study of children with psoriasis and psoriatic arthritis evaluated at a single center between 6/2010 and 9/2014. Two healthy reference populations were utilized: 1) local reference population from the surrounding community and 2) a national reference population derived from NHANES. Age and sex-specific z-scores for weight, height, and body mass index (BMI) were calculated. Differences in clinical and demographic characteristics between groups were assessed.

Results

During the study period, 48 children with psoriatic arthritis and 231 patients with psoriasis were evaluated. Three (6.2%) and 5 (10.4%) of the children with psoriatic arthritis were overweight or obese, respectively. In comparison to the reference healthy groups and psoriasis patients, the mean BMI z-score of children with psoriatic arthritis was not statistically different. However, patients with psoriasis were more likely to be obese than the community reference population (p-value <0.001).

Conclusions

Children with psoriasis were more obese than the healthy reference population, however there was no statistically significant difference in obesity between children with psoriatic arthritis and psoriasis or psoriatic arthritis and the reference population. This lack of association may be reflective of true differences in pediatric and adult-onset disease and warrants further investigation.

Body composition as an indicator of the nutritional status in children with newly diagnosed ulcerative colitis and Crohn's disease - a prospective study

Introduction

The prevalence of nutritional status disorders in children with ulcerative colitis (UC) is much lower than in the case of Crohn’s disease (CD). The largest variability in the components of body composition occurs at the time of a new diagnosis and in periods of disease exacerbation.

Aim

Assessment of body composition in children with UC and CD.

Material and methods

The preliminary study included 59 children with inflammatory bowel disease (IBD) (34 children with UC vs. 25 children with CD) aged 4–18 years. The final analysis included 26 newly diagnosed children (16 children with UC vs. 10 children with CD). The evaluation of body composition was conducted by means of BIA-101 bioimpedance analyser.

Results

Decreased values of lean mass were found in children with newly diagnosed IBD (UC: 41.13 kg vs. control group: 42.06 kg; CD: 35.50 kg vs. control group: 45.50 kg). After a year interval, an increase in fat (UC 1: 7.67 kg vs. UC 2: 10.33 kg; CD 1: 7.36 kg vs. CD 2: 9.47 kg) as well as lean body mass (UC 1: 35.22 kg vs. UC 2: 39.00 kg; CD 1: 35.99 kg vs. CD 2: 42.41 kg) was found in children.

Conclusions

Children with newly diagnosed IBD were highly vulnerable to nutritional status disturbances. The increase in fat and lean body mass in an annual interval may be due to the treatment regime and control of the children.

Peripheral quantitative computed tomography (pQCT) for the assessment of bone strength in most of bone affecting conditions in developmental age: a review

Peripheral quantitative computed tomography provides an automatical scan analysis of trabecular and cortical bone compartments, calculating not only their bone mineral density (BMD), but also bone geometrical parameters, such as marrow and cortical Cross-Sectional Area (CSA), Cortical Thickness (CoTh), both periosteal and endosteal circumference, as well as biomechanical parameters like Cross-Sectional Moment of Inertia (CSMI), a measure of bending, polar moment of inertia, indicating bone strength in torsion, and Strength Strain Index (SSI). Also CSA of muscle and fat can be extracted. Muscles, which are thought to stimulate bones to adapt their geometry and mineral content, are determinant to preserve or increase bone strength; thus, pQCT provides an evaluation of the functional 'muscle-bone unit', defined as BMC/muscle CSA ratio. This functional approach to bone densitometry can establish if bone strength is normally adapted to the muscle force, and if muscle force is adequate for body size, providing more detailed insights to targeted strategies for the prevention and treatment of bone fragility. The present paper offers an extensive review of technical features of pQCT and its possible clinical application in the diagnostic of bone status as well as in the monitoring of the skeleton's health follow-up.

Nutritional perspectives of children with Crohn's disease: a single-centre cohort observation of disease activity, energy expenditure and dietary intake

BACKGROUND/OBJECTIVES

Children with Crohn's disease often demonstrate nutritional recovery during primary therapy at diagnosis, but long-term nutritional support is sometimes necessary. Evidence to inform best nutritional practice including energy and micronutrient requirements is limited. The principal objective of this study was to determine how energy expenditure and physical activity vary with disease activity over the first year following diagnosis.

