Body composition reference data for a young multiethnic female population

Systematic review: Sarcopenia in paediatric inflammatory bowel disease

BACKGROUND

Low skeletal muscle mass (MM) and deteriorated function (sarcopenia) can be a frequent complication in paediatric inflammatory bowel disease (IBD).

AIM

To conduct a systematic review of the paediatric IBD literature on skeletal muscle function and mass and identify interventions that could affect them.

METHODS

Systematic searches (EMBASE, Medline, Cochrane library central for registered control trials and Web of Science) were conducted using the terms 'lean body mass' (LM), 'fat free mass' (FFM) or 'MM' and 'IBD'.

RESULTS

Fourteenth studies were included, presenting data from 439 Crohn's disease (CD), 139 ulcerative colitis (UC) and 2 IBD-unclassified participants compared with healthy matched or unmatched groups or reference populations. Six out of 14 studies reported lower LM, whilst 7 studies observed lower MM and FFM in CD patients compared to healthy controls. Research in UC patients reported lower LM in 3 studies, lower MM in 3 studies and lower FFM in 4 studies. Three prospective studies measured the impact of enteral feeding and showed improvement on disease activity and LM or FFM, while one retrospective study did not show any impact on LM.

CONCLUSION

Despite the variety of experimental approaches and methods used to assess sarcopenia, most studies showed reduction in MM, LM and FFM in IBD. Nutritional intervention may have a positive effect on LM and FFM. Future research should focus on standardizing the terminology and methodologies used in assessing body composition and investigating sarcopenia in diseased and matched healthy control cohorts in adequately powered studies with a longitudinal design.

Body composition from birth to 2 years

Providing all infants with the best start to life is a universal but challenging goal for the global community. Historically, the size and shape of infants, quantified by anthropometry and commencing with birthweight, has been the common yardstick for physical growth and development. Anthropometry has long been considered a proxy for nutritional status during infancy when, under ideal circumstances, changes in size and shape are most rapid. Developed from data collected in the Multicentre Growth Reference Study (MGRS), WHO Child Growth Standards for healthy infants and children have been widely accepted and progressively adopted. In contrast, and somewhat surprisingly, much less is understood about the 'quality' of growth as reflected by body composition during infancy. Recent advances in body composition assessment, including the more widespread use of air displacement plethysmography (ADP) across the first months of life, have contributed to a progressive increase in our knowledge and understanding of growth and development. Along with stable isotope approaches, most commonly the deuterium dilution (DD) technique, the criterion measure of total body water (TBW), our ability to quantify lean and fat tissue using a two-compartment model, has been greatly enhanced. However, until now, global reference charts for the body composition of healthy infants have been lacking. This paper details some of the historical challenges associated with the assessment of body composition across the first two years of life, and references the logical next steps in growth assessments, including reference charts.

Body Composition Measurements from Birth through 5 Years: Challenges, Gaps, and Existing & Emerging Technologies-A National Institutes of Health workshop

Body composition estimates are widely used in clinical research and field studies as measures of energy-nutrient balance, functionality and health. Despite their broad relevance and multiple applications, important gaps remain in techniques available for accurately and precisely quantifying body composition in infants and children from birth through 5 years. Identifying these gaps and highlighting research needs in this age group were the topics of a National Institutes of Health workshop held in Bethesda, MD, USA, 30-31 May 2019. Experts reviewed available methods (multicompartment models, air-displacement plethysmography, dual-energy X-ray absorptiometry, weight-length and height indices, bioimpedance analysis, anthropometry-skinfold techniques, quantitative magnetic resonance, optical imaging, omics and D3-creatine dilution), their limitations in this age range and high priority research needs. A summary of their individual and collective workshop deliberations is provided in this report.

Systematic review: Body composition in children with inflammatory bowel disease

BACKGROUND

Paediatric inflammatory bowel disease (IBD) is associated with weight loss, growth restriction and malnutrition. Bone mass deficits are well described, little is known about other body composition compartments.

