Ignacio Felipe Bejarano

The LMS method and weight and height centiles in Jujuy (Argentina) children.

Human growth and its resulting patterns display a great inter- and intra-population heterogeneity that reflects the quality of life, health and nutritional condition of populations. The aim of this work was to expand the knowledge about the growth of Jujenean children by statistical procedures that graphically express the relation of anthropometric variables to age and allow their comparison with specific references. Anthropometric data came from 9092 children (0-5 years) from various localities of Jujuy province (northwest Argentina) located at 1200 m above sea level (ma.s.l.). The centiles of weight for age (W/A) and height for age (H/A) were obtained by the LMS method using maximum penalized likelihood. A statistical and graphic comparison was made with the corresponding Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) centile references. In general, estimated centiles were lower than those in both references. Discrepancies for H/A in comparison with the CDC reference ranged between 1.09+/-0.59% and 1.66+/-0.34%, and for W/A between 1.82+/-1.56% and 3.36+/-1.4%. In comparison with the WHO reference, discrepancies ranged from 1.38+/-0.65% to 1.87+/-0.41% for H/A, and from 1.12+/-1.28% to 2.74+/-1.49% for W/A. Centile discrepancies were attributed to the characteristics of early childhood feeding and the interaction of a set of biological and mesological factors that the Jujenean population is exposed to. Growth and nutritional conditions of this population should be evaluated with the WHO reference, for it reflects the recent growth pattern of biologically and culturally healthy children raised in favourable conditions, a pattern that also reflects that of Jujenean children.

Geographic altitude, surnames, and height variation of Jujuy (Argentina) conscripts

The height records of 48,589 conscripts born in Jujuy between 1870 and 1960 were examined in order to study the variation in adult male height (AMH) in terms of geographical altitude and surnames. Data were clustered by origin of surnames (divided into native and foreign names), decades, and according to the four Jujenean geographical regions distributed along an altitudinal gradient (Puna, Quebrada, Valle, and Ramal). The variation of surnames, geographical altitude, and time on human height were examined by analysis of variance. Regardless of the drafting year, individuals in the four regions bearing foreign surnames proved significantly taller (P < 0.001) than those who had a native surname. Average height, regardless of ethnic group, presented a reverse relationship to geographical altitude. A higher AMH was found in individuals bearing foreign surnames in Jujuy and lower ones in the population located in the highlands and bearing native surnames. Interregional and intergroup AMH variations would be affected by the complex interaction between geographical altitude and factors associated to it and by the ethnic characteristics of these population as well.

Weight and height percentiles calculated by the LMS method in Argentinean schoolchildren. A comparative references study

Abstract Background: The Argentinean population is characterized by ethnic, cultural and socio-economic diversity. Aim: To calculate the percentiles of weight-for-age (W/A) and height-for-age (H/A) of schoolchildren from Argentina employing the LMS method; and to compare the obtained percentiles with those of the international and national references. Subjects and methods: Anthropometric data of 18 698 students (8672 girls and 10 026 boys) of 3–13 years old were collected (2003–2008) from Buenos Aires, Catamarca, Chubut, Jujuy, La Pampa and Mendoza. Percentiles of W/A and H/A were obtained with the LMS method. Statistical and graphical comparisons were established with the WHO (international reference) and with that published by the Argentinean Paediatric Society (national reference). Results: Differences in W/A and H/A, regarding the references, were negative and greater at the highest percentiles and in most of the age groups. On average, the differences were greater for boys than girls and for national than international references. Conclusion: The distribution of weight and height of schoolchildren, coming from most regions of the country, differs from those of national and international references. It should be advisable to establish a new national reference based on internationally recognized methodological criteria that adequately reflect the biological and cultural diversity of the Argentinean populations.

Geographical altitude, size, mass and body surface area in children (1-4 years) in the Province of Jujuy (Argentina).

