Lambda , Mu And Sigma Research Articles

Benchmarking the Determinants of Nutritional Status among Community Schools’ Children in Nepal

The government of Nepal initiated the Mid Day Meal Program (MDMP) to reduce hunger and increase educational outcomes, including health status. However, limited studies have been conducted on these issues covering the nutritional status of students at the lower basic level at community schools in Nepal. The main objective of the study is to determine the factors associated with malnutrition among children from community schools in Nepal. A school-based cross-sectional study was conducted in 98 (46 basic and 52 secondary) community schools from 44 municipalities in Nepal. Altogether, 2727 students participated in the questionnaire survey and anthropometric measurement. Data collection was performed on May 10-31, 2023. WHO Anthro plus and LMS (Lambda Mu and Sigma) parameters were used: weight for age for national health and nutrition survey recommended by CDC/National Center for Health Statistics for ages older than ten years to analyze nutritional status, including z scores. Descriptive analysis, including inferential analyses such as the chi-square test and logistic regression, was performed using IBM SPSS Statistics v25. The prevalence of weight-for-age Z-score[WAZ], height-for-age Z-score [HAZ], and body mass index-for-age Z-score [BAZ] were 72%, 75%, and 82%, respectively. Students with z-scores outside the range of ±2 were classified as malnourished. Of them, 27.3%, 23% and 16.6% were assessed as underweight, stunted and thin, respectively. Students' sociodemographic characteristics such as age, asex, family size and type, source of income, wealth status were significantly associated with malnutrition, while age group, gender, wealth status, residence setting, and geographical location were noted as significant predictors of nutritional status. The study found no statistical relationship between school feeding and good nutrition, questioning the quality of the midday meal program. The study concludes that existing school-based nutritional interventions need to be re-evaluated and re-designed since it is less potent to minimize malnutrition among students substantially. Policymakers could consider these findings when planning and implementing nutrition-related policies and programs.

Italian neonatal birthweight charts derived from INeS not separated by birth order

BackgroundIdentifying high-risk neonates with abnormal fetal growth is crucial for health risk prediction and early intervention. Small for gestational age (SGA) and large for gestational age (LGA) classifications highlight neonates having a higher risk for postnatal diseases. Accurate diagnosis depends on precise anthropometric measurements and appropriate reference data. In 2010, specific neonatal charts for Italian singletons (INeS charts) were published, tracing separately for first- and later-born neonates due to a 3% birth weight difference. We present INeS charts for birth weight non-separated by first- and later-born babies useful when information on parity is unavailable or unreliable, or for better comparisons with other neonatal charts that are not separated by birth-order.MethodsINeS charts were traced using a parametric function. Starting with the parameters estimates published in a different paper, INeS charts not separated by birth order were traced for the gestational age range of 23 to 42 weeks. In a second step the charts were parametrized as Cole and Green Lambda Mu and Sigma (LMS) model, allowing computation of standard deviation scores.ResultsThe centiles of non-separated INeS charts follow between first- and later-born charts. Distances varied due to changing first-born proportions with gestational age, Max differences of about 100g with later born and 70g with first-born were observed at term. S and L functions have a similar shape for boys and girls. S function shows a pick at about 29 weeks, L function has positive values in all the range of gestational age with a pick at 39 weeks.ConclusionsThe study presents non-separated Birth Weight INeS charts, bridging the gap when parity information is unavailable. Differences with separated charts were generally small, making them reliable for neonatal health assessment. Insights from L and S parameters contribute to standardized birth weight and adjust it by sex and Gestational Age, useful for defining SGA or LGA neonates. The paper enhances neonatal care tools, showcasing INeS chart flexibility in different clinical scenarios and supporting neonatology research.

