Body-Fat-Percentile Curves for Thai Children and Adolescents

This study aimed to generate sex-specific percentile curves for the percentage of body fat (PBF) in Thai children using a bioelectrical impedance analysis (BIA). The secondary objective of this study was to determine the association between body fat and other anthropometric measurements. A cross-sectional study was conducted on 3455 Thai school children aged 6-18 years. The body-fat contents were measured using BIA. Smoothed percentile curves of PBF were derived using a scatter plot with a smooth curve fitted by the Loess method. The correlations between the body fat and the anthropometric measurements were assessed using the Spearman's rank correlation. The 50th and lower body-fat-percentile curves of the boys slowly increased until age 12, after which they slightly decreased until age 15 and then slightly increased until age 18. In the higher boys' percentiles, the body fat sharply increased until age 11 and then decreased until age 18. In the girls, the PBF percentiles increased steadily from 6 to 18 years. The body-mass index was strongly correlated with PBF and fat mass in both sexes. The waist-to-height ratios showed strong correlations with PBF and fat mass in the boys but were moderate in the girls. The use of PBF percentile curves can be an additional metric for the evaluation of obesity in Thai children.

Assessment of fetal heart aortic and pulmonary valve annulus area by three-dimensional ultrasonography: reference curves and applicability in congenital heart diseases

OBJECTIVES

To determine reference curves for fetal aortic and pulmonary valve annulus area by three-dimensional ultrasonography using the spatio-temporal image correlation (STIC) in the rendering mode, and to ascertain its applicability in congenital heart disease (CHD).

METHODS

We performed a retrospective cross-sectional study of 328 normal fetuses and 42 fetuses with CHD between 20 and 33 weeks 6 days of gestation. The outflow plane view of the great vessels was used to measure the areas of the valvar annuli, and the measurements were performed in systole. A linear regression model adjusted according to the determination coefficient (R²) was utilized to construct the reference intervals. The concordance correlation coefficient (CCC) was used to calculate the reproducibility of the mitral and tricuspid valve areas.

RESULTS

The mean ± standard deviation (SD) of the aortic and pulmonary valve annulus areas ranged from 6.6 ± 1.2 to 32.9 ± 1.1 mm² and 10.7 ± 1.3 to 40.3 ± 1.2 mm², respectively. We observed a linear relationship and strong positive correlation between the area of the aortic and pulmonary valve annuli with r=0.97 and 0.96, respectively. Good intra (CCC=0.99) and interobserver agreement (CCC=0.98) was observed for the measurement of the aortic valve annulus area. A good intra (CCC=0.99) and interobserver (CCC=0.97) agreement was also observed for the measurement of the pulmonary valve annulus area. The mean ± SD of the difference of the areas of the aortic and pulmonary valve annuli between the normal fetuses and those with CHD were -1.801 ± 1.429 mm² (p=0.208) and -1.033 ± 1.467 mm² (p<0.0001), respectively.

CONCLUSIONS

The reference curves for the areas of the aortic and pulmonary valve annuli of fetal hearts were determined, and showed good inter and intraobserver reproducibility. The constructed reference curves showed applicability in different types of CHD.

Reference curves for the normal fetal small bowel and colon diameters; their usefulness in fetuses with suspected dilated bowel

Objectives: To establish reference curves of normal fetal small bowel and colon diameters and to assess the clinical applicability.Method: Serial longitudinal ultrasound examinations at 4-week intervals between 20 to 41 weeks of gestation in 39 low-risk fetuses. The largest loop of the small bowel and colon was identified. The bowel lumen short axis was measured. Linear mixed modeling was used to determine individual developmental trajectories. Twenty-eight fetuses with suspected bowel dilatation were analyzed relative to the reference curves.Results: Development of the small bowel and colon diameters was best described by a linear and cubic model, respectively. The intraobserver and interobserver concordance were >0.94. In cases with suspected bowel dilatation, normal fetal outcome occurred if the bowel dilatation was transient. Progressive increase of fetal bowel diameter was associated with pathology after birth. Cases with small bowel pathology had a z-score >8 after 25 weeks of gestation.Conclusion: We provided the first ultrasound reference curves for normal fetal small bowel and colon diameters. Progressive increase in the fetal bowel diameter z-score was highly predictive of intestinal abnormalities after birth. Longitudinal follow-up of dilated fetal bowel is important to distinguish normality from disease.

Body fat in children and adolescents participating in organized sports: Descriptive epidemiological study of 6048 Latvian athletes

BACKGROUND

Pressure among young athletes to meet body composition goals may lead to poor nutrition and affect growth.

AIMS

To examine the proportion of body fat (%BF), measured by bioimpedance analysis, among Latvian children and adolescents participating in organized sports.

METHODS

Our study had a nationally representative sample of 6048 young athletes, aged 10-17 years. Their %BF was measured using a multifrequency, 8-pole, bioelectrical impedance leg-to-hand analyzer.

RESULTS

About 19.2% (CI 14.4-20.0) of boys and 15.1% (CI 14.0-16.3) of girls had a %BF value below the recommended levels. The %BF in young female athletes participating in aesthetic sports was lower than among their peers participating in other sports. Young male athletes participating in aesthetic sports had lower %BF levels at 10 and 12 years of age, compared with participants in weight-class sports; and lower levels of %BF from age 10-14 years, compared with participants in non-weight-sensitive sports.

CONCLUSIONS

Almost every fifth child and adolescent participating in organized sports displayed critically low body fat levels. Body fat needs to be assessed regularly in young athletes, to prevent negative consequences on health.

Percentiles of percentage body fat in german children and adolescents: an international comparison

Background:

Age- and gender-specific percentiles of body mass index in children and adolescents are a cornerstone categorizing overweight and obesity in youths worldwide. Since corresponding worldwide growth curves of percent body fat (% BF) are missing, the purpose was to contribute smoothed percentiles of percentage body fat from a large urban sample of German youths and to include them in actual national and international percentile curves.

Methods:

We estimated % BF in 22 113 German youths aged 3 to 18 years participating in yearly cross-sectional surveys of the PEP Family Heart Study Nuremberg between 1993 and 2007. Percentage body fat was calculated from skinfold thickness using Slaughter equations. Ten smoothed percentile curves were constructed for % BF using the LMS method significant.

Results:

The age- and gender-specific reference curves demonstrate a continuous age-dependent increase of percentage body fat from age 3 to 18 years in girls; whereas in boys, the percentile curves steeply increase from 5 to 11 years and thereafter slightly decrease. The shape of the percentile curves, the maxima among boys at puberty and the median % BF at age 18 years are consistent with most of the current growth curves. % BF in urban studies seems to be lower than in national surveys .

Conclusions:

More than these nine studies should contribute to worldwide-standardized growth charts for % BF to better define overweight and obesity in youth.