SUBJECTS/METHODS

Twenty children were studied at diagnosis with Crohn's disease and were followed up over 1 year while receiving treatment according to national guidelines. The majority of children (13) were treated with exclusive enteral nutrition. At study visits, height, weight, bioelectrical impedance, resting energy expenditure by indirect calorimetry, tri-axial accelerometer and blood investigations were performed alongside clinical assessment.

RESULTS

There was no significant effect of disease activity on resting energy expenditure (REE). Physical activity was greater after primary therapy (Z=3.31, P<0.01). Median wPCDAI fell from 58 at diagnosis to 7.5 after primary therapy and was 7.5 at 1 year. Weight s.d.s increased from -1.67 to -0.86 and lean index s.d.s increased from -2.93 to -1.64, although the increase was mostly in the first 2 months. Median height s.d.s was unchanged throughout this study. There was a significant association between dietary intake and weight gain (r=0.8 P<0.01) but not height gain. Persistent micronutrient deficits beyond diagnosis were seen for both iron and vitamin D.

CONCLUSIONS

This study has demonstrated that REE does not change significantly through different phases of disease activity, but physical activity is low at diagnosis. Children with Crohn's disease should be screened for deficiencies of iron and vitamin D.

Body Mass Index Is Associated with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Background

Prior work suggested that patients with inflammatory bowel diseases (IBD) have lower body mass index (BMI) than controls and patients with lower BMI have more serious complications.

Goal

The study was aimed to find relationship between BMI in patients with and without IBD, investigate effects of medicine therapy and disease stages on patients’ BMI.

Methods

Potentially eligible studies were identified through searching PubMed, Cochrane and Embase databases. Outcome measurements of mean BMI and the number of patients from each study were pooled by a random-effect model. Publication bias test, sensitivity analysis and subgroup analysis were conducted.

Results

A total of 24 studies containing 1442 patients and 2059 controls were included. Main results were as follows: (1) BMI in Crohn’s disease (CD) patients was lower than that in health controls (-1.88, 95% CI -2.77 to -1.00, P< 0.001); (2) Medical therapy significantly improved BMI of CD patients (with therapy: -1.58, -3.33 to 0.16; without: -2.09, 95% CI -3.21 to -0.98) while on the contrary not significantly improving BMI of UC patients (with therapy: -0.24, 95% CI -3.68 to 3.20; without: -1.34, 95% CI -2.87 to 0.20, P = 0.57); (3) Both CD and UC patients in active phase showed significantly greater BMI difference compared with controls than those in remission (CD patients: remission: -2.25, 95% CI -3.38 to -1.11; active phase: -4.25, 95% CI -5.58 to -2.92, P = 0.03; UC patients: remission: 0.4, 95% CI -2.05 to 2.84; active phase: -5.38, -6.78 to -3.97, P = 0.001).

Conclusions

BMI is lower in CD patients; medical therapy couldn’t improve BMI of IBD patients; the state of disease affects BMI of CD patients and UC patients.

Cachexia & debility diagnoses in hospitalized children and adolescents with complex chronic conditions: evidence from the Kids' Inpatient Database

Objective:

To characterize the frequency, cost, and hospital-reported outcomes of cachexia and debility in children and adolescents with complex chronic conditions (CCCs).

Methods:

We identified children and adolescents (aged ≤20 years) with CCCs, cachexia, and debility in the Kids’ Inpatient Database [Healthcare Cost and Utilization Project, Agency for Healthcare Research & Quality]. We then compared the characteristics of patients and hospitalizations, including cost and duration of stay, for CCCs with and without cachexia and/or debility. We examined factors that predict risk of inpatient mortality in children and adolescents with CCCs using a logistic regression model. We examined factors that impact duration of stay and cost in children and adolescents with CCCs using negative binomial regression models. All costs are reported in US dollars in 2014 using Consumer Price Index inflation adjustment.

Results:

We estimated the incidence of hospitalization of cachexia in children and adolescents with CCCs at 1,395 discharges during the sample period, which ranged from 277 discharges in 2003 to 473 discharges in 2012. We estimated the incidence of hospitalization due to debility in children and adolescents with CCCs at 421 discharges during the sample period, which ranged from 39 discharges in 2003 to 217 discharges in 2012. Cachexia was associated with a 60% increase in the risk of inpatient mortality, whereas debility was associated with a 40% decrease in the risk of mortality. Cachexia and debility increased duration of stay in hospital (17% and 39% longer stays, respectively). Median cost of hospitalization was $15,441.59 and $23,796.16 for children and adolescents with cachexia and debility, respectively.

