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P Bláha

Publications and source records attributed to P Bláha.

At least 19 recordsLinked to original sources
PubMed2005

Two centuries of growth among Czech children and youth.

The trend of increasing height can be interpreted as a reflection of the unfolding progress of civilization. Height changes among children and adolescents are good markers of this trend. We analyze the secular trend in the heights of children and adolescents in the Czech Republic on the basis of data from anthropological surveys. The earliest height data pertain to Czech youths who attended the Military Schools in Austria in 1800-1809. Data also exist for 1895 and continue in 1951 and at 10-year intervals thereafter. Growth curves were obtained for separate age groups by fitting mean values via third-order polynomial smoothing splines. Between 1951 and 2001, the mean heights of boys and girls aged 2.5 years increased by 2.7 and 3 cm, respectively. Since 1895, the mean height of 13-year-old boys has increased by 19.4 cm, and the mean height of girls has increased by 18.3 cm.

Adolescent↗
PubMed2004

Social inequality and obesity in Czech school children.

This study uses logistic regressions to consider the effect of social factors, physical activity, meal frequency and BMI of parents on children's body mass index (BMI) values. Three thousand three hundred and sixty-two children aged 7-11 years were examined in 38 schools in the Czech Republic. Six anthropometric characteristics were assessed in 1999-2000. Most important factors influencing children's BMI values were: obesity of both or at least one of the parents, being an only child, residence in small communities, and irregular breakfasts.

Anthropometry↗
PubMed2004

The 6th nationwide anthropological survey of children and adolescents in the Czech Republic in 2001.

The 6th nationwide anthropological survey (NAS) of children and adolescents was carried out in the Czech Republic in 2001 to continue the series of surveys repeated at 10-year intervals since 1951 (with the participation of the Slovak Republic up to 1991). The major objective was to find out the following body measurements of children and adolescents: body height and weight, and head, arm, waist and hip circumferences. Questionnaires were used to find out the body measurements of parents (body height and weight) and some socio-economic characteristics of the child's family (number of siblings, education of parents, breast feeding duration, birth weight and length, child's physical activities, TV watching time, computer gaming time, etc.). A school children questionnaire focused on eating habits was also part of the survey in 2001. A total of 59,000 children aged 0.00 to 18.99 years, i.e. about 3% of the population of the same age range, were enrolled in the survey in 2001. The results obtained presented in diagrammatic and tabular forms are reference standards for monitoring growth of the Czech children and adolescents from birth to the age of 19 years. The survey revealed a substantial slowdown in the long-term trend in body height increase for both boys and girls. The most marked increase in the mean body height is currently recorded in boys at the prepubescent age while the pubescent girls show a practically zero increase for this parameter. A more marked increase in body height at the adult age is not expected any more, but the increase in body height and weight at the prepubescent age is likely to continue for some time. The 6th NAS showed a marked slow down to a stop in the trend in the mean body weight increase. No increase in the mean body weight has been recorded in pubescent girls since the 1970's and in pubescent and postpubescent boys since 1991. Nevertheless, the younger age groups, namely those of preschool and primary school children, continue to show increase in the mean body weight. The secular trend in body weight has been less pronounced compared to that in body height. The rates of overweight and obese children (as assessed by body mass index, BMI) have risen in most age groups of school children compared to those reported in 1991. In contrast, a slight decrease in the rate of overweight children can be seen in boys starting from the age of 16 years and in girls starting from the age of 13 years. The obesity prevalence rate is significantly higher in boys than girls. Statistical analysis confirmed a correlation between the BMI values in children and education of parents (the higher the education, the lower the rate of overweight children) and between the BMI values and the population size of the community where the child lives (the higher the population, the lower the prevalence rates of overweight and obesity). Single children suffer more frequently from overweight and obesity than those with siblings.

Adolescent↗
PubMed2003

Leptin levels in obese children: effects of gender, weight reduction and androgens.

Obesity in children is accompanied by increased circulating leptin concentrations. Girls have higher leptin concentrations than boys. The aim of our study was to compare serum leptin levels before and after a five-week weight reduction program and to study the relationship of leptin levels, serum total cholesterol, and androgens (testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulphate) in 33 obese boys (age: 12.7+/-1.97 years, BMI: 30.46+/-4.54) and 66 obese girls (age: 12.7+/-2.51 years, BMI: 29.31+/-4.62). We found that serum leptin concentrations in obese children were significantly decreased after a weight reduction program (before 20.79+/-9.61 ng/ml, after 13.50+/-8.65 ng/ml in girls; before 12.25+/-10.09 ng/ml and after 5.18+/-3.56 ng/ml in boys, p<0.0001 in both genders). Leptin levels correlated positively with the body mass index before and after weight reduction. There was a positive association in obese boys and a negative one in obese girls between leptin levels and the WHR (waist to hip circumference ratio). Serum leptin also shows a strong relationship to fat distribution (p=0.02 in boys, p<0.0001 in girls). No significant correlation was found between leptin concentrations and total cholesterol or androgens. We confirmed that leptin is a sensitive parameter of body composition and weight reduction in obese children.

