Birth body length, birth body weight and birth head circumference in neonates born in a single centre between 2011 and 2016

   Objectives: Access to updated and accurate standards for local populations is important for the interpretation of body measurements in neonates and may have an impact on the doctor’s recommendations for monitoring early childhood development. Study aim: to present individual mean values for the most prevalent body measurements (i.e. birth body length (BBL), birth body weight (BBW) and birth head circumference (BHC)) in neonates and compare them to the duration of pregnancy. Material and methods: The measurements (BBL, BBW and BHC) were collected and analyzed from over 27,000 neonates born in a single center. All women with single pregnancies with gestation ranging from 33 to 42 weeks were included in the study. Results: Mean values and statistically significant standard deviation values from population standards of BBL, BBW, and BHC were evaluated for neonates that were born between the 33rd and 42nd week of gestation. Analysis was conducted for the lower limit (10th percentile), average (50th percentile) and upper limit (90th percentile). Conclusions: This was the first time in Polish literature when population standards were presented for three body meas­urements of neonates. With the size of the cohort, these standards can be successfully implemented into routine clinical practice, especially for screening children with body size deficits.

Changes in thrust force in swimmers in the annual training cycle

Study aim: Determination of changes in thrust force and effect size of training load in swimmers using four swimming strokes monitored 4 times a year

Body mass index – proposed norms for children and youths

The aim of the study was to establish normal BMI values vs. age for children and youths having normal body fat content and to confront them with Cole’s cut-off points. In cohorts of 1373 boys and 1805 girls, aged 7–20 years, body fat content was determined from 3 skinfolds (triceps, subscapular, abdominal) using Slaughter’s equations. Next, 1069 boys and 759 girls with acceptable fat percentage (NF groups) were selected and for them log BMI values were computed. Equations of log BMI vs. age (means and SD) computed for NF groups served to present the proposed BMI norms. The obtained upper limits (mean log + 2SD) for boys and girls aged 19 years were 24.6 and 24.5, respectively, and the corresponding body fat contents –23.7 and 24.1, respectively. Inasmuch BMI does not reflect the real body fat content, the presented norms, based on acceptable body fat content, seem to reflect the weight-height relations better than those derived from unselected population data.POST-PUBLICATION NOTICESThe study was partly supported by grants No. AWF-DS.153 of the Polish Ministry of Science and Higher Education. Please note that the order of the authors of this paper should be:  Tomaszewski, Stupnicki, Milde, not  Stupnicki, Tomaszewski, MildePlease note that the e-mail address of the corresponding author is [email protected], not [email protected]

Waist-to-height ratio (WtHR): proposed approach to establishing reference values for children and youths

Detection of central obesity is usually based on the criterion represented by the waist-to-height ratio (WtHR)≥ 0.50. However, that criterion has been disputed, especially in the period of growth. Since obesity cannot be reasonably defined without involving body fat content (%F), the aim of the study was to establish gender- and age-specific reference WtHR values for children and youths selected for an acceptable %F. In cohorts of 1193 boys and 1307 girls, aged 7–20 years, body fat content was determined from 3 skinfolds (triceps, subscapular, abdominal) using Slaughter’s equations. Next, 505 boys and 396 girls with acceptable fat percentage were selected and for them log WtHR values were computed. The equations for log WtHR values vs. age (a) were: (–0.31–0.01264a+0.000476a2)±0.0283 for boys and (–0.268–0.02047a+0 .00073a2)±0.0344 for girls. Upper WtHR limits (means +2SD) attained minimum values (0.460 and 0.454) in the age range of 12–15 years. When applying that criterion to subjects with excessive %F, 14.3% of all boys and 18.2% of girls were classified as centrally obese, but only 8.5 and 9.3%, respectively, when the WtHR=0.50 criterion alone was used. Cut-off values for WtHR indicating central obesity are markedly lower than 0.50 especially in the adolescence period and can be applied only to subjects with excessive fat percentage. POST-PUBLICATION NOTICESThe study was partly supported by grants No. AWF-DS.153 and AWF-DM.10 of the Polish Ministry of Science and Higher Education.Please note that the e-mail address of the corresponding author is [email protected], not [email protected]