Conclusions:

Incidence of hospitalization for cachexia in children and adolescents with CCCs is less than that for adults but the frequency of cachexia diagnoses increased over time. Estimates of the incidence of hospitalization with debility in children and adolescents with CCCs have not been reported, but our study demonstrates that the frequency of these discharges is also increasing.

Deficits in muscle mass, muscle density, and modified associations with fat in rheumatoid arthritis

OBJECTIVE

To quantify muscle outcomes, independent of fat mass, in rheumatoid arthritis (RA) patients compared to healthy controls.

METHODS

Quantitative computed tomography scans measured calf muscle and fat cross-sectional area (CSA) and muscle density (an index of intramuscular adipose tissue), and isometric dynamometry was used to measure ankle muscle strength in 50 participants with RA ages 18-70 years and 500 healthy controls. Multivariable linear regression models assessed muscle deficits in RA after adjusting for group differences in adiposity and assessing for an altered muscle-fat association. Associations between RA disease characteristics and fat-adjusted muscle outcomes were also assessed.

RESULTS

Compared to controls, RA subjects had significantly greater body mass index (BMI) and fat area, and lower muscle area, muscle density, and muscle strength (P < 0.001 for all). Strength deficits were eliminated with adjustment for the smaller muscle area. The magnitude of muscle deficits, relative to controls, was significantly greater (P < 0.03 for interaction) in participants with lower fat area and BMI. Among those in the lower tertiles of adiposity, RA subjects demonstrated more significant deficits compared to controls with similar adiposity. In contrast, among those in the highest tertile for adiposity, RA was not associated with muscle deficits. Among RA, greater Sharp/van der Heijde scores were associated with lower muscle CSA and muscle density. Greater disease activity and disability were associated with low muscle density.

CONCLUSION

Deficits in muscle area and muscle density are present in RA patients compared to controls and are most pronounced in subjects with low fat mass. Greater joint destruction is associated with greater muscle deficits.

Changes in trabecular bone density in incident pediatric Crohn's disease: a comparison of imaging methods

This study of changes in dual energy x-ray absorptiometry (DXA) spine BMD following diagnosis and treatment for childhood Crohn's disease demonstrated that changes in conventional posteroanterior BMD results were confounded by impaired growth, and suggested that lateral spine measurements and strategies to estimate volumetric BMD were more sensitive to disease and treatment effects.

INTRODUCTION

We previously reported significant increases in peripheral quantitative CT (pQCT) measures of trabecular volumetric bone mineral density (vBMD) following diagnosis and treatment of pediatric Crohn's disease (CD). The objective of this study was to compare pQCT trabecular vBMD and three DXA measures of spine BMD in this cohort: (1) conventional posteroanterior BMD (PA-BMD), (2) PA-BMD adjusted for height Z (PA-BMDHtZ), and (3) width-adjusted volumetric BMD (WA-BMD) estimated from PA and lateral scans.

METHODS

Spine DXA [lumbar (L1-4) for posteroanterior and L3 for lateral] and tibia pQCT scans were obtained in 65 CD subjects (ages 7-18 years) at diagnosis and 12 months later. BMD results were converted to sex, race, and age-specific Z-scores based on reference data in >650 children (ages 5-21 years). Multivariable linear regression models identified factors associated with BMD Z-scores.

RESULTS

At CD diagnosis, all BMD Z-scores were lower compared with the reference children (all p values <0.01). The pQCT vBMD Z-scores (-1.46 ± 1.30) were lower compared with DXA PA-BMD (-0.75 ± 0.98), PA-BMDHtZ (-0.53 ± 0.87), and WA-BMD (-0.61 ± 1.10) among CD participants. Only PA-BMD Z-scores were correlated with height Z-scores at baseline (R = 0.47, p < 0.0001). pQCT and WA-BMD Z-scores increased significantly over 12 months to -1.04 ± 1.26 and -0.20 ± 1.14, respectively. Changes in all four BMD Z-scores were positively associated with changes in height Z-scores (p < 0.05). Glucocorticoid doses were inversely associated with changes in WA-BMD (p < 0.01) only.

CONCLUSIONS

Conventional and height Z-score-adjusted PA DXA methods did not demonstrate the significant increases in trabecular vBMD noted on pQCT and WA-BMD scans. WA-BMD captured glucocorticoid effects, potentially due to isolation of the vertebral body on the lateral projection. Future studies are needed to identify the BMD measure that provides greatest fracture discrimination in CD.

