Characteristics of casein phosphopeptides in Chinese human milk and its correlation with infant growth: A cross-sectional study

This research aimed to investigate the characteristics of casein phosphopeptides in Chinese human milk, and their potential relationship to infant growth. Using the liquid chromatography-Orbitrap-mass spectrometry technique, a total of 15 casein phosphopeptides were identified from 200 human milk samples. Also, our results indicate that casein phosphopeptides were phosphorylated with only one phosphate. The relative concentrations of casein phosphopeptides at 6 months postpartum were increased compared with milk at 2 months (FDR < 0.05). Significantly positive correlations were observed between casein phosphopeptides and infant growth, as shown by four casein phosphopeptides were positively correlated with the infants' weight-for-age Z-scores (rs range from 0.20 to 0.29), and three casein phosphopeptides were positively correlated with the infants' length-for-age Z-scores (rs range from 0.19 to 0.27). This study is the first to reveal the phosphorylated level and composition of casein phosphopeptides in Chinese human milk, and their potential relationship with infant growth.

Normative computed tomography angiography values of the main and branch pulmonary arteries in children

Non-invasive cardiac imaging like echocardiogram, cardiac magnetic resonance imaging (CMR), and computed tomography angiography (CTA) play a key role in the diagnosis, aid in management and follow-up of congenital heart disease patients. Normative data for intracardiac and extracardiac vascular structures in children are currently available for echocardiogram, CMR, and non-gated CTA. We sought to establish systolic and diastolic normative data for main and branch pulmonary arteries in children using electrocardiogram (ECG)-gated CTA. Diameters and cross-sectional areas of the main and branch pulmonary arteries were measured in systole and diastole based on the aortic valve position (open versus closed) in 100 subjects who had ECG-gated cardiac CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area (BSAAE) was established using the previously described methods. A total of 100 children aged 0-18 years were analyzed; mean age was 5.3 years (SD, 6.1 years). Z-score curves were plotted in relation to the BSA for the mean, maximum, and minimum diameters and cross-sectional area of the main and branch pulmonary arteries for systole and diastole.   Conclusion: We report systolic and diastolic mean, maximum, and minimum diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children derived using ECG-gated cardiac CTA. We believe our results can help identify abnormally sized main and branch pulmonary arteries. What is Known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity. What is New: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children.

Combined Z-scores to assess the impact of rare autosomal trisomies that results in non-invasive prenatal screening on pregnancy outcomes

OBJECTIVE

This study aimed to combine Z-scores to evaluate the effects of rare autosomal trisomies (RATs) in non-invasive prenatal screening (NIPS) on pregnancy outcomes at a single center.

METHODS

We retrospectively collected the clinical data of women with high-risk RATs results using NIPS at a single center between January 2017 and December 2021. NIPS-positive results were separated into three groups based on the Z-value of RATs (Group1: 6 ≤ Z < 10; Group2: 10 ≤ Z < 15; Group 3: Z ≥ 15). Pregnancy outcomes of women with RATs were compared with the low-risk NIPS group.

RESULTS

Overall, 83 RATs were identified in 23,321 NIPS results at our center. Prenatal diagnosis was conducted for 55 patients, and no case was confirmed, with a positive predictive value (PPV) of zero. Fifteen of these patients had adverse pregnancy outcomes, including delivered preterm and/or birth weight (9/15, 60.0 %), structural abnormalities (4/15, 26.7 %), miscarriage (1/15, 6.7 %), and intrauterine death (1/15, 6.7 %). There were 8 (8/22, 36.4 %) adverse pregnancy outcomes in Group 3, which was significantly higher than that in the low-risk NIPS group (p < 0.01). No significant difference was observed between the control group and Group 1 and Group 2 (p > 0.01).

CONCLUSIONS

Clinicians should pay more attention to the RATs results when the Z-score is ≥ 15. The data are available for clinicians to guide the prenatal diagnosis of RATs and pregnancy management.

Inter-scanner comparability of Z-scores for native myocardial T1 and T2 mapping

BACKGROUND

Cardiovascular Magnetic Resonance (CMR) native T1 and T2 mapping serve as robust, contrast-agent-free diagnostic tools, but hardware- and software-specific sources of variability limit the generalizability of data across CMR platforms, consequently limiting the interpretability of patient-specific parametric data. Z-scores are used to describe the relationship of observed values to the mean results as obtained in a sufficiently large normal sample. They have been successfully used to describe the severity of quantifiable abnormalities in medicine, specifically in children and adolescents. The objective of this study was to observe whether z-scores can improve the comparability of T1 and T2 mapping values across CMR scanners, field strengths, and sequences from different vendors in the same participant rather than different participants (as seen in previous studies).

METHODS

Fifty-one healthy volunteers (26 men/25 women, mean age = 43 ± 13.51) underwent three CMR exams on three different scanners, using a Modified Look-Locker Inversion Recovery (MOLLI) 5-(3)- 3 sequence to quantify myocardial T1. For T2 mapping, a True Fast Imaging with steady-state free precession (TRUFI) sequence was used on a 3 T Skyra™ (Siemens), and a T2 Fast Spin Echo (FSE) sequence was used on 1.5 T Artist™ (GE) and 3.0 T Premier™ (GE) scanners. The averages of basal and mid-ventricular short axis slices were used to derive means and standard deviations of global mapping values. We used intra-class comparisons (ICC), repeated measures ANOVA, and paired Student's t-tests for statistical analyses.

RESULTS

There was a significant improvement in intra-subject comparability of T1 (ICC of 0.11 (95% CI= -0.018, -0.332) vs 0.78 (95% CI= 0.650, 0.866)) and T2 (ICC of 0.35 (95% CI= -0.053, 0.652) vs 0.83 (95% CI= 0.726, 0.898)) when using z-scores across all three scanners. While the absolute global T1 and T2 values showed a statistically significant difference between scanners (p < 0.001), no such differences were identified using z-scores (T1z: p = 0.771; T2z: p = 0.985). Furthermore, when images were not corrected for motion, T1 z-scores showed significant inter-scanner variability (p < 0.001), resolved by motion correction.