Adolescent↗
PubMed2002

Bodily characteristics and lifestyle of Czech children aged 7.00 to 10.99 years, incidence of childhood obesity.

In 1991-2000 in the Czech Republic a survey of the prevalence of obesity was made. The assessment was made by the transversal method in elementary schools in all regions of the Czech Republic. Children aged 7.00 to 10.99 years were investigated. The survey comprised a total of 3362 children (1668 girls and 1694 boys). A total of 12 anthropometric dimensions were recorded and questionnaires addressed to the children and parents were analyzed. From the results ensued that the ratio of obese children of both sexes in the CR (i.e. children with BMI values about the 97th percentile of the reference population) increased. This zone comprised 6.0% boys and 5.6% girls of the investigated group. An important finding was also the increase of mean values of the abdominal circumference of the children in all age groups in both sexes. The ratio of obese children in different communities is related unequivocally to the size of the community., In smaller communities there are more obese children (according to our data 6.9%) and in large towns the ratio of obese children is 2.3%. In large towns there is also a greater proportion of thin children - 12.1%, in small communities 8.6%. It was found that there is a higher percentage of obese children in families where the mother has elementary education as compared with children of mothers with secondary and university education. Mothers with elementary education have 9.6% obese children while university educated mothers have only 3.6% obese children. Analysis of the dietary questionnaires revealed that only 62.9% children in large towns eat breakfast, the position in villages is similar - 63.9%. In the group of children with excessive body weight fewer children have breakfast (only 54.1%), in the group of children with a low body weigh the majority eat breakfast (75.3%). The majority of children have a mid-morning snack at school which they bring from home. As regards school lunch the majority of children from large towns replied that they have lunch at school. the number of rural children who had school lunch was smaller. An afternoon snack is taken by less than half the children in different groups.

Body Mass Index↗
PubMed2002

[Correlation of leptin and anthropometric parameters during weight reduction therapy in obese children].

At present, obesity is considered one of the major health problems. It is a predisposing factor of several chronic diseases including non-insulin dependent diabetes mellitus (NIDDM) and coronary heart disease (CHD). Leptin levels in humans have been found to be highly correlated with total adiposity. We performed statistic analysis in order to identify linkage between leptin levels and anthropometric parameters in a group of 285 Czech obese children (152 girls and 133 boys) aged 7 to 18 years. The children were measured using the standard anthropometric technique according to Martin and Saller [16] at the beginning and end of a five-week therapeutic weight reduction programme. The skin fold thickness at 14 sites was assessed by means of Best calliper. The body composition was evaluated using Matiegka's technique. The leptin levels were investigated on the beginning and end of the reduction programme by direct enzyme linked immunosorbent assay (ELISA). For the evaluation of the grade of obesity, body weight, BMI (body mass index), RI (Rohrer's index), FMI (fat mass index) and normalized body weight, normalized BMI and RI were plotted. Correlation analysis shows relation between leptin concentration and FMI to be the most significant. As to ponderal indexes, normalized RI shows the most significant positive correlation. Leptin concentrations are negatively correlated with the proportion of the weight of skeletal muscles by Matiegka both in girls and boys. Intersexual differences in correlations between leptin concentrations and normalized circumferences are observed, as well as in correlations between leptin and particular skin fold thickness. We also tested relations between the magnitude of leptin decreases and magnitude of decreases of anthropometric parameters. There is a strong endorsement both in girls and boys of positive correlation between decrease of leptin concentration and fat reduction. Interestingly, differences between boys and girls in relations between leptin decrease and change in lean body mass had been observed.

Adolescent↗
PubMed2001

Proposed standard definition for child overweight and obesity.

The prevalence of obesity in child population is becoming a serious problem in all advanced countries. Therefore many authors try to find a definition according to which it would be possible to assess overweight and obesity in examined subjects in a simple manner. The simplest way is to plot the subject's data in a percentile zone of reference data according to his BMI value. The problem is dealt with e.g. by Cole et al. (1) who defined internationally acceptable standards of BMI for children and adolescents from 0-18 years. These standards are, however, based only on six national studies and on the assumption that in the population of 18-year-olds there are 10% subjects with BMI values above 25 and 3% subjects with values above 30. The suggested standards thus raise the level of the 90th and 97th percentile, as compared with BMI reference data of 1991 which are used in the Czech Republic. Therefore the ratio of obese children in the Czech Republic and in many other countries would be very small. Internationally acceptable standards should be therefore based on a broader discussion of the professional public.