AIMS

To define the alterations in non-bone tissue compartments in children with IBD, and explore the effects of demographic and disease parameters.

METHODS

A systematic search was carried out in the PubMed (www.ncbi.nlm.nih.gov/pubmed) and Web of Science databases in May 2014 (limitations age <17 years, and composition measurements compared with a defined control population).

RESULTS

Twenty-one studies were included in this systematic review, reporting on a total of 1479 children with IBD [1123 Crohn's disease, 243 ulcerative colitis], pooled mean age 13.1 ± 3.2 years, and 34.9% female. Data were highly heterogeneous, in terms of methodology and patients. Deficits in protein-related compartments were reported. Lean mass deficits were documented in 93.6% of Crohn's disease and 47.7% of ulcerative colitis patients when compared with healthy control populations. Lower lean mass was common to both sexes in Crohn's disease and ulcerative colitis, deficits in females with persisted for longer. Fat-related compartment findings were inconsistent, some studies report reductions in body fat in new diagnosis/active Crohn's disease.

CONCLUSIONS

It is clear that almost all children with Crohn's disease and half with ulcerative colitis have reduced lean mass, however, body fat alterations are not well defined. To understand what impact this may have on health and disease in children with IBD, further studies are needed to identify in which tissues these deficits lie, and to quantify body fat and its distribution.

The correlation between calcaneus stiffness index calculated by QUS and total body BMD assessed by DXA in Chinese children and adolescents

Few studies have shown comparison data between calcaneus stiffness index (SI) calculated by quantitative ultrasound (QUS) and bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) in the Chinese population. This study was aimed to examine the correlations between calcaneus SI calculated by QUS and total body BMD and bone mineral content (BMC) measured by DXA in Chinese children and adolescents. We measured the total body BMD and BMC using Lunar Prodigy (GE Healthcare), and speed of sound (SOS), broadband ultrasound attenuation (BUA), and a calculated SI of the left os calcis using Lunar Achilles Express (GE Healthcare) in 392 healthy Chinese schoolchildren and adolescents aged 5-19 years. The short-term precision for DXA was 0.5 % for total body BMD. The precision for QUS was 1.8 % for SI, 2.9 % for BUA, and 0.4 % for SOS. Pearson's correlation coefficients (r) were calculated to assess the possible correlations between the total body BMC by DXA and SI calculated by QUS. There were significantly positive correlations between SI of the left os calcis and total body BMD (r = 0.693, p < 0.001, n = 392) and BMC (r = 0.690, p < 0.001, n = 392). For all the subjects, significant positive correlations were observed between the calcaneal SI and the age, weight, height, BMI, total body BMD, total body BMC, total body lean mass, and total body fat mass, with r ranging from 0.310 (total body fat mass) to 0.693 (total body BMD) (p < 0.001, n = 392). In conclusion, QUS bone densitometry is a useful measuring method showing the physiological bone development in childhood and adolescence.

Variable dietary management of methylmalonic acidemia: metabolic and energetic correlations

BACKGROUND

Isolated methylmalonic acidemia (MMA) is managed by dietary protein restriction and medical food supplementation. Resting energy expenditure (REE) can be depressed in affected individuals for undefined reasons.

OBJECTIVE

The objective was to document the spectrum of nutritional approaches used to treat patients with MMA, measure REE, and analyze the dependence of REE on body composition, biochemical, and nutritional variables.

DESIGN

Twenty-nine patients with isolated MMA (22 mut, 5 cblA, 2 cblB; 15 males, 14 females; age range: 2-35 y) underwent evaluation. REE was measured with open-circuit calorimetry and compared with predicted values by using age-appropriate equations.

RESULTS

Nutritional regimens were as follows: protein restriction with medical food (n = 17 of 29), protein restriction with medical food and supplemental isoleucine or valine (n = 5 of 29), or the use of natural protein alone for dietary needs (n = 7 of 29). Most mut patients had short stature and higher percentage fat mass compared with reference controls. Measured REE decreased to 74 ± 13.6% of predicted (P < 0.001) in the ≤ 18-y group (n = 22) and to 83 ± 11.1% (P = 0.004) in patients aged >18 y (n = 7). Linear regression modeling suggested that age (P = 0.001), creatinine clearance (P = 0.01), and height z score (P = 0.04) accounted for part of the variance of measured REE per kilogram of fat-free mass (model R² = 0.66, P < 0.0001).