CONCLUSION

Employing z-scores for reporting myocardial T1 and T2 removes the variation of quantitative mapping results across different MRI systems and field strengths, improving the clinical utility of myocardial tissue characterization in patients with suspected myocardial disease.

Harmonization of CSF and imaging biomarkers in Alzheimer's disease: Need and practical applications for genetics studies and preclinical classification

In Alzheimer's disease (AD) research, cerebrospinal fluid (CSF) Amyloid beta (Aβ), Tau and pTau are the most accepted and well validated biomarkers. Several methods and platforms exist to measure those biomarkers, leading to challenges in combining data across studies. Thus, there is a need to identify methods that harmonize and standardize these values. We used a Z-score based approach to harmonize CSF and amyloid imaging data from multiple cohorts and compared GWAS results using this approach with currently accepted methods. We also used a generalized mixture model to calculate the threshold for biomarker-positivity. Based on our findings, our normalization approach performed as well as meta-analysis and did not lead to any spurious results. In terms of dichotomization, cutoffs calculated with this approach were very similar to those reported previously. These findings show that the Z-score based harmonization approach can be applied to heterogeneous platforms and provides biomarker cut-offs consistent with the classical approaches without requiring any additional data.

Anticoagulation use is associated with lower fetal fraction and more indeterminate results

BACKGROUND

Maternal anticoagulation use may increase indeterminate result rates on cell-free DNA-based screening, but existing studies are confounded by inclusion of individuals with autoimmune disease, which alone is associated with indeterminate results. Changes in chromosome level Z-scores are proposed by others as a reason for indeterminate results, but the etiology of this is uncertain.

OBJECTIVE

This study aimed to evaluate differences in fetal fraction, indeterminate result rate, and total cell-free DNA concentration in individuals on anticoagulation without autoimmune disease compared with controls undergoing noninvasive prenatal screening. Secondly, using a nested case-control design, we evaluated differences in fragment size, GC-content, and Z-scores to evaluate laboratory-level test characteristics.

STUDY DESIGN

This was a retrospective single-institution study of pregnant individuals undergoing cell-free DNA-based noninvasive prenatal screening using low-pass whole-genome sequencing between 2017 and 2021. Individuals with autoimmune disease, suspected aneuploidy, and cases where fetal fraction was not reported were excluded. Anticoagulation included heparin-derived products (unfractionated heparin, low-molecular-weight heparin), clopidogrel, and fondaparinux, with a separate group for those on aspirin alone. An indeterminate result was defined as fetal fraction <4%. We evaluated the association between maternal anticoagulation or aspirin use, and fetal fraction, indeterminate results, and total cell-free DNA concentration using univariate and multivariate analyses, controlling for body mass index, gestational age at sample collection, and fetal sex. For the anticoagulation cohort, we compared laboratory-level test characteristics among cases (on anticoagulation) and a subset of controls. Lastly, we evaluated for differences in chromosome level Z-scores among those on anticoagulation with and without indeterminate results.

RESULTS

A total of 1707 pregnant individuals met the inclusion criteria. Of those, 29 were on anticoagulation and 81 were on aspirin alone. For those on anticoagulation, the fetal fraction was significantly lower (9.3% vs 11.7%; P<.01), the indeterminate result rate was significantly higher (17.2% vs 2.7%; P<.001), and the total cell-free DNA concentration was significantly higher (218 pg/μL vs 83.7 pg/μL; P<.001). Among those on aspirin alone, the fetal fraction was lower (10.6% vs 11.8%; P=.04); however, there were no differences in the rate of indeterminate results (3.7% vs 2.7%; P=.57) or total cell-free DNA concentration (90.1 pg/μL vs 83.8 pg/μL; P=.31). After controlling for maternal body mass index, gestational age at sample collection, and fetal sex, anticoagulation was associated with an >8-fold increase in the likelihood of an indeterminate result (adjusted odds ratio, 8.7; 95% confidence interval, 3.1-24.9; P<.001), but not aspirin (adjusted odds ratio, 1.2; 95% confidence interval, 0.3-4.1; P=.8). Anticoagulation was not associated with appreciable differences in cell-free DNA fragment size or GC-content. Although differences in chromosome 13 Z-scores were observed, none were observed for chromosomes 18 or 21, and this difference did not contribute to the indeterminate result call.

CONCLUSION

In the absence of autoimmune disease, anticoagulation use, but not aspirin, is associated with lower fetal fraction, higher total cell-free DNA concentration, and higher rates of indeterminate results. Anticoagulation use was not accompanied by differences in cell-free DNA fragment size or GC-content. Statistical differences in chromosome level Z-scores did not clinically affect aneuploidy detection. This suggests a likely dilutional effect by anticoagulation on cell-free DNA-based noninvasive prenatal screening assays contributing to low fetal fraction and indeterminate results, and not laboratory or sequencing-level changes.

Serum levels of bone turnover markers including calculation of Z-scores: Data from a Dutch healthy reference cohort

Introduction

Bone turnover markers (BTM) are biochemical compounds reflecting different stages of bone metabolism. Their levels change with age and differ between males and females. This makes clinical interpretation and comparison more difficult. Therefore, our aim was to establish BTM reference values which can be used to calculate Z-scores for use in daily clinical practice.

Methods

Serum markers of collagen resorption, bone formation/regulation, collagen formation and bone mineralization (sCTX, OC, PINP and BALP, respectively) were measured in non-fasting volunteers without bone-related abnormalities. Raw data was plotted and gender-specific age cohorts were established with their respective means and standard deviations (SD). Z-scores can be calculated using these reference values to correct for the influence of age and gender on BTM.

