Sirinuch Chomtho

Pediatric reference data for lean tissue properties: density and hydration from age 5 to 20 y

BACKGROUND Hydrometry and densitometry are widely used to assess pediatric body composition due to their ease of application. The accuracy of these techniques depends on the validity of age- and sex-specific constant values for lean tissue hydration or density. Empirical data on these constants, and their variability between individuals, are lacking. OBJECTIVES The objectives were to measure lean tissue hydration and density in a large sample of children and adolescents and to derive prediction equations. DESIGN Body composition was measured in 533 healthy individuals (91% white) aged 4-23 y by using the 4-component model. Age- and sex-specific median values for hydration and density were obtained by using the LMS (lambda, mu, sigma) method. Regression analysis was used to generate prediction equations on the basis of age, sex, and body mass index SD score (BMI SDS). Values were compared with those in previously published predictions. RESULTS Age-associated changes in density and hydration differed between the sexes. Compared with our empirical values, use of published values resulted in a mean bias of 2.1% fat (P < 0.0001). Age, sex, and BMI SDS were all significant predictors of lean tissue hydration and density. With adjustment for age and sex, hydration was higher, and density lower, in higher-BMI SDS individuals. CONCLUSIONS The chemical maturation of lean tissue is not a linear process and proceeds differently in males and females. Previously published reference values are inaccurate and induce clinically significant bias in percentage fat. New empirical reference values are provided for use in pediatric hydrometry and densitometry. Further research that extends to cover nonwhite ethnic groups is needed.

Body-composition reference data for simple and reference techniques and a 4-component model: a new UK reference child

BACKGROUND A routine pediatric clinical assessment of body composition is increasingly recommended but has long been hampered by the following 2 factors: a lack of appropriate techniques and a lack of reference data with which to interpret individual measurements. Several techniques have become available, but reference data are needed. OBJECTIVE We aimed to provide body-composition reference data for use in clinical practice and research. DESIGN Body composition was measured by using a gold standard 4-component model, along with various widely used reference and bedside methods, in a large, representative sample of British children aged from 4 to ≥20 y. Measurements were made of anthropometric variables (weight, height, 4 skinfold thicknesses, and waist girth), dual-energy X-ray absorptiometry, body density, bioelectrical impedance, and total body water, and 4-component fat and fat-free masses were calculated. Reference charts and SD scores (SDSs) were constructed for each outcome by using the lambda-mu-sigma method. The same outcomes were generated for the fat-free mass index and fat mass index. RESULTS Body-composition growth charts and SDSs for 5-20 y were based on a final sample of 533 individuals. Correlations between SDSs by using different techniques were ≥0.68 for adiposity outcomes and ≥0.80 for fat-free mass outcomes. CONCLUSIONS These comprehensive reference data for pediatric body composition can be used across a variety of techniques. Together with advances in measurement technologies, the data should greatly enhance the ability of clinicians to assess and monitor body composition in routine clinical practice and should facilitate the use of body-composition measurements in research studies.

Evaluation of Arm Anthropometry for Assessing Pediatric Body Composition: Evidence from Healthy and Sick Children

Arm anthropometry is used as a proxy of body composition in clinical and field research but its validity has not been established in children. To address this issue, mid-upper arm circumference (MUAC) and triceps skinfold thickness (TS) were measured in 110 healthy children aged 4.4–13.9 y (55 boys) and 49 cystic fibrosis (CF) patients aged 8.1–13.4 y (22 boys). Reference values were arm and whole-body fat mass (FM) and fat-free mass (FFM) measured by dual x-ray absorptiometry and four-component model, respectively. Arm fat area (AFA), MUAC, and TS correlated well with arm FM (r = 0.84–0.92) and total FM (r = 0.78–0.92). Arm muscle area (AMA) and MUAC correlated well with arm FFM (r = 0.68–0.82) and total FFM (r = 0.60–0.86). After adjusting for age, sex, and height, arm anthropometry correlated strongly with FM but weakly with FFM. AFA, MUAC, and TS explained 67, 63, and 61% of variability in total FM in healthy children and 70, 72, and 63% in CF. AMA and MUAC explained only 24 and 16% of variability in total FFM in healthy children and 33 and 28% in CF. Arm anthropometry is useful for predicting FM and ranking healthy children and patients for fatness. It has poorer success in predicting regional or total FFM.

