A novel approach to assess body composition in children with obesity from density of the fat-free mass.

BACKGROUND & AIMS: Assessment of Fat Mass (FM) and fat-free mass (FFM) using Air-displacement plethysmography (ADP) technique assumes constant density of FFM (DFFM) by age and sex. It has been recently shown that DFFM further varies according to body mass index (BMI), meaning that ADP body composition assessments of children with obesity could be biased if DFFM is assumed to be constant. The aim of this study was to validate the use of the calculations of DFFM (rather than constant density of the FFM) to improve accuracy of body composition assessment in children with obesity. METHODS: cross-sectional validation study in 66 children with obesity (aged 8-14 years) where ADP assessments of body composition assuming constant density (FFMBODPOD and FMBODPOD) were compared to those where DFFM was adjusted in relation to BMI (FFMadjusted and FMadjusted), and both compared to the gold standard reference, the 4-component model (FFM4C and FM4C). RESULTS: FFMBODPOD was overestimated by 1.50 kg (95%CI -0.68 kg, 3.63 kg) while FFMadjusted was 0.71 kg (-1.08 kg, 2.51 kg) (percentage differences compared to FFM4C were 4.9% (±2.9%) and 2.8% (±2.1%), respectively (p < 0.001)). Consistently, FM was underestimated by both methods, representing a mean difference between methods of 4.0% (±2.9%) and 6.8% (±3.8%), respectively, when compared to the reference method. The agreement and reliability of body composition assessments were improved when adjusted using calculations (adjusted models) rather than assuming constant DFFM. CONCLUSIONS: The use of constant values for fat-free mass properties may increase bias when assessing body composition (FM and FFM) in children with obesity by two-component techniques such as ADP. Using adjusted corrections as proposed in the present work may reduce the bias by half.

Bifidobacterium longum subsp infantis CECT7210-supplemented formula reduces diarrhea in healthy infants: a randomized controlled trial.

BackgroundIntestinal microbiota of breast-fed infants is plenty of beneficial bifidobacteria. We aimed to determine whether an infant formula supplemented with probiotic Bifidobacterium longum subsp. infantis CECT7210 (B. infantis IM1) is effective at reducing diarrhea incidence in healthy term infants.MethodsDouble-blinded, randomized, multicenter, controlled clinical trial, where formula-fed infants (<3 months) received an infant formula supplemented (Probiotic) or not (Control) with 107 cfu/g of B. infantis IM1 over 12 weeks. Diarrheas, growth, digestive symptoms, stool bifidobacteria, and microbiota were assessed.ResultsIn all, 97 (Control) and 93 (Probiotic) infants were randomized, and 78 (Control) and 73 (Probiotic) completed the 12 week-follow-up. In the overall study period, a median of 0.29±1.07 and 0.05±0.28 diarrhea events/infant was observed in the Control and Probiotic groups, respectively (P=0.059). This trend to less diarrhea episodes in the Probiotic group reached statistical significance at 8 weeks (0.12±0.47 vs. 0.0±0.0 events/infant, P=0.047). Constipation incidence was higher (odds ratio (OR) 2.67 (1.09-6.50)) and stool frequency lower (2.0±1.0 vs. 2.6±1.3 stools/day, P=0.038) in the Control group after 4 weeks. No differences were found at other time points nor in other digestive symptoms, growth, or formula intake.ConclusionA B. infantis IM1-supplemented infant formula may reduce diarrhea episodes, being safe, well tolerated, and associated with lower constipation prevalence.

Influence of Feeding Types during the First Months of Life on Calciuria Levels in Healthy Infants: A Secondary Analysis from a Randomized Clinical Trial.

BACKGROUND/AIMS: Dietary factors can modify calciuria. We aim to investigate urinary calcium excretion in healthy infants according to their protein. METHODS: Secondary data analysis from a randomized clinical trial where healthy term infants were randomized after birth to a higher (HP) or lower (LP) protein content formula that was consumed until age 1 year. A non-randomized group of breastfed (BF) infants was used for reference. Anthropometry, dietary intakes and calciuria (calcium/creatinine ratios) from spot urine samples were assessed at ages 3 and 6 months. At 6 months, the kidney volumes were assessed using ultrasonography, and the serum urea and creatinine levels were determined. RESULTS: BF infants showed the highest calciuria levels, followed by the HP and the LP groups (p < 0.001 for all comparisons). Either protein intakes or formula types modulated the calciuria in linear regression models adjusted for other influencing dietary factors. The usual cut-off values classified 37.8% (BF), 16.8% (HP) and 4.9% (LP) of the infants as hypercalciuric. CONCLUSIONS: Feeding types during the first months of life affect calciuria, with BF infants presenting the highest levels. We propose new cut-off values, based on feeding types, to prevent the overestimation in hypercalciuria diagnoses among BF infants.