Results

In total, 856 individuals were included of which 486 (57 %) were female. Individuals were aged between 7 and 70 years. Highest serum levels of BTM were found in childhood and puberty. Peak levels are higher in boys than girls and prevail at later ages. In adults, BTM levels decrease before reaching stable nadir levels. In adults, 10-year reference cohorts with means and SD were provided to calculate Z-scores.

Conclusion

With our data, Z-scores of sCTX, OC, PINP and BALP can be calculated using reference categories (for age and gender) of Caucasian healthy volunteers. Clinicians can use BTM Z-scores to determine whether there are changes in bone turnover physiology beyond those expected during aging. BTM Z-scores facilitate harmonization of data interpretation in daily clinical practice and research.

Extracting the latent needs of dementia patients and caregivers from transcribed interviews in japanese: an initial assessment of the availability of morpheme selection as input data with Z-scores in machine learning

BACKGROUND

Given the increasing number of dementia patients worldwide, a new method was developed for machine learning models to identify the 'latent needs' of patients and caregivers to facilitate patient/public involvement in societal decision making.

METHODS

Japanese transcribed interviews with 53 dementia patients and caregivers were used. A new morpheme selection method using Z-scores was developed to identify trends in describing the latent needs. F-measures with and without the new method were compared using three machine learning models.

RESULTS

The F-measures with the new method were higher for the support vector machine (SVM) (F-measure of 0.81 with the new method and F-measure of 0.79 without the new method for patients) and Naive Bayes (F-measure of 0.69 with the new method and F-measure of 0.67 without the new method for caregivers and F-measure of 0.75 with the new method and F-measure of 0.73 without the new method for patients).

CONCLUSION

A new scheme based on Z-score adaptation for machine learning models was developed to predict the latent needs of dementia patients and their caregivers by extracting data from interviews in Japanese. However, this study alone cannot be used to assign significance to the adaptation of the new method because of no enough size of sample dataset. Such pre-selection with Z-score adaptation from text data in machine learning models should be considered with more modified suitable methods in the near future.

Extrauterine Growth Restriction: Need for an Accurate Definition

Neonates show considerable variation in growth that can be recognized through serial measurements of basic variables such as weight, length, and head circumference. If possible, measurement of subcutaneous and total body fat mass can also be useful. These biometric measurements at birth may be influenced by demographics, maternal and paternal anthropometrics, maternal metabolism, preconceptional nutritional status, and placental health. Subsequent growth may depend on optimal feeding, total caloric intake, total metabolic activity, genetic makeup, postnatal morbidities, medications, and environmental conditions. For premature infants, these factors become even more important; poor in utero growth can be an important reason for spontaneous or induced preterm delivery. Later, many infants who have had intrauterine growth restriction (IUGR) and are born small for gestational age (SGA) continue to show suboptimal growth below the 10th percentile, a condition that has been defined as extrauterine growth restriction (EUGR) or postnatal growth restriction (PNGR). More importantly, a subset of these growth-restricted infants may also be at high risk of abnormal neurodevelopmental outcomes. There is a need for well-defined criteria to recognize EUGR/PNGR, so that correctional steps can be instituted in a timely fashion.

Interlaboratory Comparison Investigations (ICIs) and External Quality Assurance Schemes (EQUASs) for human biomonitoring of perfluoroalkyl substances (PFASs) in serum as part of the quality assurance programme under HBM4EU

Perfluoroalkyl substances (PFASs) are of very high concern due to their persistence and accumulative behaviour as well as their manifold adverse health effects. Human biomonitoring (HBM) based on the determination of PFASs in serum samples is an adequate and established strategy for exposure and risk assessment of the population. The suspected health risks associated with exposure levels in the general population call for reliable HBM data verified by Quality Assurance and Quality Control (QA/QC) measures. PFASs were among the chemicals selected as priority substances in HBM4EU, a pan-European project to harmonize and advance HBM within 30 European countries. For this purpose, the analytical comparability and accuracy of PFASs-analysing laboratories was assessed in a QA/QC programme comprising Interlaboratory Comparison Investigations (ICIs) and External Quality Assurance Schemes (EQUASs). This paper presents the evaluation process and discusses the results of four ICI/EQUAS rounds for the determination of eight perfluoroalkyl carboxylic acids and four perfluoroalkyl sulfonic acids (PFBS, PFHxS, PFHpS, PFOS) in serum. All 21 participating laboratories achieved satisfactory results for at least six of these biomarkers, although low limits of quantification (of about 0.1 μg/L) were required to quantify serum PFAS levels at general population exposure levels. The mean relative standard deviation of the participants' results (study RSD_R) significantly improved from 22 % to 13 % over all PFAS biomarkers in the course of the four rounds. This QA/QC programme succeeded in establishing a network of laboratories with high analytical comparability and accuracy for the analysis of PFASs across 12 European countries.

Interlaboratory assessments for dioxin-like POPs (2016/2017 and 2018/2019)

In the two rounds of the UNEP-coordinated 'Biennial interlaboratory assessments of POPs laboratories, which were implemented in 2016/2017 and 2018/2019, 56 and 46 laboratories submitted results for dioxin-like persistent organic pollutants (dl-POPs). Test matrices consisted of solutions of analytical standards and naturally contaminated sediment, air extract, fish and human milk. Performance assessment using z-scores so that satisfactory performance corresponded to 2 z = ±25%, which is recommended for laboratories submitting data to the global monitoring plan of the Stockholm Convention on POPs. Participation has shown that analytical capacity for analyzing dl-POPs exist in all UN regions; however, in Africa and Central and Eastern European countries capacities are (very) limited; in Latin America capacity is increasing. The presence of dioxin laboratories is not limited to industrialized or OECD countries but also present in developing countries such as China, Brazil, Egypt, Thailand, or Vietnam. Laboratories using established methods based on gas chromatographs coupled to high-resolution mass spectrometers (sector field instruments only) by far had the best results. Among the test samples, human milk and especially fish in the last round posed severe problems to all laboratories so that performance must improve, especially in foodstuffs at (very) low concentrations.