Exclusive enteral nutrition induces early clinical, mucosal and transmural remission in paediatric Crohn's disease

BACKGROUND AND AIMS

Exclusive enteral nutrition (EEN) induces clinical and mucosal healing (MH) in Crohn's disease (CD), with MH the best determinant of future outcome. We investigated efficacy of EEN for inducing early clinical, biochemical, mucosal and transmural remission of CD and related early endoscopic response to outcomes at 1 year.

METHODS

In a prospective, open label study 34 children (mean 13.1 years; 21 males) with new diagnosis CD were offered EEN, 26 completed a minimum 6 weeks EEN and underwent paired clinical, biochemical and endoscopic assessment at start and completion using PCDAI, BMI, CRP and Simple Endoscopic Score for CD (SES-CD). A subset, 16/26, had paired MR enterography scored. Early good endoscopic response (complete MH, or near complete, SES-CD 0-3) was related to outcome at 1 year.

RESULTS

EEN improved mean PCDAI (37.88-7.01, p < 0.001; BMI Z scores (-1.54 to -0.54, p < 0.01); weight Z score (-0.79 to -0.08, p < 0.03); CRP (44.86-5.5, p < 0.001); endoscopy (SES-CD 14.28-3.88, p < 0.001) and MRE (5.14-2.79, p = 0.01). Of 26 children, 22 (84 %) achieved clinical remission; 20 (76 %) biochemical remission. Fifteen (58 %) had early good endoscopic response (11 complete, 4 near complete MH) and 3/14 (21 %) had complete transmural remission of ileal CD (MRE-CD: 0-1). Early good endoscopic response was associated with reduced endoscopic confirmed relapse (53 vs. 100 %, p = 0.02), anti-TNF use (33 vs. 88 %, p = 0.01) and hospitalisation (40 vs. 88 %) at 1 year.

CONCLUSIONS

EEN is effective for inducing early clinical, biochemical, mucosal and transmural remission. Early endoscopic remission improves outcomes at 1 year.

Application of body mass index according to height-age in short and tall children

Background

In children with either delayed or accelerated growth, expressing the body mass index (BMI) to chronological age might lead to invalid body composition estimates. Reference to height-age has been suggested for such populations; however its validity has not been demonstrated.

Methods

Anthropometric data of healthy children were obtained from the German KiGGS survey. We selected three samples with different height distributions representing short stature (mean height SDS: -1.6), normal stature (height SDS: 0), and tall stature (height SDS: +1.6), and compared BMI-for-age and BMI-for-height-age between these samples across the paediatric age range. Differences between samples were tested using Kruskal-Wallis one-way analysis of variance and permutation tests.

Results

At a given age, BMI was distributed towards lower values in short, and towards higher values in tall subjects as compared to a population with average height distribution. Expressing BMI to height-age eliminated these differences in boys with a short stature from 4 years to 14 years of age, in tall boys from 4 to 16 years, in short girls aged 2-10 years or tall girls aged 2-17 years.

Conclusion

From late infancy to adolescent age, BMI distribution co-varies with height distribution and referencing to height-age appears appropriate within this age period. However, caution is needed when data about pubertal status are absent.

Body composition abnormalities in long-term survivors of pediatric hematopoietic stem cell transplantation

OBJECTIVE

To quantify lean mass (LM) and fat mass (FM) in survivors of childhood allogeneic hematopoietic stem-cell transplantation (alloHSCT) compared with healthy reference participants and identify risk factors for body composition abnormalities.

STUDY DESIGN

Whole body LM and FM were measured with dual energy x-ray absorptiometry in 54 survivors (ages 5-25 years) and 894 healthy reference participants in a cross-sectional study. Multivariate regression models were used to compare sex- and race-specific Z-scores for LM for height (LM-Ht) and FM for height (FM-Ht) in survivors and reference participants and to identify correlates of LM-Ht and FM-Ht Z-scores in alloHSCT.

RESULTS

Height Z-scores were significantly lower in alloHSCT survivors (P < .001) compared with reference participants; body mass index Z-scores did not differ (P = .13). Survivors had significantly lower mean LM-Ht Z-scores (-0.72; 95% CI, -1.02--0.42; P < .001) and greater FM-Ht Z-scores (1.10; 95% CI, 0.84-1.39; P < .001) compared with reference participants. LM-Ht Z-score deficits in alloHSCT survivors were larger (-1.26; 95% CI, -1.53--0.99; P < .001) after adjustment for FM-Ht Z-scores. Endocrinopathies and alloHSCT characteristics were not associated with LM-Ht or FM-Ht Z-scores.