Reduced bone mass in 7-year-old children with asymptomatic idiopathic hypercalciuria.

BACKGROUND: Idiopathic hypercalciuria (IHC), i.e. an elevated urinary calcium excretion without concomitant hypercalcemia, is a common disorder in children and can have a range of urinary clinical presentations and decreased bone mineral density (BMD). AIM: To assess the effect of IHC on bone mineral content in children without urological symptoms. METHODS: Calcium excretion, BMD (by dual-energy X-ray absorptiometry), and anthropometry were assessed in 175 seven-year-old children who were classified as IHC or controls. Calcium intake and physical activity were measured as confounding factors. RESULTS: The prevalence of IHC was 17.7%. Both groups (controls and IHC) showed similar baseline characteristics in terms of their anthropometry, gender distribution, and protein and calcium dietary intakes as well as physical activity scores. Urinary calciuria was independent of the calcium dietary intake and anthropometry. BMD correlated with anthropometry and physical activity but not with calcium dietary intake. IHC children had lower whole-body BMD z-scores compared to controls. The role of IHC in reducing the whole-body BMD z-score was still significant even when anthropometry, physical activity, and calcium intake were included as confounders in multivariate analyses. CONCLUSIONS: The prevalence of IHC in this population of 7-year-old children was about 17%. IHC diagnosis was associated with lower BMD z-scores and osteopenia in 22% of them.

Bioimpedance in 7-year-old children: validation by dual X-ray absorptiometry - part 2: assessment of segmental composition.

AIM: Segmental body composition in children was assessed using the bioimpedance analyzer (BIA) TANITA BC-418 and compared with dual-energy X-ray absorptiometry (DXA) values. METHODS: A cross-sectional validation study in which 7-year-old children from the Spanish subsample of the EU Childhood Obesity Project were assessed through anthropometry, BIA and DXA. Main outcome measures were fat and lean masses of the trunk, left arm and left leg (in kg) assessed through BIA direct outputs (BIAoutputs) and DXA. Predictive equations for the composition of each segment were derived from raw impedance and anthropometric measurements; results obtained from these predictive equations (BIAregressions) were also compared to DXA. RESULTS: One hundred seventy-one (84 boys) 7-year-old children were studied. BIAoutputs and DXA results showed small differences for leg lean mass (6.5%) and high differences for trunk fat and trunk lean masses (>30%). BIAregressions results showed differences of about 20% for trunk fat mass, 1.5% for trunk lean mass and 3.7% for leg lean mass compared to DXA. CONCLUSIONS: Segmental body composition measures predicted by internal algorithms of the TANITA BC-418 were not valid for clinical or epidemiological use, except for leg lean mass. The assessment of segmental composition was improved using our own predictive equations combining segmental-specific anthropometric measurements with segmental impedances.

Bioimpedance in 7-year-old children: validation by dual X-ray absorptiometry - part 1: assessment of whole body composition.

AIM: To validate the bioimpedance analyzer (BIA) Tanita BC-418 for its clinical and epidemiological use in children compared to dual-energy X-ray absorptiometry (DXA). METHODS: A cross-sectional validation study was performed in 7-year-old children using anthropometry, BIA and DXA. Whole body fat and lean masses were assessed through BIA (BIAoutputs) and DXA. Fat mass index (FMI) was calculated. Predictive equations were derived from raw impedance and anthropometric measures; results obtained from these predictive equations (BIAregressions) were also compared to DXA. RESULTS: 171 children (84 boys) were studied. BIAoutputs and DXA results revealed small differences for lean mass (1%) and moderate differences for fat mass (13%). BIAregressions results showed small differences for both body lean and fat masses (0.21 and 4.62%, respectively). Sensitivity and specificity to correctly classify children >90.8th percentile of FMI was 84.6 (64.3-94.9) and 95.9% (90.8-98.3) for BIAoutputs and 100 (98.1-100.0) and 95.9% (92.3-99.4) for BIAregressions, respectively. CONCLUSIONS: Tanita BC-418 may be valid for epidemiological studies assessing whole body composition. Its measurements may help in the diagnosis and monitoring of childhood overweight and obesity. The validation of predictive equations in specific populations may increase the precision of the technique.