Comparability of different Z-score equations for aortic root dimensions in children with Marfan syndrome

BACKGROUND

Aortic root dilation is a major complication of Marfan syndrome and is one of the most important criteria in establishing the diagnosis. Currently, different echocardiographic nomograms are used to calculate aortic root Z-scores. The aim of the present study was to assess the potential differences in aortic root measurements when aortic root Z-scores were obtained in a cohort of paediatric Marfan patients using several published nomograms.

METHODS

In a cohort of 100 children with Marfan syndrome, Z-scores for aortic root dimensions were calculated according to the nomograms of Pettersen et al, Gautier et al, Colan et al, and Lopez et al. Bland-Altman plots were used to estimate mean differences in Z-scores and to establish limits of agreement.

RESULTS

The mean Z-score of the sinus of Valsalva for Lopez et al was significantly higher compared to Gautier et al (p < 0.01) and Pettersen et al (p = 0.03). The nomogram of Lopez et al resulted in substantially higher Z-scores in patients with a large sinus of Valsalva diameter. Thirty-five percentage of the studied patients would have a Z-score ≥ 2 using Lopez et al compared to 20% for Pettersen et al, 21% for Gautier et al, and 33% for Colan et al.

CONCLUSION

The currently available nomograms for calculating Z-scores of aortic dilation in children with Marfan syndrome lead to clinically relevant differences in Z-scores, especially in children with a relative large aortic root diameter. This could have impact on both the diagnosis and treatment of patients with Marfan syndrome.

The Optimal Cutoff Value of Z-scores Enhances the Judgment Accuracy of Noninvasive Prenatal Screening

Objective

To evaluate the accuracy of Z-scores of noninvasive prenatal screening (NIPS) in predicting 21, 18 trisomy, and X chromosome aneuploidy.

Methods

A total of 39,310 prenatal women were recruited for NIPS from September 2015 to September 2020. Interventional prenatal diagnosis was applied to verify the diagnosis of NIPS-positive results. Logistic regression analysis was employed to relate the Z-scores to the positive predictive value (PPV) of NIPS-positive results. Using receiver operating characteristic (ROC) curves, we calculated the optimal cutoff value of Z-scores to predict fetal chromosome aneuploidy. According to the cutoff value, NIPS-positive results were divided into the medium Z-value (MZ) and high Z-value (HZ) groups, and PPV was calculated to access the accuracy of Z-scores.

Results

A total of 288 effective values of Z-scores were used as the final data set. The logistics regression analysis revealed that Z-scores were significantly associated with true-positive results for 21 trisomy (T21) and 18 trisomy (T18) (P < 0.05), whereas the same was not observed for X chromosome aneuploids (P > 0.05). The optimal cutoff value of the Z-score for T21, T18, XO, XXX, and XXY indicated by ROC curve analysis were 5.79, 6.05, −9.56, 5.89, and 4.47, and the area under the curve (AUC) were 0.89, 0.80, 0.48, 0.42, and 0.45, respectively. PPV in the HZ group was higher than that in the MZ group, and the application of the cutoff value reduced the false discovery rate (FDR), which was only 2.9% in the HZ group compared with 61.1% in the MZ group for T21 and T18. The difference in total PPV between the MZ and HZ groups for X chromosome aneuploids was statistically significant. Moreover, the PPV for XXX and XXY seemed to increase with Z-scores but not for XO.

Conclusion

The Z-score is helpful for the accurate judgment of NIPS results and for clinical prenatal counseling. Especially for T21 and T18, Z-scores have an excellent clinical association, which is superior to that seen with X chromosome aneuploids. In addition, using Z-scores to judge NIPS results offers a certain reference value for XXX and XXY but not for XO.

Frequency, diagnosis, pathogenesis and management of osteoporosis in alkaptonuria: data analysis from the UK National Alkaptonuria Centre

Osteoporosis and fractures are common features of alkaptonuria.

INTRODUCTION

A large cohort of alkaptonuria (AKU) patients was studied to better recognise and characterise osteoporosis and fractures in AKU.

METHODS

Assessments including questionnaire analysis, DEXA and CT densitometry at the neck of femur (FN), total hip (TH) and lumbar spine (LS) were performed on patients at baseline when 2 mg nitisinone was commenced, and yearly thereafter. Blood and urine samples were collected for chemical measurement. CT BMD Z-scores were generated.

RESULTS

Between June 2007 and March 2020, 87 AKU patients attended the NAC. At baseline, there were 48 fractures in 39 patients. Prevalence of osteoporosis was 3.1 at FN, 10.8 at TH and 24.7% at LS respectively. Prevalence of fragility fractures was greatly increased at 44.8%. The group with fractures showed increased ochronosis scores (p < 0.05). CT LS showed an inverse relationship with fractures (R = - 0.28; p < 0.05). CT LS was significantly lower in the fracture group (p < 0.002). Following nitisinone only, CT FN and CT TH decreased significantly (p < 0.05 and 0.01 respectively). Following nitisinone plus antiresorptive therapy, CT FN, CT TH and CT LS all increased significantly (p < 0.05, 0.05 and 0.001 respectively). However, patients on nitisinone plus antiresorptive had more fractures than nitisinone and no-treatment groups (p < 0.05).

CONCLUSIONS

Osteopenia and fragility fractures are common in AKU.. Anti-resorptive therapy increased BMD in AKU without decreasing fragility fractures. Bone densitometry measurements by DXA are less reliable than quantitative CT at the LS in AKU.