Adolescent↗
PubMed2000

Growth and development of school children.

With the support of the Internal Grant Agency of the Ministry of Health of the Czech Republic in 1997-1999 work proceeded on the grant "Semi-longitudinal study of the somatic growth of school children in the Czech Republic". The objective of this project is to assess the growth rate of the basic bodily characteristics in children and youth aged 6 to 14 years, to confirm the positive secular trend in height and body weight or its slowing or stagnation, and also to evaluate the growth and development of children under the new socio-economic conditions. In addition to thirty somatic characteristics which are assessed repeatedly every six months, in 1,925 children some supplementary data were obtained from parents. From hitherto assembled data ensues that there was no significant change of the mean length at birth nor of the birth weight as compared with 1989. The increase in height up to adolescence continues, in the higher age groups probably stagnation occurs. Despite a slight increase of mean body weight values since 1981, a gradual decline of the BMI values was observed. In boys this tendency is less marked than in girls, in particular in the oldest age groups. This trend was confirmed also by the results of the present investigation. As compared with the results of the 5th Nationwide Anthropological Survey in 1991 the group of overweight children, i.e. those above the 90th percentile of BMI comprises 6.9% boys and 8.9% girls from a total of almost 2,000 children, as compared with the expected 10%.

Adolescent↗
PubMed2000

Influence of positioning of infants on long-term changes of cephalic dimensions.

The submitted investigation describes long-term changes of 3 main cephalic dimensions (head circumference, maximal length and maximal width of the head) and analyses the possible influence of positioning of infants after birth (prone, supine and side sleeping position) on these changes. Information about children aged 6 months to 3.99 years, where the need of up-to-date data is greatest, were collected as part of an extensive anthropological survey implemented in 1995 to 1997 in the entire Czech Republic. The authors confirmed the trend of debrachycephalization, which is manifested by a statistically significant increase of the maximal length of the head and a statistically significant decrease of the maximal width of the head, as compared with children examined in the anthropological survey in 1956 to 1962 (1). These changes were established in the group of boys (200 boys) as well as in the group of girls (167 girls). The differences of the magnitude of long-term changes between boys and girls were not significant. Evaluation of the long-term changes of the head circumference in the entire group of 366 children aged 0.5-3.99 years (the head circumference of one girl was not measured) revealed a statistically significant increase of this dimension. During the period from 1956/62 till 1996, the influence of positioning on the magnitude of long-term changes of head circumference was not proved. We can say the same about the maximal length of the head of boys and girls and about the maximal width of the head of girls. Only between three differently positioned groups of boys (prone, side, supine) statistically significant differences in the magnitude of long-term changes of the maximal width of the head were found (p < 0.05). Highly significant changes of the maximum width and maximum length of the head occurred as compared with a reference group in all three groups of positioning of infants and in both sexes. The trend of debrachycephalization seems to be thus a more potent factor, which affects long-term changes in the shape of the head, then the predominating sleeping position during the first months after birth. This conclusion is supported by the persisting trend of debrachycephalization, although the supine position is now preferred.

Analysis of Variance↗
PubMed1998

[Anthropologic methods in the evaluation of the weight reduction process in obese children].

Childhood obesity is considered at present one of the most difficult problems in paediatrics and it is one of the major health problems of industrialized society. Growth and development of obese children is different in several aspects. The authors submit the results of an anthropometric survey implemented in 1989 to 1996 in a group of 1949 Czech obese children (720 boys and 1229 girls) aged 6 to 18 years. The patients were measured by the standard anthropometric technique according to Matrin and Saller at the beginning and end of six-week therapeutic weight reduction programme. The skinfold thickness at 14 sites was assessed by means of a Best caliper. The body composition was evaluated using Matiegka's equations. For evaluation of the weight reduction programme the paired t-test was used a criterium of the quality of the evaluated parameters. For the needs of the medical profession curves of the empirical percentiles of BMI for both sexes were plotted to evaluate the grade of obesity. From the analysis of anthropometric data using the paired t-test in 1949 probands ensues that the most valuable information as regards circumferential measurements in boys is provided by the circumference of the abdomen, the gluteal area followed by the chest circumference. In girls the results are partly different--a gluteal circumference of thigh highly dominates, gluteal circumference follows, chest circumference mesoeternal is the third. As to skinfolds the authors recommended to monitor in boys the supraileac, subscapular and abdominal skinfold. In girls the following order was assessed: supraileac, thoracic (at the level of the 10th rib) and subscapular skinfold. From the accurate assessment of the body composition of obese children subjected to weight reduction ensues our recommendation that the loss of adipose tissue should be at least seven times greater than the loss of musculature. A lower ratio should be an indication for changing the reducing treatment. Methods of direct anthropometry, incl. calipering can be unequivocally recommended as the method of first choice because of their non-invasive character.

