Project description:AimsCardiovascular magnetic resonance (CMR) imaging is an important tool in the assessment of paediatric cardiac disease. Reported reference values of ventricular volumes and masses in the paediatric population are based on small cohorts and several methodologic differences between studies exist. We sought to create steady-state free precession (SSFP) CMR reference values for biventricular volumes and mass by combining data of previously published studies and re-analysing these data in a standardized manner.Methods and resultsA total of 141 healthy children (68 boys) from three European centres underwent cine-SSFP CMR imaging. Cardiac structures were manually contoured for end-diastolic and end-systolic phases in the short-axis orientation according to current standardized CMR post-processing guidelines. Volumes and masses were derived from these contours. Age-related reference curves were constructed using the lambda mu sigma method. Median age was 12.7 years (range 0.6-18.5). We report biventricular volumes and masses, unindexed and indexed for body surface area, stratified by age groups. In general, boys had approximately 15% higher biventricular volumes and masses compared with girls. Only in children aged <6 years old no gender differences could be observed. Left ventricle ejection fraction was slightly higher in boys in this study population (median 67% vs. 65%, P = 0.016). Age-related reference curves showed non-linear relations between age and cardiac parameters.ConclusionWe report volumetric SSFP CMR imaging reference values for children aged 0-18 years old in a relatively large multi-centre cohort. These references can be used in the follow-up of paediatric cardiac disease and for research purposes.
Project description:BackgroundCurrently used pediatric kidney length normative values are based on small single-center studies, do not include kidney function assessment, and focus mostly on newborns and infants. We aimed to develop ultrasound-based kidney length normative values derived from a large group of European Caucasian children with normal kidney function.MethodsOut of 1,782 children aged 0-19 years, 1,758 individuals with no present or past kidney disease and normal estimated glomerular filtration rate had sonographic assessment of kidney length. The results were correlated with anthropometric parameters and estimated glomerular filtration rate. Kidney length was correlated with age, height, body surface area, and body mass index. Height-related kidney length curves and table were generated using the LMS method. Multivariate regression analysis with collinearity checks was used to evaluate kidney length predictors.ResultsThere was no significant difference in kidney size in relation to height between boys and girls. We found significant (p < 0.001), but clinically unimportant (Cohen's D effect size = 0.04 and 0.06) differences between prone vs. supine position (mean paired difference = 0.64 mm, 95% CI = 0.49-0.77) and left vs. right kidneys (mean paired difference = 1.03 mm, 95% CI = 0.83-1.21), respectively. For kidney length prediction, the highest coefficient correlation was observed with height (adjusted R2 = 0.87, p < 0.0001).ConclusionsWe present height-related LMS-percentile curves and tables of kidney length which may serve as normative values for kidney length in children from birth to 19 years of age. The most significant predictor of kidney length was statural height.
Project description:BackgroundThe reference values of eNO have certain differences among people of different countries and races. We aimed to obtain the reference value of eNO in healthy children and adolescents (6-18 years old) in China and to explore the associations between the reference values with ages, gender, heights, BMI, and regions.MethodsWe measured FeNO50 levels in 5949 healthy Chinese children and adolescents, FeNO200 and CaNO levels in 658 participants from 16 provinces of 7 administrative areas in China aged 6-18. All persons were studied after obtaining informed consent from children and their parents.ResultsThe mean FeNO50 of 5949 Chinese children and adolescents aged 6-18 years was 14.1 ppb, with a 95% confidence interval of 1-38.1 ppb. The mean FeNO200 of 658 persons was 6.9 ppb with a 95% upper confidence interval of 15.0 ppb, and the mean CaNO was 3.0 ppb with a 95% upper confidence interval of 11.2 ppb. In the 6-11 age group, age and height were correlated with the logarithm of FeNO50 (P < 0.001, P < 0.05). There was no significant correlation between the logarithm of FeNO200 and gender, age, height and BMI (all P > 0.05). The logarithm of CaNO was correlated with gender (P < 0.05). In the 12-18 age group, gender, height, and region were correlated with the logarithm of FeNO50 (all P < 0.001). There was only a weak correlation between the logarithm of FeNO200 and height (P < 0.001). The logarithm of CaNO was negatively correlated with age (P < 0.05).ConclusionsHigher FeNO50, FeNO200 and CaNO values were found in healthy children and adolescents in China compared with foreign reports, and is affected by age, height, gender, and region. This study provides useful references for clinical application of eNO in children, especially Asian children.