Low selenium intake is associated with postpartum weight retention in Chinese women and impaired physical development of their offspring

The aim of this study was to investigate the association between daily Se intake and postpartum weight retention (PPWR) among Chinese lactating women, and the impact of their Se nutritional status on infants' physical development. Se contents in breast milk and plasma collected from 264 lactating Chinese women at the 42nd day postpartum were analysed with inductively coupled plasma MS. Daily Se intake was calculated based on plasma Se concentration. The dietary data of 24-h records on three consecutive days were collected. Infant growth status was evaluated with WHO standards by Z-scores. Linear regression analyses and multinomial logistic regression were conducted to examine the impact of Se disequilibrium (including other factors) on PPWR and growth of infants, respectively. The results indicated that: (1) the daily Se intake of the subjects was negatively associated with their PPWR (B = -0·002, 95 % CI - 0·003, 0·000, P = 0·039); (2) both insufficient Se daily intake (B = -0·001, OR 0·999, 95 % CI 0·998, 1·000, P = 0·014) and low level of Se in milk (B = -0·025, OR 0·975, 95 % CI 0·951, 0·999, P = 0·021) had potential associations with their infants' wasting, and low level of Se in milk (B = -0·159, OR 0·853, 95 % CI 0·743, 0·980, P = 0·024) had a significant association with their infants' overweight. In conclusion, the insufficient Se nutritional status of lactating Chinese women was first found as one possible influencing factor of their PPWR as well as low physical development of their offspring.

Z-score values of left ventricular dimensions in adolescent elite male soccer players

Recent studies showed contrasting findings in morphological changes due to competitive soccer in adolescent players (SP). We present a prospective study in 315 consecutive adolescent (10-14 years) male elite SP and 53 healthy matched active controls (CON). All participants underwent a complete transthoracic two-dimensional echocardiography (TTE). The mean age in SP was 12.8 ± 0.65 years compared to 12.6 ± 0.8 years in CON. For all left ventricular (LV) dimensions, mean Z-score values were higher in SP. There was a significant Z-score increase in interventricular septum diastolic diameter (2.47z vs. 1.62z, p < 0.05), left ventricular posterior wall diastolic and systolic diameter (1.15z vs. 0.47z, p < 0.05 and 1.05z vs. - 0.4z, p < 0.05). Athletes had significant greater LV mass indexed for BSA (94 ± 12 g/m² vs. 81 ± 13 g/m², p < 0.05). There was no significant difference in LV function or diameters. Conclusion: Our findings suggest that elite soccer training in adolescent male is a type of sport predominantly related to cardiac resistance remodeling. Adolescent SP may develop supernormal left ventricular wall dimensions (+ 2.0 to + 2.5z). If in SP Z-scores, any LV dimension above + 2.5 is measured, primary or secondary cardiomyopathies should be excluded. What is Known: • Morphological cardiac adaptation in response to exercise depends on the type, duration, and intensity of training. • Morphological and functional changes due to competitive sports (athlete's heart) occur even in pre-adolescent athletes. What is New: • Our findings point out that German elite soccer training in adolescent male (10-14 years of age) is a type of sport predominantly related to cardiac resistance remodeling. • If in an adolescent competitive soccer player any LV dimension Z-score value above + 2.5 is measured, a primary or secondary cardiomyopathy should be excluded.

[Evaluation of a measurement tool with real-time display of the standard value for fetal biometrics]

OBJECTIVES

Most of the ultrasound machines include a tool allowing real-time display of the standard value of the biometric measurement being taken. Our hypothesis was that this tool influences the sonographer as measurements are taken, by inducing a normalization, thus a tendency towards the 50th percentile. The objective of this study was to evaluate the impact of a real-time display of the standard value in prenatal ultrasound screening.

METHODS

We conducted an observational, prospective, controlled and open study including all patients who underwent a prenatal ultrasound scan in the 2nd or 3rd trimester at the University Hospitals in Strasbourg between December 2017 and June 2018. Exclusion criteria were the presence of a fetal morphological abnormality or a karyotypic abnormality. The tool being tested was the real-time display on screen of the gestational age, of which the measurement corresponds to the 50th percentile. The measurements were retrospectively transformed into Z-scores. The main end-point was to compare the distribution of Z-scores between the groups.

RESULTS

We included 3551 ultrasound examinations: 696 performed with the tool and 2796 performed without. Fifty-nine scans were excluded due to morphological abnormalities. There was no statistically significant difference between the Z-scores distributions of measurements performed with or without the tool, regardless of the parameter studied. There was also no difference in the detection of pathological measurements: below the 10th percentile or above the 90th percentile.

CONCLUSION

The use of such a tool does not seem to be detrimental to biometric screening, but on the other hand does not seem useful either.

Comparing the validity of continuous metabolic syndrome risk scores for predicting pediatric metabolic syndrome: the CASPIAN-V study

Background The aim of this study was to compare the validity of various approaches to pediatric continuous metabolic syndrome (cMetS) scores including siMS scores (2 waist/height + fasting blood glucose [FBG]/5.6 + triglycerides [TG]/1.7 + systolic blood pressure [BP]/130 + high-density lipoprotein [HDL]/1.02), Z-scores, principal component analysis (PCA) and confirmatory factor analysis (CFA) for predicting metabolic syndrome (MetS). Methods This nationwide cross-sectional study was conducted on 4200 Iranian children and adolescents aged 7-18 years. The cMetS was computed using data on HDL, cholesterol, TGs, FBG, mean arterial pressure (MAP) and waist circumference (WC). The areas under the receiver operating characteristic curves (AUCs) were used to compare the performances of different cMetS scores. Results Data of 3843 participants (52.4% boys) were available for the current study. The mean (standard deviation [SD]) age was 12.6 (3) and 12.3 (3.1) years for boys and girls, respectively. The differences in AUC values of cMetS scores were significant based on the Delong method. The AUCs (95% confidence interval [CI]) were for Z-scores, 0.94 (0.93, 0.95); first PCA, 0.91 (0.89, 0.93); sum PCA, 0.90 (0.88, 0.92), CFA, 0.79 (0.76, 0.3) and also for siMS scores 1 to 3 as 0.93 (0.91, 0.94), 0.92 (0.90, 0.93), and 0.91 (0.90, 0.93), respectively. Conclusions The results of our study indicated that the validity of all approaches for cMetS scores for predicting MetS was high. Given that the siMS scores are simple and practical, it might be used in clinical and research practice.