CONCLUSIONS

There is wide variation in the dietary treatment of MMA. Standard predictive equations overestimate REE in this population primarily due to their altered body composition and decreased renal function. Defining actual energy needs will help optimize nutrition and protect individuals from overfeeding. This trial is registered at clinicaltrials.gov as NCT00078078.

Gender differences in body composition deficits at diagnosis in children and adolescents with Crohn's disease

BACKGROUND

Childhood Crohn's disease (CD) is associated with poor growth and decreased body mass index (BMI); however, lean mass (LM) and fat mass (FM) deficits prior to therapy have not been characterized.

OBJECTIVES

To quantify LM and FM in incident pediatric CD subjects and controls, and to identify determinants of LM and FM deficits.

METHODS

Whole body LM and FM were assessed using DXA in 78 CD subjects and 669 healthy controls, ages 5-21 yr. Gender specific z-scores for LM (LM-Ht) and FM (FM-Ht) relative to height were derived using log linear regression models in the controls. Multivariate linear regression models adjusted for potential confounders.

RESULTS

CD was associated with significantly lower height and BMI for age. Within CD subjects, FM-Ht and LM-Ht were significantly lower in females compared with males (FM-Ht z: -0.66+/-0.83 vs. -0.08+/-0.95, p<0.01; LM-Ht z: -1.12+/-1.12 vs. -0.57+/-0.99, p<0.05). In females, CD was associated with significantly lower LM-Ht (p<0.001) and FM-Ht (p=0.001), adjusted for age, race and Tanner stage, compared with controls. LM and FM deficits were significantly greater in older females with CD; 47% of adolescent females had LM-Ht<or=5th percentile. In non-black males, CD was also associated with lower LM-Ht (p<0.02); FM-Ht deficits were not significant.

CONCLUSIONS

Incident CD was associated with significant LM deficits in males and females, and FM deficits in females. Future studies are needed to identify etiologies for the age and gender differences and to evaluate therapies for these deficits.

Predictors of body fat gain in nonobese girls with a familial predisposition to obesity

BACKGROUND

Conflicting evidence exists on the causal factors underlying the development of excess adiposity in children.

OBJECTIVE

We determined the effect of energy expenditure (EE), muscle energetics, and physical fitness on weight and fat gain in prepubertal girls with or without a predisposition to obesity.

DESIGN

Normal-weight girls (n = 101) were recruited at 8 y of age according to parental body mass index. Eighty-eight girls completed the 2-y study, and the groups were as follows: LN, girls with 2 lean parents; LNOB, girls with 1 obese and 1 lean parent; and OB, girls with 2 obese parents. Measurements of weight, height, and body composition were taken 1 and 2 y after baseline. Girls underwent baseline measurements of EE by 24-h calorimetry and doubly labeled water, of muscle metabolism by (31)P nuclear magnetic resonance, and of fitness.

RESULTS

Fat mass (FM) and percentage body fat (%BF) differed significantly between the groups at years 1 and 2; the OB group had higher FM (P = 0.03) and %BF (P = 0.046) at year 1 and higher FM (P = 0.047) at year 2 than did the LN group. After adjustment for baseline weight, group, time, ethnicity, and Tanner stage, sleep EE, basal EE, 24-h EE, and peak oxygen uptake were negatively associated with FM and %BF (P < 0.04). After adjustment for the same variables, muscle oxidative capacity and free-living total EE were negatively and positively predictive, respectively, of changes in %BF between 8 and 10 y of age (both P = 0.04).

CONCLUSIONS

Nonobese girls with 2 obese parents have a significant risk of developing obesity. High free-living total EE and low muscle oxidative capacity predict high rates of fat gain.