Normative reference and cut-offs values of maximal aerobic speed-20 m shuttle run test and maximal oxygen uptake for Tunisian adolescent (elite) soccer players

This study aimed to develop reference curves of aerobic parameters of 20 m shuttle run test for Tunisian soccer players. The study was conducted in the 2022/2023 pre-season. The reference curves of the maximal aerobic speed (MAS) and the maximal oxygen uptake (VO2max) were developed according to the Lambda, Mu and Sigma (LMS) method, using data from 742 Tunisian premier league soccer players aged 11–18 years. Measured variables included: weight, height, body mass index and maximal heart rate (HRmax). HRmax was measured when the participants completed the maximal aerobic speed. VO2max was estimated using the 20 m shuttle run test protocol (speed increment every minute). Our results presented the smoothed percentiles (3rd, 10th, 25th, 50th, 75th, 90th and 97th) of MAS (km/h) and VO2max (ml/kg•min⁻1) according to age. In addition, raw data showed that VO2 max was positively correlated with age (r = 0.333; P < 0.001), height (cm) (r = 0.279; P < 0.001), weight (kg) (r = 0.266; P < 0.001), practice period (years) (r = 0.324; P < 0.001) and BMI (kg/m2) (r = 0.10; P < 0.05). However, it was negatively correlated to HRmax (bpm) (r = −0.247; P < 0.001). Only the measurements within the age group [12–12.99] are significantly higher (p < 0.001; ES = 0.63) compared with the previous age group [11–11.99]. Finally, regarding prevalence, our findings showed that 15.5 % of the players in our sample had VO2max values above the 87.7th percentile cut-off, while only 0.3 % exceeded the 99.18th percentile. The development of normative curves could help coaches and physical trainers to more accurately detect weaknesses in the aerobic performance of their players in order to sustain high-intensity repetitive actions during a soccer match.

INDICATORS OF ABDOMINAL OBESITY: WAIST CIRCUMFERENCE AND WAIST-TO-HIP RATIO IN ADOLESCENTS OF NORTH MACEDONIA

Obesity in children and adolescents in the world is reaching a scale of an epidemic. It is considered the most widespread disease in children in many countries, especially in developed countries. The aim of this study was to define WC and WHR among Macedonian adolescents aged 11 to 14 years. A cross-sectional study was performed in 2013-2015, comprising a sample of 1267 adolescents of the Republic of Macedonia aged 11 to 14 years; 646 males and 621 females. Weight, height, body mass index (BMI), waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR) were measured and percentiles were calculated using Cole’s Lambda, Mu and Sigma (LMS) method. The relation between WHR and general obesity, as defined by the International Obesity Task Force, was investigated with receiver operating characteristic (ROC) analysis.&nbsp;The boys had statistically significant higher values ​​in all anthropometric measures, except in HC where statistically significant gender differences were not found. BMI, WC, and HC increased with the age. The obtained reference percentile curves can be used temporarily for obesity screening in children and adolescents. Keywords: abdominal obesity; adolescents, anthropometric measurements.

Foot characteristics during walking in 6\u201314- year-old children

The main purpose of the study was to establish foot characteristics during walking in children. In this cross-sectional study, we recruited 1 284 primary-school students aged 6–14 years (714 boys and 570 girls) randomly selected from five schools in the city of Brno, Czech Republic. Children walked across a pressure platform (EMED-xl; NovelGmbH, Munich, Germany) to collect the data for both left and right foot during three trials. After the procedure, the software generated several foot characteristic variables: (1) force-time integral, (2) pressure-time integral, (3) contact area, (4) contact time, (5) peak pressure and (6) average pressure for the total foot. Curves for the 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles were calculated using the Lambda, Mu and Sigma (LMS) Chartmaker software. Our results showed that boys had longer force-time integral, higher contact area and contact time values, and higher peak plantar pressure, while no significant differences in pressure-time integral and average plantar pressure between sexes were observed. Older boys and girls had higher values in all measured variables. Our results provide for the first-time sex- and age-specific foot characteristics during walking in 6–14-year-old children.

Waist circumference, waist-to-hip ratio, and waist-to-height ratio reference percentiles for abdominal obesity among Macedonian adolescents.