Functional cardiac measurements performed by two-dimensional Doppler echocardiography in normal fetuses: Determination of Z-scores and future prospects

Two-dimensional (2D) echocardiogram with the aid of color Doppler and pulsed Doppler allows one to record blood flow waveforms in several structures of the heart. The determination of normal values of these flows in the fetus can help understand cardiac hemodynamics. Given this importance, numerous surveys have been conducted with various existing echocardiographic techniques in order to improve the functional evaluation and consequently, planning of delivery. The aim of this review was to discuss the findings of the reference values of blood flows obtained by 2D echocardiography with Doppler, the current trend of the determination of Z-scores in the functional measurements, and their future prospects.

Normal reference ranges for aortic diameters in preterm infants

OBJECTIVE

To establish normal reference ranges and Z-scores for aortic diameters in preterm infants according to the body surface area and assess their correlation with body weight, body surface area, and gestational age.

PATIENTS AND METHODS

In a prospective study, 268 preterm infants who fulfilled the criteria for inclusion were examined. Echocardiograms were performed to measure the ascending aorta, transverse aorta, and aortic isthmus diameters on 0 days to 6 days of life and at weekly intervals until the babies reached 36 weeks. Body surface area was divided into 13 groups from 0.07 m2 to 0.19 m2.

RESULTS

The mean gestational age was 29.8 [± 2.38 standard deviation (SD)] weeks, ranging from 24 weeks to 35 weeks. The mean body weight was 1479 (± 413 SD) g, ranging from 588 g to 3380 g, and the mean body surface area was 0.13 m2, ranging from 0.07 m2 to 0.19 m2. All the aortic diameters correlated well with both body weight and body surface area. Reference ranges with the mean ± SD, range, and Z-scores were calculated for aortic diameters according to the body surface area. A significant gradual increase was observed in ascending aorta, transverse aorta, and aortic isthmus diameters with increasing body surface area. Overall, a progressive and significant increase in ascending aorta, transverse aorta, and aortic isthmus diameters was observed during the first 9 weeks of life.

CONCLUSION

The ascending aorta, transverse aorta, and aortic isthmus diameters exhibited a significant correlation with the body surface area and body weight. This study provides reference data with Z-scores that can be used as a normal reference tool for the ascending aorta, transverse aorta, and aortic isthmus diameters for preterm infants based on the body surface area.

Normal Reference Ranges for Pulmonary Artery Diameters in Preterm Infants

To establish normal reference ranges and Z-scores for pulmonary artery diameters in preterm infants and their correlation with body surface area, body weight, and chronological age. In a prospective study, 268 preterm infants, who fulfilled the inclusion criteria were examined. Echocardiograms were performed to measure the main pulmonary artery, right pulmonary artery, and left pulmonary artery diameters on day(s) 0 to -6 of life and at weekly intervals until they reached 36 weeks of age. Body surface area was divided into thirteen groups from 0.07 to 0.19 m². The mean gestational age was 29.8 (±2.38 SD) weeks, ranging between 24 and 35, the mean body weight was 1479 (±413 SD) grams, ranging between 588 and 3380, and the mean body surface area was 0.13 m², ranging between 0.07 and 0.19 m². All the pulmonary artery diameters correlated well with both body weight and body surface area. Reference ranges, with mean ± SD, range, and Z-scores for aortic diameters according to body surface area were calculated. A significant gradual increase was observed in main and branch pulmonary artery diameters with increasing body surface area. Overall, a progressive and significant increase for main and branch pulmonary artery diameters was observed during the first nine weeks of life. The main and branch pulmonary artery diameters were found to have significant correlation with body surface area. The study also provides reference data with Z-scores, which can be used as a normal reference tool for measuring the main pulmonary artery, right, and left pulmonary artery diameters of preterm infants against body surface area.

Comparison of coronary sinus diameter Z-scores in normal fetuses and fetuses with persistent left superior vena cava (PLSVC)

To establish Z-score reference ranges for coronary sinus (CS) diameter in normal fetuses and explore the diagnostic value of CS Z-score in fetuses with persistent left superior vena cava (PLSVC). Study of 235 normal fetuses and 30 fetuses with PLSVC was involved. Noncardiac biometrical parameters included biparietal diameter (BPD), femoral length (FL), heart area (HA), gestation age (GA). The coronary sinus systolic and diastolic diameter (CSDs and CSDd ) were measured at the end of systole and diastole. CSDs and CSDd Z-score models were constructed by using linear regression analysis with Non-cardiac biometrical parameters as independent variables. Z-scores between normal fetuses and fetuses with PLSVC were compared. A simple, linear regression model was the best description and correlations between fetal CSDs and CSDd and four independent variables were excellent. Reference ranges for predicting means and SDs of the fetal CS were established. Equations for Z-score calculation were provided, CSDs and CSDd Z-scores were statistically different between normal fetuses and those with PLSVC. Development of CSDs and CSDd Z-score reference ranges in normal fetuses was realized. The CSDs and CSDd Z-scores can provide quantitative evidence in prenatal diagnosis of PLSVC.