Undercarboxylated osteocalcin and bone mass in 8–12 year old children with cystic fibrosis ☆

UNLABELLED Young adults with cystic fibrosis (CF) frequently develop bone disease. One suggested aetiological factor is suboptimal vitamin K status with impaired carboxylation of osteocalcin and abnormal bone formation. METHODS We measured bone mineralization and turnover in thirty-two 8-12 year old CF patients (14 boys) using Dual Energy X-ray absorptiometry (whole body (WB) and lumbar spine (LS)), 25-OH Vitamin D, PTH and markers of bone formation (plasma osteocalcin, N-terminal pro-peptide of type 1 collagen (P1NP)), plus an indirect measure of vitamin K status, undercarboxylated osteocalcin (uc-OC). RESULTS LS bone mineral density (BMD) standard deviation (SD) scores were < -1.0 in 20% of subjects. Size-adjusted LS and WB bone mass was normal. Compared to reference data, % uc-OC was high and P1NP low. LS bone mass was predicted by % uc-OC but not other markers (0.4% decrease in size-adjusted LSBMC (p=0.05); 0.04 SD decrease in LSBMAD (p=0.04) per 1% increase in uc-OC). CONCLUSION Markers suggestive of sub-optimal vitamin K status and low bone formation were present despite normal size-adjusted bone mass. The association between LSBMC and % uc-OC is consistent with the hypothesis that sub-optimal vitamin K status is a risk factor for CF bone disease. This should ideally be investigated in an intervention trial.

Growth and bone health in pediatric intestinal failure patients receiving long-term parenteral nutrition

BACKGROUND Children with chronic intestinal failure (IF) treated with long-term parenteral nutrition (PN) may present with low bone mineral density (BMD). The cause may reflect small body size or suboptimal bone mineralization. OBJECTIVE We assessed growth and bone health in children with severe IF. DESIGN Height, weight, and fracture history were recorded. The lumbar spine bone mass was measured in 45 consecutive patients (24 male subjects) aged 5-17 y receiving PN for a median of 5 y. BMD and bone mineral apparent density (BMAD) [ie, adjusted-for-height SD scores (SDSs)] were calculated. RESULTS Diagnoses were short bowel syndrome in 12 patients (27%), intestinal enteropathy in 20 patients (44%), and motility disorder in 13 patients (29%). Mean (±SD) weight, height, and body mass index SDSs were -0.8 ± 1.3, -1.80 ± 1.5, and 0.4 ± 1.3, respectively. The height SDS was less than -2 in 23 children (50%). Patients with enteropathy or intestinal mucosal inflammation (associated with dysmotility or short bowel) were significantly shorter than patients without enteropathy (P = 0.007). The BMD SDS was -1.7 ± 1.6, and the BMAD SDS was -1.4 ± 1.5, independent of primary diagnosis or mucosal inflammation. Nineteen patients (42%) had low BMD (SDS less than -2.0), and 14 patients (31%) had low BMAD. In 25 patients studied at 1-2-y intervals, the BMD SDS fell significantly with time, whereas BMAD declined less, which suggested that a poor bone mineral accretion reflected poor growth. A total of 11 of 37 patients (24%) had nonpathologic fractures (P = 0.3 compared with the general population). CONCLUSIONS Approximately 50% of children were short, and one-third of children had low BMD and BMAD. Children with enteropathy or intestinal mucosal inflammation are at greatest risk of growth failure. Close nutritional monitoring and bespoke PN should maximize the potential for growth and bone mass.

Early Growth and Body Composition in Infancy

UNLABELLED Examination of the relationship between early growth and body composition (BC) in infancy might provide clues about the mechanism of early nutrition programming. 150 healthy full-term infants (64 boys) born in Cambridge from 1985-1993 had BC measured using stable isotope at the age of 12 weeks as a part of infant nutrition studies. Fat mass index (FMI, FM/length(2)) and lean mass index (LMI, LM/length(2)) internal standard deviation scores (SDS) were calculated for boys and girls. Birth weight SDS was positively associated with length, BMI and FMI SDS at 12 weeks, but not LMI SDS; equivalent to 0.26 SDS increase in FMI per 1 SDS increase in birth weight (95% CI, 0.04-0.48). Weight SDS change from birth-12 weeks was positively correlated with FMI and LMI SDS at 12 weeks; equivalent to 0.68 SDS and 0.48 SDS increase in FMI and LMI per 1 SDS gain in weight (95% CI, 0.48-0.88 and 0.26-0.70, respectively). Associations were independent of gender, parity, infant diets, and, for weight gain, birth weight SDS. CONCLUSION Higher birth weight was associated with higher fat mass at 3 months whereas rapid weight gain in the first 3 months was associated with both fat and lean mass. Our data do not support the hypothesis that lean mass tracks directly from fetal life to childhood.

Composition of Follow-Up Formula for Young Children Aged 12-36 Months: Recommendations of an International Expert Group Coordinated by the Nutrition Association of Thailand and the Early Nutrition Academy

Background: There are no internationally agreed recommendations on compositional requirements of follow-up formula for young children (FUF-YC) aged 1-3 years. Aim: The aim of the study is to propose international compositional recommendations for FUF-YC. Methods: Compositional recommendations for FUF-YC were devised by expert consensus based on a detailed literature review of nutrient intakes and unmet needs in children aged 12-36 months. Results and Conclusions: Problematic nutrients with often inadequate intakes are the vitamins A, D, B12, C and folate, calcium, iron, iodine and zinc. If used, FUF-YC should be fed along with an age-appropriate mixed diet, usually contributing 1-2 cups (200-400 ml) of FUF-YC daily (approximately 15% of total energy intake). Protein from cows milk-based formula should provide 1.6-2.7 g/100 kcal. Fat content should be 4.4-6.0 g/100 kcal. Carbohydrate should contribute 9-14 g/100 kcal with >50% from lactose. If other sugars are added, they should not exceed 10% of total carbohydrates. Calcium should provide 200 mg/100 kcal. Other micronutrient contents/100 kcal should reach 15% of the World Health Organization/Food and Agriculture Organization recommended nutrient intake values. A guidance upper level that was 3-5 times of the minimum level was established. Countries may adapt compositional requirements, considering recommended nutrient intakes, habitual diets, nutritional status and existence of micronutrient programs to ensure adequacy while preventing excessive intakes.