Background: the goal of this study was to define waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHRt) smoothed reference percentiles for assessing abdominal obesity in Macedonian adolescents aged 11 to 18 years in order to investigate possible obesity cut-offs of WHR and WHtR, and to compare WC percentiles with those of other adolescents. Methods: the research was conducted on a sample of 2,490 adolescents of the Republic of Macedonia aged 11 to 18 years: 1,288 males and 1,202 females. Weight, height, body mass index (BMI), WC, hip circumference (HC), WHR and WHtR were measured and percentiles were calculated using Cole's Lambda, Mu and Sigma (LMS) method. The relation between WHR, WHtR and general obesity, as defined by the International Obesity Task Force, was investigated with a receiver operating characteristic (ROC) analysis. Results: the boys had statistically significant higher values in all anthropometric measures except in HC, where statistically significant gender differences were not found. BMI, WC, and HC showed an increasing trend with age. The WHtR variable is a better indicator for assessing general obesity in both boys and girls (AUC, 95 % CI: 0.905-0.928) than WHR, which showed lower AUC values (95 % CI: 0.697-0.734) in predicting IOTF obesity; the WHtR cut-off of 0.5 had a sensitivity of 74 % and a specificity of 92 % for both genders and all age groups. Conclusions: the obtained reference percentile curves can be used temporarily for early detection of abdominal obesity among Macedonian adolescents aged 11 to 18 years; a WHtR of 0.5 may also be used as an obesity threshold in these age groups.

Normative values for relative schoolbag weight in primary school children aged 6-14 from Czech Republic: A pilot study.

Little evidence from observational studies has been provided regarding ‘optimal’ relative schoolbag load during primary education. Also, no study to date has provided reference-based standards for relative schoolbag weight. Therefore, the main purpose of the study was to establish normative values of relative schoolbag weight in a sample of children. In this cross-sectional study, we recruited 584 primary school students aged 6–14 (meanage±SD = 9.6±2.4 yrs, meanheight±SD = 1.4±0.2 m, meanweight±SD = 37.5±13.3 kg, meanbody-mass index±SD = 17.6±3.1 kg/m2, 44.4% girls) chosen from five schools in the city of Brno. Schoolbag weight and child’s body weight were objectively measured by using digital scale. Relative schoolbag weight was calculated by dividing schoolbag weight with child’s body weight and the result was expressed in percentage. Lambda, Mu and Sigma (LMS) method was used to create sex- and age-percentile curves. Boys carried slightly heavier schoolbag, compared with girls (mean difference 0.2 kg, p = 0.020). No significant differences between sexes in relative schoolbag weight were observed (p = 0.240). Median values (P50) for boys and girls were similar and the largest observed between ages 6–9 in boys (15–17%) and 6–8 in girls (16–18%). The percentage of children carrying relative schoolbag weight beyond 10% of their body weight was very high, especially between ages 6–10 in boys (85.1–100%) and 6–11 in girls (86.8–95.4%). This study provides first sex- and age- relative schoolbag weight normative values in primary school children. Future studies should use similar methods for generating comparable data.

The preliminary development of reference values of carotid artery intima-media thickness in children aged 6-11 years

Objective: To develop the reference values of carotid intima-media thickness (cIMT) in Chinese children aged 6-11 years. Methods: A convenient cluster sampling method was used to conduct a cross-sectional survey from November 2017 to January 2018 in a primary school in Huantai County, Zibo City, Shandong Province. A total of 1 033 children aged 6-11 years (excluding children with obesity or hypertension) were included. Percentile curves for cIMT were drawn using the lambda, mu and sigma (LMS) method. Results: This study developed the cIMT reference values (P(90) and P(95)) for sex and age aged 6-11 years, including P(90) and P(95) reference values of mean cIMT, left cIMT and right cIMT, respectively. With the increase of age, the cIMT percentile values also increased. For the same age and the same percentile, the cIMT values of boys were higher than those of girls. Conclusion: This study developed sex-specific and age-specific cIMT percentile reference values in children aged 6-11 years.