Forearm bone mass predicts mortality in chronic hemodialysis patients

We aim to determine the relationship between bone mineral density (BMD), measured by T- and Z-score, and mortality risk in hemodialysis (HD) patients. We also investigate which are the most suitable skeletal sites for predicting mortality rate. We analyzed the survival of 102 patients who had been treated with chronic HD according to BMD. Patients with a T-score ≤2.5 at the middle, ultradistal and proximal part of the forearm had a higher mortality risk than those with a T-score of -2.5 or higher. Furthermore, no statistically significant association was found between loss of bone mass at other measuring points-lumbar spine (anteroposterior orientation from L1-L4) and hip (neck, trochanter, intertrochanter, total and Ward's triangle)-and mortality risk. We were also interested in exploring the relationship between Z-score at different skeletal regions and mortality risk. We found that patients with a Z-score of -1 or lower at all three parts of the forearm had a greater mortality risk. It is also worth noting that the Z-score at all three parts of the forearm was a more apparent predictor of mortality, compared to the T-score at the same skeletal regions. This empirical analysis showed that BMD assessments should be obtained at the forearm, due to the good predictability of this skeletal site regarding mortality of HD patients. Moreover, data concerning bone density should be reported as Z-scores.

Echocardiographic reference ranges in older children and adolescents in sub-Saharan Africa

Background

Echocardiographic reference ranges are important to identify abnormalities of cardiac dimensions. Reference ranges for children in sub-Saharan Africa have not been established. The aim of this study was to establish echocardiographic z-score references for Black children in sub-Saharan Africa.

Methods

282 healthy subjects aged 6–16 years (143 [51%] males) with no known history of cardiac disease were enrolled in the study in Harare, Zimbabwe between 2014 and 2016. Standard M-mode echocardiography was performed and nine cardiac chamber dimensions were obtained. Two non-linear statistical models (gamma weighted model and cubic polynomial model) were tested on the data and the best fitting model was used to calculate z-scores of these cardiac chamber measures. The reference ranges are presented on scatter plots against BSA.

Results

Normative data for the following cardiac measures were obtained and z-scores calculated: right ventricular diameter at end diastole (RVEDD); left ventricular diameter at end diastole (LVEDD) and systole (LVESD); interventricular septal wall thickness at end diastole (IVSd) and systole (IVSs); left ventricular posterior wall thickness at end diastole (LVPWd) and systole (LVPWs); left atrium diameter at end systole (LA) and tricuspid annular plane systolic excursion (TAPSE). Girls had higher values for BMI and heart rate than boys (p = 0.048 and p = 0.001, respectively). Mean interventricular septal and left ventricular posterior walls thickness was higher than published normal values in predominantly Caucasian populations.

Conclusion

These are the first echocardiographic reference ranges for children from sub Saharan Africa and will allow accurate assessment of cardiac dimensions in clinical practice.

Impact of Nutritional Status on Cognition in Institutionalized Orphans: A Pilot Study

INTRODUCTION

Proper nutrition is critical for maximizing brain function and enhancing learning. There is accumulating evidence that early malnutrition, marked by stunting, is associated with long-term deficits in cognitive and academic performance, even when social and psychological differences are controlled. All over the world, children living without permanent parental care are at a heightened risk for under-nutrition, putting their health and development in great jeopardy.

AIM

To assess the nutritional and cognitive status in institutionalized orphans which might help to formulate effective interventions for improving the nutritional status of vulnerable children in future.

MATERIALS AND METHODS

This cross-sectional, study included 70 children (35 orphans and 35 non-orphans). Their anthropometric measurements (height, weight, and BMI) were measured and cognition was assessed using subsets of Wechsler Intelligence Scale for Children-Revised (WISC-R): Block design and Digit span. The data obtained was subjected to descriptive statistical analysis.

RESULTS

18.57% (13) of children had stunting, 15.71% (11) had wasting, 22.86% (16) were underweight, and 17.14% (12) showed thinness. Mean±SD of Block design in non-orphans was significantly higher compared to orphans (p-value 0·05). Mean±SD of Digit span in non-orphans was significantly higher compared to orphans (p-value 0·000). For Block design, there was moderate positive correlation with nutritional status based on Z-scores (p-value <0·05). Digit span also showed moderate positive correlation (p-value <0·05).

CONCLUSION

The results of our study indicate that children in orphanages have high rates of both malnutrition and cognitive delay compared to the non-orphans and there was a direct correlation between both the variables. If orphanages are here to stay as a last resort for children deprived of a family there is an urgent need to improve the institutional environment in order to foster the development of millions of children in orphanages around the world.

Superparamagnetic nanoparticle-enhanced MRI of Alzheimer's disease plaques and activated microglia in 3X transgenic mouse brains: Contrast optimization

PURPOSE

To optimize magnetic resonance imaging (MRI) of antibody-conjugated superparamagnetic nanoparticles for detecting amyloid-β plaques and activated microglia in a 3X transgenic mouse model of Alzheimer's disease.

MATERIALS AND METHODS

Ten 3X Tg mice were fed either chow or chow containing 100 ppm resveratrol. Four brains, selected from animals injected with either anti-amyloid targeted superparamagnetic iron oxide nanoparticles, or anti-Iba-1-conjugated FePt-nanoparticles, were excised, fixed with formalin, and placed in Fomblin for ex vivo MRI (11.7T) using multislice-multiecho, multiple gradient echo, rapid acquisition with relaxation enhancement, and susceptibility-weighted imaging (SWI). Aβ plaques and areas of neuroinflammation appeared as hypointense regions whose number, location, and Z-score were measured as a function of sequence type and echo time.

RESULTS

The MR contrast was due to the shortening of the transverse relaxation time of the plaque-adjacent tissue water. A theoretical analysis of this effect showed that the echo time was the primary determinant of plaque contrast and was used to optimize Z-scores. The Z-scores of the detected lesions varied from 21 to 34 as the echo times varied from 4 to 25 msec, with SWI providing the highest Z-score and number of detected lesions. Computation of the entire plaque and activated microglial distributions in 3D showed that resveratrol treatment led to a reduction of ∼24-fold of Aβ plaque density and ∼4-fold in microglial activation.

