Waist circumference and waist-to-height ratio distributions in polish and german schoolchildren: comparative analysis

To analyze differences in the distributions of waist circumference [WC] and waist-to-height ratio [WHtR] between Polish [PL] and German [GE] children and adolescents. Two samples of children and adolescents aged 7-18 y: From PL [n = 11,326] GE [n = 8,218] participated. The two WC cut-off points [WC1 as central fat distribution and WC2 as central obesity] corresponding at age 18 to the adult criteria were determined. Furthermore, the mean WC cut-off points [WC1m, WC2m] for boys and girls aged 14-18 from both countries were evaluated. For the WHtR, values over 0.5 were used as a definition of central fat distribution. The effect of different WC and WHtR criteria on the prevalence of abdominal obesity in both study groups was evaluated. The mean and percentile values of WC and WHtR were generally higher in all German children as compared to their peers from Poland. When WC1m is used, the mean [95% CI] prevalence of central fat distribution in the 14-18 y Polish groups was lower [P < 0.05] than those from Germany [boys: 4.4% [3.6-5.2] vs. 8.9% [7.3-10.5]; girls: 10.7% [9.0-12.3] vs. 26.4% [23.2-29.6]], whereas, using the WHtR > 0.5, the results were similar for boys - 6.7% [5.9-7.5] vs. 8.5% [8.1-8.9]; they were significantly [P < 0.05] lower for Polish and German girls: 5.3% [5.0-5.6] vs. 12.7% [9.7-16.4]. The prevalence of central obesity using WC2m as a criterion in the Polish vs. German groups was as follows: [boys - 1.1% [0.8-1.4] vs. 3.1% [2.2-4.0], P < 0.05; girls - 3.1% [2.5-3.7] vs. 10.2% [8.4-12.0], P < 0.05]. The results highlight the greater central obesity associated with the German children, both in terms of WC and WHtR, in comparison to their peers from Poland. The prevalence of AO is significantly associated with the criteria used. The results demonstrate the need for the development of international WC references for pediatric subjects

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

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