Waist-to-height ratio as a measure of abdominal obesity in southern Chinese and European children and adolescents.

BACKGROUND: Waist-to-height ratio (WHtR), with a 0.5 threshold (WHtR0.5), is regarded as a simple age- and gender-independent criterion of abdominal obesity (AO) and a better predictor than the 90th percentile of waist circumference (WCP90). OBJECTIVE: An analysis of gender and ethnic differences of WHtR and other AO indices between children and adolescents from southern China (HK: Hong-Kong, China) and Europe (LD: Lódz, Poland). SUBJECTS: Two large cross-sectional surveys of children and adolescents aged 7-19 years, one from LD (13 172) and one from HK (14 566). METHODS: The percentile and standardized values of WHtR and other parameters (WC, body mass index (BMI)) were assessed using the LMS method. The WHtR values corresponding to WCP90 and to the BMI definition of global obesity (BMIP95) were evaluated with the polynomial regression model. The compliance of the AO prevalence data, obtained with two criteria (WCP90 vs WHtR0.5) was analyzed using Cohen's kappa index (κC). RESULTS: The WHtR data of Polish subjects were generally higher than those of their HK peers, and the ethic differences increased with age. The WHtR values of HK boys showed a stronger relationship with BMI z-score. WHtR corresponding to WCP90 assumed values <0.5. An application of Cohen's kappa coefficient (κC) to Polish subjects showed either 'substantial' (κC>0.6) or 'almost perfect' (κC>0.8) agreement in the AO prevalence for both criteria (WCP90 and WHtR0.5). For these criteria, either 'fair' (κC <0.4) or 'moderate' (κC<0.6) AO consistency ratings were observed among HK girls. In HK boys, a significant difference in the prevalence of AO was observed, independent of the criterion used. CONCLUSIONS: Our results provide further evidence of the need for developing ethnic-specific WC charts and for recommending that a WHtR cutoff of 0.5 may not be appropriate to predict cardiometabolic risk in children of different ethnic groups.

Frequency of under- and overweight among children and adolescents during the economic transition in Poland.

The aim of this study is to examine the prevalence of underweight, overweight and obesity, using International Obesity Task Force (IOTF) criteria, in four cohorts of children and adolescents living in Poland in different economic eras: communist economy (1977/1978), crisis of the 1980s (1987/1988), political and economic transformation (1992/1994) and the free market economy (2002/2004). Analysis was conducted on a database including 10,934 records for children of the age 7-18 years. In Poland, in the last 26 years of economic and political transformations, the epidemic of obesity was not noticed but the growing incidence of children and adolescents with body mass deficit was observed (p<0.0001) (20.2% of girls in 2002/2004 vs. 11.0% in 1977/1978 and 12.1% of boys in 2002/2004 vs. 7.2% in 1977/1978). Lower parental education and a higher number of children in a family resulted in a higher prevalence of underweight (odds ratio [OR] fluctuated from 1.26 to 1.63). The social effects of the political transformation in Poland significantly affected families with low socio-economic status (SES), and especially more eco-sensitive boys. This result is opposite to the trends observed in Western countries and makes an important contribution to the current knowledge of the course of further changes in weight-to-height ratio at a global scale.

Percentile distributions of waist circumference for 7-19-year-old Polish children and adolescents.

The aim of the study was to develop waist circumference (WC) percentiles in Polish children and youth and to compare these with the results obtained in other countries. The study comprised a random group of 5663 Polish children aged 7-18 years. Smoothed WC percentile curves were computed using the LMS method. The curves displaying the values of the 50th (WC(50)) and the 90th (WC(90)) percentile were then compared with the results of similar studies carried out in children from the UK, Spain, Germany, Turkey, Cyprus, Canada and the USA. WC increased with age in both boys and girls and in all observed age periods the boys were seen to dominate. For 18-year-old Polish boys and girls the values of WC(90) were 86.5 and 78.2, respectively, and were lower than the current criteria developed by the International Diabetes Federation. Both WC(50) and WC(90) were higher in Polish boys and girls compared with their counterparts in the UK, Turkey and Canada and significantly lower than in children from the USA, Cyprus and Spain. The percentile curves for Polish children and youth, which were developed here for the first time, are base curves that can be applied in analysing trends as well as making comparisons with results of similar studies performed in other countries.

[Application of computer base standards to pediatrics practice]. / Wykorzystanie komputerowej bazy norm pediatrycznych w praktyce.

The computer base of medical standards to aid of pediatric diagnostic has been presented. The base include of anthropometric data (height and mass of body, some of circumferences, thickness of skinfolds etc.), analytical data (lipids) and also some of hemodynamic parameters (blood pressure). The programme allows graphical presentation of data as a percentile charts and also archives data. The basic of construction of computer base and examples of application has been presented.

Impact of cardiovascular reactions using the impedance cardiography method in borderline hypertension.

This paper evaluates the hemodynamics of 30 young men, aged 17-19 years, with borderline hypertension (BHT) and 29 normotensive (NT) patients within the same age range. The study has been carried out using the impedance cardiography method at rest and under passive orthostatic test, cold test, and hyperventilation test. In the BHT patients, the following features have been observed: increased values of the cardiac index (CI), stroke volume index (SVI), mean blood pressure (MBP), and left ventricle work index (LVWI), as well as the accompanying normal values of the total peripheral resistance index (TPRI). The reactions of the cardiovascular systems during the functional tests are similar in both tested groups; however, they are most clearly distinct in the BHT patients, where the differences are statistically significant. This may support the argument that the activity of the adrenergic system in this group in intensified.

A computer aided venous occlusion plethysmography.

A computer aided set of equipment for impedance plethysmographic research has been presented. A simple linear model of blood circulation in a limb has been used. A comparative analysis of blood circulation parameters in lower extremities has been carried out manually as well as calculated automatically. Parameters such as the limb blood flow Qo, the tissue blood flow qo, maximum volume change (venous capacitance, VC), the venous outflow time constant Tv and the venous outflow index were automatically and traditionally calculated on the basis of curve lines recorded on thermal recorder. A high linear correlation has been observed between parameters calculated manually and with computer-aided techniques. The results obtained confirm the usefulness of the linear model of blood circulation in a limb for pressures occurring under the conditions of vein occlusion.

[Rheography of the upper extremity in the diagnosis of vibration-induced vascular disorders]. / Reografia konczyny górnej w diagnostyce powibracyjnych zaburzen naczyniowych.

The possibilities of impedance rheography in the diagnosis of the vascular form of the vibration syndrome have been presented. Three groups have been covered by the investigation: controls, subjects in occupational significant exposure to local vibration and subjects with the diagnosed vascular vibration syndrome. The rheographic investigations have been carried out synchronically from the area of hand fingers and forearms as well as under a positional test (arm elevation). Analysis of the relative pulse rate accounts for differentiating workers in the test groups. The findings confirm that the methods applied in the rheographic investigations may be a practical importance in the diagnosis of the vibration syndrome.

[Use of impedance rheography in the diagnosis of the vibration syndrome]. / Zastosowanie reografii impedancyjnej w diagnostyce zespolu wibracyjnego.

Each new method of studies yielding objective information on functioning disorders of those organs that get disturbed earliest is valuable for early diagnosis of vibration disease. The paper is an attempt of evaluating the usefulness of impedance reography in the diagnosis of the vibration syndrome. Analysis of basic reographic indices performed after examinations of fingers implies statistically significant differences between controls and those occupationally exposed to vibration transmitted to upper limbs.