Differences in Cardiorespiratory Fitness between Chinese and Japanese Children and Adolescents.

Background: This study aimed to compare the difference in cardiorespiratory fitness between Chinese and Japanese children and adolescents. Methods: Participants comprised 9025 children and adolescents aged 7–18 years from China and Japan. Cardiorespiratory fitness (CRF) was measured by performance in the 20 m shuttle run test (20mSRT) and estimated maximal oxygen consumption (VO2max). Differences in CRF between countries were evaluated by t-tests. Centile curves for the 20mSRT and VO2max values were constructed for Chinese and Japanese children and adolescents, respectively, using the Lambda Mu and Sigma (LMS) method. Results: (1) For most of the age groups, the 20mSRT and VO2max performances among Chinese participants were lower than among Japanese participants. (2) Japanese children had the most apparent gains in P10, P50, and P90 VO2max values in primary school; however, they gradually decreased in middle school. For Chinese girls, the P10, P50, and P90 VO2max values decreased gradually with age. (3) The VO2max value among Japanese children increased; however, it decreased or remained flat among Chinese children in primary school. Conclusions: CRF among Chinese participants was lower than among Japanese participants while the VO2max value showed different trends in primary school. Effective measures should be taken to improve CRF among children and adolescents.

Assessing health impacts of home food gardens with Wind River Indian Reservation families: protocol for a randomised controlled trial

IntroductionThis community-based participatory research, Growing Resilience, will be the first full-scale randomised controlled trial we have identified that is designed to evaluate impacts of home gardening on family health. It...

An anthropometric survey of US pre-term and full-term neonates

Background: Anthropometric data prove valuable for screening and monitoring various medical conditions. In young infants, however, only weight, length and head circumference are represented in publicly accessible databases.Aim: To characterise length and circumferential measures in pre-term and full-term infants up to 90 days post-natal.Subjects and methods: In eight US medical centres, trained raters recorded humeral, ulnar, femoral, tibial and fibular lengths along with mid-upper arm, mid-thigh, chest, abdominal and neck circumference. Data were pooled by post-menstrual age into 1-week intervals and population curves created using the lambda, mu and sigma (LMS) method. Goodness-of-fit was assessed by examining de-trended quantile-quantile plots, Q statistics and fitted centiles overlaid on empirical centiles.Results: In total, 2097 infants were enrolled in this study with a mean ± SD gestational age and post-natal age of 37.1 ± 3.3 weeks and 27.3 ± 25.3 days, respectively. A re-scale option was used to describe all curves. The resultant models reliably characterised anthropometric measures from 33–52 weeks PMA, with less certainty at the extremes (27–55 weeks).Conclusion: The population curves generated under this investigation expand existing reference data on a comprehensive set of anthropometric traits in infants through the first 90 days post-natal.

International normative 20 m shuttle run values from 1 142 026 children and youth representing 50 countries

ObjectiveTo develop sex-specific and age-specific international norms for the 20 m shuttle run test (20mSRT) in children and youth (aged 9–17 years), and to estimate the prevalence meeting the FITNESSGRAM...

Trends and physiology of common serum biochemistries in children aged 0–18 years

The aim of this study was to visually present and discuss in detail the physiological trends of 22 serum biochemistries in children aged 0-18.A data-mining, LMS (lambda, mu, and sigma) approach was employed to derive the smoothed continuous serum biochemistry centile charts, after application of stringent outlier exclusion criteria.Serum sodium and calculated osmolality are low in early life and rise with age due to maturing kidney and body water redistribution. Urea, creatinine and uric acid is high at birth, declines to reach a trough by 1 month of age and gradually rises again thereafter. Serum bicarbonate falls initially during the neonatal and toddler period, then rises with declining respiratory rate, further increasing sodium and suppressing chloride. Potassium, calcium and phosphate are required for somatic growth and are actively accrued during periods of rapid growth. Albumin increases until puberty while globulin rises to age 10 as a result of increased hepatic synthetic capacity and maturing immunity. Serum alkaline phosphatase activity peaks during bone growth spurts in infancy and adolescence due to osteoblast leakage, while creatinine increases with muscle mass. Serum gamma-glutamyl transferase, aspartate aminotransferase and lactate dehydrogenase activities are high at birth and decline with age. Serum alanine aminotransferase activity is low at birth and is induced by increased gluconeogenesis. Serum bilirubin increases continuously with age, mirroring haemoglobin concentration. Serum total cholesterol declines more markedly in boys than girls during puberty due to the combined effects of free testosterone (lowering high-density lipoprotein cholesterol in boys) and oestradiol (lowering low-density lipoprotein cholesterol in boys and girls).It is important to understand trends and biological variation when interpreting results since partitioned reference intervals may mask this information.