Abstract Background: Highland child populations show low growth rates. Aim: To evaluate the variation of size, mass and body surface area of Jujenean infants (1–4 years) as a function of geographic altitude. Subjects and methods: Nutritional status of 8059 healthy infants was determined based on weight and height data; body mass index, ponderal index, body surface area, body surface area/mass and ectomorphy were calculated. Variables were standardized with a provincial mean and WHO references. Data were grouped by age, sex and geographic altitude: Highlands (≥2500 masl) and Lowlands (<2500 masl). Chi-square, correlation and t-tests were applied. Results: Highlands infants had higher prevalence of stunting, reduced height, weight, body surface area and ectomorphy; also higher body mass index, ponderal index and body surface area/mass. The population average z-score for height, weight and body surface area was positive in Lowlands and negative in Highlands. The opposite happened with body mass index, ponderal index and body surface area/mass. In Highlands and Lowlands the average z-score reference was negative for weight and height and positive for body mass index. Correlations between indices were high and significant, higher in Highlands. Conclusion: Jujenean children differ in size, mass and body surface area based on the geographical altitude and adverse nutritional and socioeconomic factors.

Development of subcutaneous fat in Spanish and Latin American children and adolescents: Reference values for biceps, triceps, subscapular and suprailiac skinfolds

Subcutaneous fat skinfolds represent a reliable assessment instrument of adiposity status. This study provides current percentile references for four subcutaneous skinfolds (biceps, triceps, subscapular, suprailiac) applicable to children and adolescents in Spain and in Latin American countries where data are scarce. The design consisted of a cross-sectional multicenter study performed with identical methods in 5 countries (Argentina, Cuba, Mexico, Spain and Venezuela). Total sample comprised 9163 children and youths (boys 4615 - girls 4548) aged 6-18 years, healthy and without apparent pathologies. Percentiles 3, 5, 10, 25, 50, 75, 90, 95 and 97 were calculated by the LMS method. Sexual dimorphism was assessed using the t-test and age differences with ANOVA. Normalized growth percentile references were obtained according to sex and age for each skinfold. The mean values of four skinfolds were significantly greater in girls than boys (p<0.001) and, in both sexes, all skinfolds show statistical differences through age (p<0.001) with different magnitudes. Except triceps in girls, peaks between 11 and 12 years of age are more noticeable in boys than in girls. Although the general model of growth is known, the skinfold measurements show variability among populations and differences of magnitude are presented according to the analyzed population. Therefore, these age and sex-specific reference percentile values for biceps, triceps, subscapular and suprailiac skinfolds, derived from a large sample of Spanish and Latin American children and adolescents, are a useful tool for adiposity diagnosis in this population for which no reference values were available.

SUBSCAPULAR AND TRICEPS SKINFOLDS REFERENCE VALUES OF HISPANIC AMERICAN CHILDREN AND ADOLESCENTS AND THEIR COMPARISON WITH THE REFERENCE OF CENTERS FOR DISEASE CONTROL AND PREVENTION (CDC).

INTRODUCTION the assessment of the skinfold thickness is an objective measure of adiposity. Therefore, it is a useful tool for nutritional diagnosis and prevention of metabolic risk associated with excess fat in chilhood and adolescence. OBJECTIVE to provide percentiles of subscapular and triceps skinfolds for Hispanic American schoolchildren and compare them with those published by the Centers for Disease Control and Prevention (CDC) from United States, that it have been commonly used as a reference in most of these countries. METHODS subscapular and triceps skinfolds were measured in 9.973 schoolchildren 4-19 aged from Spain, Argentina, Cuba, Venezuela and Mexico with Holtain caliper with 0.2 mm accuracy. Percentiles were obtained with the LMS statistical method and were presented in tables divided in stages of 6 months and in curves graphics. The difference between Hispanic American and CDC mean values were provided for P3, P50 and P97 in mm and also were graphically represented. RESULTS skinfolds measurements obviously increased with age in both sexes but, in boys, this increase is much more marked in highest percentiles between 8 and 13 years; this maximum is reached earlier than what occurs in CDC reference. In both sexes, all percentiles analized in Hispanic American schoolchildren were higher than the CDC reference except P97 up to 10 or 13 years that was notably smaller. CONCLUSIONS the skinfolds percentiles of Hispanic American children and adolescents differ from CDC that are usually used as reference. The values of subscapular and triceps skinfolds provided in this study, could be applied to populations of a similar ethnic background, especially in comparative studies of body composition.