Body composition in paediatric intestinal failure patients receiving long-term parenteral nutrition

Objective Outcome of children with intestinal failure (IF) has improved on treatment with parenteral nutrition (PN). The effects of PN and IF on body composition (BC) are unknown. The aim was to review BC in PN-treated children and those weaned off and to compare with reference data. Design Children on long-term/home PN underwent measurement of regional fat mass (FM) and lean mass (LM) using dual energy X-ray absorptiometry. Underlying diseases were intestinal enteropathy, n=15, short bowel syndrome (SBS), n=8 and intestinal dysmotility, n=11. PN duration was median 10 years. Fat Mass Index (FMI) and Lean Mass Index (LMI) were compared in children with and without intestinal inflammation, steroid treatment and according to PN dependency. Results 34 children aged 5–20 years were studied. They were short, mean height SD score (SDS) −1.8 (p<0.001) and light (mean weight SDS −0.86, p<0.001) with high body mass index (BMI) SDS: mean 0.4 (p=0.04) and low Limb LMI SDS −0.9 (p<0.001). Children with SBS had low FMI SDS −0.8 (p=0.01). BC did not significantly differ between diagnostic groups or with steroid treatment. Patients with intestinal inflammation (n=20) had higher BMI SDS than those without, p=0.007. Totally, PN-dependent children, n=11 had higher BMI SDS, p=0.004, total body FMI SDS, p=0.008 and trunk FMI SDS, p=0.001 compared with patients partially dependent and off PN. Conclusions Significantly low limb LM was seen in all patient groups with high FM in children on total PN. Children with IF requiring PN treatment >27 days may benefit from BC monitoring and PN adjustment according to results in order to maximise linear growth and health in later life.

Low-glycemic index diet may improve insulin sensitivity in obese children

BACKGROUND:A low-glycemic index (GI) diet may be beneficial for weight management due to its effect on insulin metabolism and satiety.METHODS:Obese children aged 9–16 y were randomly assigned either a low-GI diet or a low-fat diet (control group) for 6 mo. Body composition changes were measured by dual-energy X-ray absorptiometry and bioelectrical impedance analysis. Insulin sensitivity was measured by fasting plasma glucose and insulin.RESULTS:Fifty-two participants completed the study (mean age: 12.0 ± 2.0 y, 35 boys); both groups showed significantly decreased BMI z-score but similar changes in fat and fat-free mass. The low-GI group demonstrated a significant decline in fasting plasma insulin (22.2 ± 14.3 to 13.7 ± 10.9 mU/l; P = 0.004) and homeostatic model of assessment-insulin resistance (4.8 ± 3.3 to 2.9 ± 2.3; P = 0.007), whereas the control group did not. However, general linear model showed no significant difference in insulin resistance between groups after adjusting for baseline levels, suggesting that the greater reduction in insulin resistance in the low-GI group may be explained by higher baseline values.CONCLUSION:Despite subtle effects on body composition, a low-GI diet may improve insulin sensitivity in obese children with high baseline insulin. A bigger study in obese children with insulin resistance could be worthwhile to confirm our findings.

Age-Related Reference Intervals for Blood Amino Acids in Thai Pediatric Population Measured by Liquid Chromatography Tandem Mass Spectrometry

Background Age, race, and analytic method influence levels of blood amino acids, of which reference intervals are required for the diagnosis and management of inherited metabolic disorders. Objectives To establish age-specific reference intervals for blood amino acids in Thai pediatric population measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Methods A cross-sectional study of 277 healthy children from birth to 12 years was conducted. Anthropometric, clinical, and dietary information were recorded. Dried blood spots on a filtered paper were used for measurement by derivatized LC-MS/MS. Factors that might affect amino acids such as fasting time and dietary intake were analyzed using quantile regression analysis. Results Levels of thirteen blood amino acids were reported as median and interval from 2.5th–97.5th percentiles. Compared with those of Caucasian, most blood amino acid levels of Thai children were higher. Compared with a previous study using HPLC in Thai children, many amino acid levels are different. Glycine, alanine, leucine/isoleucine, and glutamic acid sharply decreased after birth. Citrulline, arginine, and methionine stayed low from birth throughout childhood, whereas phenylalanine was at middle level and slightly increased during preadolescence. Conclusion Reference intervals of age-specific blood amino acids using LC-MS/MS were established in the Thai pediatric population. They diverge from previous studies, substantiating the recommendation that, for the optimal clinical practice, age-specific reference intervals of amino acids should be designated for the particular population and analysis method.