CONCLUSION

Survivors of childhood alloHSCT have significant LM deficits and FM excess. Future studies should identify the mechanism and consequences of these abnormalities.

Association of chronic kidney disease with muscle deficits in children

The effect of chronic kidney disease (CKD) on muscle mass in children, independent of poor growth and delayed maturation, is not well understood. We sought to characterize whole body and regional lean mass (LM) and fat mass (FM) in children and adolescents with CKD and to identify correlates of LM deficits in CKD. We estimated LM and FM from dual energy x-ray absorptiometry scans in 143 children with CKD and 958 controls at two pediatric centers. We expressed whole body, trunk, and leg values of LM and FM as Z-scores relative to height, sitting height, and leg length, respectively, using the controls as the reference. We used multivariable regression models to compare Z-scores in CKD and controls, adjusted for age and maturation, and to identify correlates of LM Z-scores in CKD. Greater CKD severity associated with greater leg LM deficits. Compared with controls, leg LM Z-scores were similar in CKD stages 2 to 3 (difference: 0.02 [95% CI: -0.20, 0.24]; P = 0.8), but were lower in CKD stages 4 to 5 (-0.41 [-0.66, -0.15]; P = 0.002) and dialysis (-1.03 [-1.33, -0.74]; P < 0.0001). Among CKD participants, growth hormone therapy associated with greater leg LM Z-score (0.58 [0.03, 1.13]; P = 0.04), adjusted for CKD severity. Serum albumin, bicarbonate, and markers of inflammation did not associate with LM Z-scores. CKD associated with greater trunk LM and FM, variable whole body LM, and normal leg FM, compared with controls. In conclusion, advanced CKD associates with significant deficits in leg lean mass, indicating skeletal muscle wasting. These data call for prospective studies of interventions to improve muscle mass among children with CKD.

The impact of inflammation on bone mass in children

Bone is a dynamic tissue. Skeletal bone integrity is maintained through bone modeling and remodeling. The mechanisms underlying this bone mass regulation are complex and interrelated. An imbalance in the regulation of bone remodeling through bone resorption and bone formation results in bone loss. Chronic inflammation influences bone mass regulation. Inflammation-related bone disorders share many common mechanisms of bone loss. These mechanisms are ultimately mediated through the uncoupling of bone remodeling. Cachexia, physical inactivity, pro-inflammatory cytokines, as well as iatrogenic factors related to effects of immunosuppression are some of the common mechanisms. Recently, cytokine signaling through the central nervous system has been investigated for its potential role in bone mass dysregulation in inflammatory conditions. Growing research on the molecular mechanisms involved in inflammation-induced bone loss may lead to more selective therapeutic targeting of these pathological signaling pathways.

Nutritional status and nutritional therapy in inflammatory bowel diseases

Underweight and specific nutrient deficiencies are frequent in adult patients with inflammatory bowel disease (IBD). In addition, a significant number of children with IBD, especially Crohn’s disease (CD) have impaired linear growth. Nutrition has an important role in the management of IBD. In adults with CD, enteral nutrition (EN) is effective in inducing clinical remission of IBD, although it is less efficient than corticosteroids. Exclusive EN is an established primary therapy for pediatric CD. Limited data suggests that EN is as efficient as corticosteroids for induction of remission. Additional advantages of nutritional therapy are control of inflammation, mucosal healing, positive benefits to growth and overall nutritional status with minimal adverse effects. The available evidence suggests that supplementary EN may be effective also for maintenance of remission in CD. More studies are needed to confirm these findings. However, EN supplementation could be considered as an alternative or as an adjunct to maintenance drug therapy in CD. EN does not have a primary therapeutic role in ulcerative colitis. Specific compositions of enteral diets-elemental diets or diets containing specific components-were not shown to have any advantage over standard polymeric diets and their place in the treatment of CD or UC need further evaluation. Recent theories suggest that diet may be implicated in the etiology of IBD, however there are no proven dietary approaches to reduce the risk of developing IBD.

Hormonal regulators of appetite

Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger and satiety. Mutations in these hormones or their receptors can cause substantial pathology leading to obesity or anorexia. Identification of individuals with specific genetic mutations may ultimately lead to more appropriate therapies targeted at the underlying disease process. Thus far, these hormones have mainly been studied in adults and animal models. This article is aimed at reviewing the hormones involved in hunger and satiety, with a focus on pediatrics.