Project description:PurposeThe purpose of this study was to summarize the flicker electroretinogram responses (ERGs) in healthy children using RETeval, a small handheld mydriasis-free full-field flicker ERG system.MethodsFlicker ERGs were recorded with the use of the RETeval system in 204 healthy children (aged 18 years and below) from 2 countries, China and the United States. The effects on ERG measurements of the subject's demographics and location were analyzed.ResultsThe implicit times have no correlation with the population (China cohort and US cohort), sex, and refractive error. In contrast, the amplitudes were dependent on demographics. The amplitude differences were small compared to the 95% reference interval; therefore, a single (age-corrected) reference interval can be used in both locations and both sexes. The implicit times and amplitudes mature over the first decade of life with exponential time constants of 2.5 years and 4.1 years, respectively, whereas most of the trend is within the first 6 years (implicit times) and 9 years (amplitudes).ConclusionsThe age dependence and percentiles obtained in this study could serve as reference data against which the ERG responses from pediatric patients can be compared.Translational relevanceThe flicker ERG is one of the standard methods for the assessment and diagnosis of vision-related disorders. This study provides reference data in pediatric subjects, which can then be used to aid in the interpretation of flicker ERG results.
Project description:The assessment of body composition in pediatric population is essential for proper nutritional support during hospitalization. However, currently available methods have limitations. This study aims to propose a novel approach for nutrition status assessment and introduce magnetic resonance imaging (MRI)-derived subcutaneous and visceral fat normative reference values. A total of 262 healthy subjects aged from 6 to 18 years underwent MRI examinations and anthropometric measurements. MRI images at the second lumbar vertebrae were used by two radiologists to perform the semi-automatic tissue segmentation. Based on obtained adipose tissue surface areas and body mass index (BMI) scores sex-specific standard percentile curves (3rd, 10th, 25th, 50th, 75th, 90th, 97th) and z-scores were constructed using LMS method. Additionally, 85th and 95th centiles of subcutaneous and visceral adipose tissue were proposed as equivalents of overweight and obesity. Bland-Altman plots revealed an excellent intra-observer reproducibility and inter-observer agreement. In conclusion, our findings demonstrate highly reproducible method and suggest that MRI-derived reference values can be implemented in clinical practice.
Project description:Although there are over 1.34 billion Chinese in the world, nationwide spirometric reference values for Chinese are unavailable, which is usually based on Caucasian conversion. The aim of this study was to establish spirometric reference values for Chinese with a national wide sample.We enrolled healthy non-smokers in 24 centers in Northeast, North, Northwest, Southwest, South, East and Central China from January 2007 to June 2010. Spirometry was performed according to American Thoracic Society and European Respiratory Society guidelines. Reference equations were established using the Lambda-Mu-Sigma (LMS) method for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow (PEF) and maximal midexpiratory flow (MMEF). Popular Caucasian reference values adjusted with ethnic conversion factors were validated with Chinese measured spirometry data. The present study also compared with other published Chinese equations for spirometry.A total of 7,115 eligible individuals aged 4 to 80 years (50.9% females) were recruited. Reference equations against age and height by gender were established, including predicted values and lower limits of normal (LLNs). Validated with Chinese data, the mean percentage differences of Caucasian reference values adjusted with ethnic conversion factors were -10.2% to 1.8%, and the percentages of total subjects under LLNs were 0.1% to 8.9%. Compared with this study, the percentage differences of previous Chinese studies ranged from -17.8% to 11.4%, which were found to significantly overestimate or underestimate lung function.This study established new reference values for better interpretation of spirometry in Chinese aged 4 to 80 years, while Caucasian references with adjustment were inappropriate for Chinese.