Adolescent↗
PubMed1994

Vth nation-wide anthropological survey 1991 in the Czech Republic comparison with 1981 data.

The objective of the survey was to assess whether a secular trend still affected growth of the Czech child population and, if necessary, to update national growth standards. The study was designed in such a manner so that trends in child growth, obtained from comparisons of body height, body weight and head circumference from the two successive nation-wide representative surveys (1981, 1991) of the Czech child population, could be followed. Representative random samples of the Czech child population from 0 to 18 years of age were studied with the following number of examined subjects: 86,846 in 1991 and 117,643 in 1981. Nation-wide standards and growth charts for assessment of growth and development of both individuals and specific groups present main outcome of the survey. Statistically significant differences were found in body height (both sexes) and weight (more in boys). No highly significant differences were registered in head circumference. Based on newly assembled data growth charts for assessment of body height, proportionality and head circumference were designed. The findings of this study did not support the hypothesis that the secular trend in Czech child population has already ceased.

Adolescent↗
PubMed1993

[The 5th nation-wide anthropological study of children and adolescents held in 1991 (Czech Republic)--selected anthropometric characteristics].

The Vth nation-wide survey of children and adolescents which was conducted in autumn 1991 under new conditions comprised again, similarly as the four previous ones, a representative sample selected by random sampling. As compared with the 1981 survey, the anthropometric parameters were extended by the circumference of the relaxed left arm and the hip circumference. A questionnaire for parents was elaborated where by a quite new approach was used. The still positive action of the secular trend of increasing height was confirmed. The action of the trend shifts to younger age groups, as compared with former surveys. The present survey confirmed also a tendency towards slimness in both sexes, however, in particular in girls a shift of this tendency to younger age groups was apparent. It will be certainly necessary to evaluate in future whether this trend reflects also a more favourable ratio of body composition. With regard to these changes the authors submit new percentile charts for evaluation of height, proportionality, and for children under three years, also head circumference.

Adolescent↗
PubMed1991

Chest diameters in the body mass forecast.

Two other body mass indices have been studied in the paper, by means of which the density is to measure human body has on the surface and in the volume of the hypothetic cylinder with the height equal to that of stature and with the circumference computed from the transverse and sagittal diameters of the chest. Thus we have to do with a modification of the procedure where the width and depth of chest were given by its circumference (mesosternale). The reason which made this modification interesting for us was in that the measurement of the transverse and sagittal diameter of the chest did not depend--when compared with the chest circumference measurement--so much on the muscular and fat tissue of the human body. Both these body mass indices have been used also to forecast body mass adequate to the respective skeletal space--surface and volume of the cylinder constructed by means of the dimensions of the skeleton: stature and transverse and sagittal diameter of the chest. Prediction efficiency of both these formulas has been verified numerically by means of an extensive data material of the Czechoslovak Spartakiade 1985, in dependence on sex and age. Information contribution of the chest diameters in the adequate body mass forecast proved to be doubtless. Besides it the possibility has been discussed to increase prediction reliability of body mass by combining both procedures under consideration with respect to the values of skeletal dimensions of the respective proband.

Adolescent↗
PubMed1990

[Selected anthropometric findings in women with disorders of glucose tolerance with hypertension].

In a group of 26 women with an impaired glucose tolerance anthropometric measurements of basic somatometric characteristics were made with special attention to the subcutaneous fat distribution and compared the findings with the healthy Czech population. Changes in body build, BMI, subcutaneous body fat distribution were evaluated and the causality of the relationship between blood pressure and gluteofemoral and abdominal obesity was investigated. From the author's observations ensues that in the group of women with impaired glucose tolerance overweight was recorded, as compared with the normal population, disproportions in the circumferences of the trunk and extremities, an excessive percentage of body fat, well developed muscles. In abdominal obesity a significant increase of the blood pressure and BMI was found.

Adult↗
PubMed1989

[Problems in evaluating obesity in childhood].

For screening of obese children and marginal obesities the authors elaborated tables for boys and girls aged 6 to 18 years. The tables are based on height and body weight of the Czechoslovak population examined in 1985.

Adolescent↗