Feminization of the fat distribution pattern of children and adolescents in a recent German population

Comparison of frame index reference percentiles in Argentine and European boys and girls

INTRODUCTION

The frame index (FI), based on measurements of elbow breadth and height, is the body frame size parameter most frequently used in child and adolescent populations to assess skeletal robustness. In 2018, the first FI reference percentiles were elaborated with data of boys and girls aged 0-18 years from different European populations. In Argentina, the FI reference values were published in 2022.

OBJECTIVE

The present study aims to compare the Argentine (AR) and European (EU) FI reference percentiles to evaluate possible variation in bone robustness between populations.

METHODS

The values of the 3rd, 50th and 97th percentiles of the AR and EU FI references for boys and girls aged 4-14 years were compared using the Wilcoxon test (p < .05). Percentage differences between means (PDM) were calculated to analyze the magnitude of the differences between both references. The R 3.2.0 program was used to plot the percentile curves.

RESULTS

The FI reference values were lower in AR than in EU in both the 3rd and the 50th percentiles, regardless of sex and age. Conversely, the AR reference values of the 97th percentile were higher than the EU values at most ages.

CONCLUSIONS

The comparison of the AR and EU FI references showed similar age and sex growth patterns. However, differences in percentile values between populations were observed, highlighting the importance of having local references for the evaluation of skeletal robustness.

Bergmann's rule is a "just-so" story of human body size

Carl Bergmann was an astute naturalist and physiologist. His ideas about animal size and shape were important advances in the pre-Darwinian nineteenth century. Bergmann's rule claims that that in cold climates, large body mass increases the ratio of volume-to-surface area and provides for maximum metabolic heat retention in mammals and birds. Conversely, in warmer temperatures, smaller body mass increases surface area relative to volume and allows for greater heat loss. For humans, we now know that body size and shape are regulated more by social-economic-political-emotional (SEPE) factors as well as nutrition-infection interactions. Temperature has virtually no effect. Bergmann's rule is a "just-so" story and should be relegated to teaching and scholarship about the history of science. That "rule" is no longer acceptable science and has nothing to tell us about physiological anthropology.

Changes in adiposity and fat tissue distribution among preschool children from Kraków, Poland, from 2008 to 2018

In the light of changes in the living conditions of populations, excess adiposity is currently a serious public health problem worldwide. The aim of this study was to assess the changes in the body fat ratio among preschool children aged 3–7 years from Kraków, Poland, between 2008 and 2018. The study group consisted of children examined in two cross-sectional studies. Analysed characteristics included triceps, calf, subscapular, abdominal and suprailiac skinfold thicknesses, and adiposity calculated according to Slaughter’s equations. The trunk adiposity index and limbs-to-trunk fat ratio were also calculated. Statistical significance was obtained using two-way ANOVA and Tukey’s tests. Lower-limb adiposity was largest in the 2008 cohort and trunk adiposity was greater in the 2018 cohort. The mean values of the trunk adiposity index and limbs-to-trunk fat ratio were lower in the 2018 cohort than in the 2008 cohort. The 2018 cohort was also characterized by a lower overall adiposity. Regardless of the lower body adiposity percentage, in 2018 there was a tendency towards the central allocation of fat tissue. This is a negative phenomenon because, especially when co-existing with reduced lower-limb adiposity, it is associated with an increased risk of metabolic and cardiovascular diseases, even in young children.