Evaluation of body composition: practical guidelines

The measurement of body composition in the truest sense allows for the estimation of body tissues, organs, and their distributions in living persons without inflicting harm. It is important to recognize that there is no single measurement method that is error-free. Furthermore, bias can be introduced if a measurement method makes assumptions related to body composition proportions and characteristics that are inaccurate across different populations. Some methodologic concerns include hydration of fat-free body mass changes with age and differences across ethnic groups [73]; the density of fat-free body mass changes with age and differences between men and women [74, 75]; total body potassium decreases with age [73] and fatness [76] and differences between African Americans and Caucasians [77]; the mass of skeletal muscle differences across race group [63]; and VAT differences across sex [78] and race [67, 79, 80] groups, independent of total adiposity. These between-group differences influence the absolute accuracy of methods for estimating fatness or FFM that involve the two-compartment model approach. The clinical significance of the body compartment to be measured should be determined before a measurement method is selected, because the more advanced techniques are less accessible and more costly.

Prepubertal Asians have less limb skeletal muscle

Skeletal muscle mass in prepubertal Asian children has not been examined previously. The aims of this study were to test the hypotheses that 1) prepubertal Asians have less appendicular skeletal muscle (ASM) mass compared with African-Americans and Caucasians, and 2) ASM is less in prepubertal Asian girls compared with Asian boys. ASM was estimated by using dual-energy X-ray absorptiometry in healthy prepubertal girls (n = 170) and boys (n = 166). The results showed that, after adjusting for age, height, and body weight, 1) Asian girls and boys had less amounts of ASM than African-Americans (P < 0.001); 2) Asian girls had less amounts of ASM than Caucasian girls (P = 0.004); 3) there was a trend towards less ASM in Asian compared with Caucasian boys (P = 0.07); 4) and Asian girls had significantly less ASM than Asian boys (P < 0.001). This study indicates that skeletal muscle mass as a fraction of body weight is smaller in Asian compared with African-American and Caucasian children.

The prevalence of osteopenia in pediatric renal allograft recipients varies with the method of analysis

BACKGROUND

Pediatric renal allograft recipients often suffer from osteopenia and the potential for increased fractures. Although modern densitometers are widely available, their use in children is complicated by lack of optimal interpretive criteria.

METHODS

We reviewed dual energy X-ray absorptiometry (DEXA) studies in 33 patients with functional renal allografts 4.4 +/- 3.6 years after transplantation. We interpreted our data using three previously described methods of assigning bone mineral density (BMD) Z scores.

RESULTS

BMD was directly related to age, height, weight, body surface area, and pubertal status (p < 0.001). Using gender-mixed reference data matched by chronological age, the mean BMD Z score was -0.9 +/- 1.3 vs. 0.4 +/- 1.4 when matched by height-age (p < 0.001). Height-age adjustment particularly increased the BMD Z score of pubertal adolescents. In a subset of 22 patients, gender-matched reference data led to different results from the gender-mixed reference population (mean BMD Z score 0.0 +/- 1.7 vs. -0.8 +/- 1.4, p < 0.001).

CONCLUSIONS

The perceived prevalence of osteopenia among pediatric kidney transplant recipients differs using analysis based on chronological age, height-age, or gender-matched reference data. Further studies are necessary to determine the clinical significance of measured bone density in this population.

Human body composition: in vivo methods

In vivo methods used to study human body composition continue to be developed, along with more advanced reference models that utilize the information obtained with these technologies. Some methods are well established, with a strong physiological basis for their measurement, whereas others are much more indirect. This review has been structured from the methodological point of view to help the reader understand what can be examined with each technique. The associations between the various in vivo methods (densitometry, dilution, bioelectrical impedance and conductance, whole body counting, neutron activation, X-ray absorptiometry, computer tomography, and magnetic resonance imaging) and the five-level multicompartment model of body composition are described, along with the limitations and advantages of each method. This review also provides an overview of the present status of this field of research in human biology, including examples of reference body composition data for infants, children, adolescents, and adults.