Project description:BackgroundHandgrip strength (HGS) is an indicator of muscle strength, suited for evaluating the aging process. Its use depends on the availability of reliable normative reference values (NRV). The main objective of this study is to provide NRV of HGS for Brazilians aged 65 to 90 years.MethodsParticipants were from the Frailty in Brazilian Older People research. 2,999 successful aging (SA) participants comprised the development sample. HGS was measured using a hydraulic dynamometer. Obtaining NRV involved regressing HGS on age per sex-height strata, fitting separate fractional polynomial (FP) models for the mean and coefficient of variation. Model fit was assessed via standardized residuals, probability/quantile plots, and comparing observed to normal expected percentages of participants falling within specified centile intervals. For validation, the latter procedure was applied to 2,369 unsuccessfully aging (UA) participants.ResultsAcross strata, the best-fitting models for the means were FP of power 1. FP models for the CV indicated age invariance, entailing steady heteroscedastic age decline in SD since coefficients for the means were negative and SD = CV×mean. All models adjusted well. Centiles distributions for the SA and UA populations showed anticipated patterns, respectively falling on and below the normative expected centile references. Results (NRV) are presented in tables and centile charts. Equations are also provided.ConclusionNRV/charts may be endorsed for routine use, while still tested further. They would aid professionals caring for older people, not only to identify those at risk and eligible for immediate provisions, but also in planning prevention and rehabilitation measures.
Project description:BACKGROUND:Prader-Willi syndrome (PWS) is a multisystem genetic disorder, which has a typical eating behavior and growth pattern. In the infancy period, children with PWS have low body weight followed by hyperphagia in later childhood. Disease-specific growth charts have been recommended for monitoring PWS patients. Previous literature demonstrated growth differences among individuals with PWS of different ethnicity. METHODS:A retrospective multicenter study was performed in PWS patients from different areas of Thailand included collaboration with the Thai PWS support group during 2000-2017. Baseline characteristics and anthropometric data were reviewed. Both growth hormone and non-growth hormone received patients were included, but the data after receiving GH were excluded before curve construction. Growth charts for Thai PWS compared to the 50th normative centile were constructed using Generalized Least Squares (GLS) methods. Curve smoothing was performed by Fractional Polynomials and Exponential Transformation. RESULT:One hundred and thirteen patients with genetically confirmed PWS (55 males and 58 females) were enrolled. Fifty percent of patients were diagnosed less than 6?months of age. We developed growth charts for non-growth hormone treated Thai children with PWS aged between 0 and 18?years. A growth pattern was similar to other ethnicities while there were some differences. Mean birth weight of PWS patients was less than that of typical newborns. Mean adult height at 18?years of age in Thai children with PWS was lower than that in American children, but taller than Japanese. Mean weight of Thai PWS males at 18?years of age was more than those from other countries. CONCLUSION:This study is the first to document PWS-specific growth charts in Southeast Asian population. These growth charts will be useful in improving the quality of patient care and in evaluating the impact of growth hormone treatment in the future.
Project description:BackgroundIncreasing attention has been drawn on the assessment of body composition phenotypes, since the distribution of soft tissue influences cardio-metabolic risk. Dual-energy X-ray absorptiometry (DXA) is a validated technique to assess body composition. European reference values from population-based cohorts are rare.AimsTo provide age- and sex-related reference values of body composition parameters and visceral adipose tissue (VAT) mass, and for lean mass index (LMI) with regard to fat mass index (FMI) quantities and BMI categories.MethodsGE-Lunar Prodigy DXA scans of 10.894 participants, aged 18-81 years, recruited from 2011 to 2019 by the Austrian LEAD study, a population-based cohort study, have been used to construct reference curves using the LMS method. Parameters assessed are FMI, LMI, appendicular LMI, fat mass ratios android/gynoid and trunk/limbs, and VAT.ResultsAll lean mass and fat mass parameters indicating central fat accumulation were higher in men, whereas other fat mass indices were higher in women. LMI differed between each FMI subgroup (low vs. normal, low vs. high, normal vs. high), and BMI category in all ages and LMI increased with FMI and BMI classes. VAT mass was higher in men compared with women and increased across all age groups within both sexes.ConclusionThe present study provides age- and sex-related reference values for European adults aged 18-81 years for body composition parameters and VAT mass for Lunar Prodigy DXA. In addition, this study reports LMI reference values with regard to fat mass quantities, showing a positive association with increasing FMI percentiles and BMI categories.