Measurement of Neck Circumference and Its Correlation with Body Composition in a Sample of Students in São Paulo, Brazil

Purpose: The purpose of this study was to verify the correlation between neck circumference (NC) and body mass index (BMI) in children, and to determine NC percentiles for Brazilian children. Methods: The subjects of this cross-sectional study were students between the ages of 6 and 19 years from five schools in São Paulo, Brazil. Clinical and anthropometric data were collected from the students from April 2011 to June 2012. NC was measured at the level of the cricoid cartilage. We calculated Pearson correlation coefficients between NC and other indices of obesity with Sigma Stat 3.5. NC percentiles were produced using the LMS (lambda, mu, and sigma) method (STATA 12.0). Results: Among 2,794 students, 49.9% were male. NC was significantly correlated with age, BMI, waist circumference (WC), and body fat percentage (%BF). The NC of boys was greater than that of girls. The NC curves of smoothed 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were constructed by age and sex. Conclusions: NC can be used in the assessment of obesity in childhood. There was a positive correlation between NC and BMI, WC and %BF. This study was the first to provide NC percentiles for children in Brazil.

Normative health-related fitness values for children: analysis of 85347 test results on 9–17-year-old Australians since 1985

ObjectivesTo provide sex- and age-specific normative values for health-related fitness of 9–17-year-old Australians.MethodsA systematic literature search was undertaken to identify peer-reviewed studies reporting health-related fitness data on Australian children since...

Regional variations in the growth of Saudi children and adolescents.

BACKGROUND AND OBJECTIVES:No previous study has provided a detailed description of regional variations of growth within the various regions of Saudi Arabia. Thus, we sought to demonstrate differences in growth of children and adolescents in different regions.SUBJECTS AND METHODS:The 2005 Saudi reference was based on a cross-sectional representative sample of the Saudi population of healthy children and adolescents from birth to 18 years of age. Body measurements of the length, stature, weight, head circumference and calculation of the BMI were performed according to standard recommendations. Percentile construction and smoothing were performed using the LMS (lambda, mu and sigma) methodology, followed by transformation of all individual measurements into standard deviation scores. Factors such as weight for age, height for age, weight for height, and head circumference for children from birth to 3 years, stature for age, head circumference and body mass index for children between 2-18 years of age were assessed. Subsequently, variations in growth between the three main regions in the north, southwest, and center of Saudi Arabia were calculated, with the Bonferroni: method used to assess the significance of differences between regions.RESULTS:There were significant differences in growth between regions that varied according to age, gender, growth parameter and region. The highest variation was found between children and adolescents of the southwestern region and those of the other two regions The regression lines for all growth parameters in children <3 years of age were significantly different from one region to another reaching – 0.65 standard deviation scores for the southwestern regions (P=.001). However, the difference between the northern and central regions were not significant for the head circumference and for weight for length. For older children and adolescents a significant difference was found in all parameters except between the northern and central regions in BMI in girls and head circumference in boys. Finally, the difference in head circumference of girls between southwestern and northern regions was not significant. Such variation affected all growth parameters for both boys and girls.CONCLUSION:Regional variations in growth need to be taken into consideration when assessing the growth of Saudi children and adolescents.