CONCLUSION

Optimized MRI of antibody-conjugated superparamagnetic nanoparticles served to reveal the 3D distributions of both Aβ plaques and activated microglia and to measure the effects of drug treatments in this 3X Tg model.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:574-588.

Reference values for spirometry - report from the Obstructive Lung Disease in Northern Sweden studies

BACKGROUND

Abnormal lung function is commonly identified by comparing observed spirometric values to corresponding reference values. It is recommended that such reference values for spirometry are evaluated and updated frequently. The aim of this study was to estimate new reference values for Swedish adults by fitting a multivariable regression model to a healthy non-smoking general population sample from northern Sweden. Further aims were to evaluate the external validity of the obtained reference values on a contemporary sample from south-western Sweden, and to compare them to the Global Lung Function Initiative (GLI) reference values.

METHOD

Sex-specific multivariable linear regression models were fitted to the spirometric data of n=501 healthy non-smoking adults aged 22-91 years, with age and height as predictors. The models were extended to allow the scatter around the outcome variable to depend on age, and age-dependent spline functions were incorporated into the models to provide a smooth fit over the entire age range. Mean values and lower limits of normal, defined as the lower 5th percentiles, were derived.

RESULT

This modelling approach resulted in unbiased estimates of the spirometric outcomes, and the obtained estimates were appropriate not only for the northern Sweden sample but also for the south-western Sweden sample. On average, the GLI reference values for forced expiratory volume in one second (FEV1) and, in particular, forced expiratory vital capacity (FVC) were lower than both the observed values and the new reference values, but higher for the FEV1/FVC ratio.

CONCLUSION

The evaluation based on the sample of healthy non-smokers from northern Sweden show that the Obstructive Lung Disease in Northern Sweden reference values are valid. Furthermore, the evaluation based on the south-western Sweden sample indicates a high external validity. The comparison with GLI brought further evidence to the consensus that, when available, appropriate local population-specific reference values may be preferred.

Respiratory symptoms, spirometric respiratory impairment, and respiratory disease in middle-aged and older persons

OBJECTIVES

To evaluate whether a novel definition of spirometric respiratory impairment from the Global Lung Initiative (GLI) is strongly associated with respiratory symptoms and, in turn, frequently establishes symptomatic respiratory disease.

DESIGN

Cross-sectional.

SETTING

Third National Health and Nutrition Examination Survey.

PARTICIPANTS

Community-dwelling individuals aged 40 to 80 (N = 7,115).

MEASUREMENTS

GLI-defined spirometric respiratory impairment (airflow obstruction and restrictive pattern), dyspnea on exertion (DOE), chronic bronchitis (CB), and wheezing.

RESULTS

Prevalence rates were 12.7% for airflow obstruction, 6.2% for restrictive pattern, 28.6% for DOE, 12.6% for CB, and 12.9% for wheezing. Airflow obstruction was associated with DOE (adjusted odds ratio (aOR) = 1.69, 95% confidence interval (CI) = 1.42-2.02), CB (aOR = 1.92, 95% CI = 1.62-2.29), and wheezing (aOR = 2.50, 95% CI = 2.08-3.00), and restrictive pattern was associated with DOE (aOR = 1.75, 95% CI = 1.36-2.25), CB (aOR = 1.39, 95% CI = 1.08-1.78), and wheezing (aOR = 1.53, 95% CI = 1.15-2.04). Nonetheless, among participants who had airflow obstruction and restrictive pattern, only a minority had DOE (38.6% and 45.5%), CB (23.3% and 15.9%), and wheezing (24.4% and 19.1%), yielding a positive predictive value (PPV) of only 53% for any respiratory symptom in the setting of any spirometric respiratory impairment. In addition, most participants who had DOE (73.0%), CB (67.8%), and wheezing (66.8%) did not have airflow obstruction or restrictive pattern, yielding a PPV of only 26% for any spirometric respiratory impairment in the setting of any respiratory symptom. The results differed only modestly when stratified according to age (40-64 vs 65-80).

CONCLUSION

GLI-defined spirometric respiratory impairment increased the likelihood of respiratory symptoms but was nonetheless a poor predictor of respiratory symptoms. Similarly, respiratory symptoms were poor predictors of GLI-defined spirometric respiratory impairment. Hence, a comprehensive assessment is needed when evaluating respiratory symptoms, even in the presence of spirometric respiratory impairment.

Dual-energy X-ray absorptiometry diagnostic discordance between Z-scores and T-scores in a young Iranian population

BACKGROUND

Dual-energy X-ray Absorptiometry (DXA) is considered the gold standard for non-invasive measurement of bone mass. T-scores and Z-scores are used to present the results of bone mass. The present study was designed to evaluate the discordance between T-scores and Z-scores calculated at a same level and its relation with age, gender and body mass index (BMI) in a representative sample of normal population.

METHODS

This cross-sectional study was conducted as a part of a comprehensive survey, Iranian Multicenter Osteoporosis Study (IMOS), designed to assess bone health among healthy adults. Each individual underwent both L1-L4 antero-posterior lumbar spine and hip DXA scan. The difference between the T- and Z-scores measured at each of the four skeletal sites was then calculated.

RESULTS

A -1.21 to 1.21 point difference was noted in the Z- and T- scores measured at each site. While the difference between the T-and Z-scores was less than 0.5 SD in most of the cases, the difference was higher than 1 SD in about 5% of the subjects.

CONCLUSION

Standardization of Z-score definition and calculation techniques as well as developing an ethnicity-matched reference population is needed to improve the reliability of DXA-generated Z-scores.

The effect of low magnitude mechanical stimulation (LMMS) on bone density in patients with Rett syndrome: a pilot and feasibility study

PURPOSE

Low magnitude mechanical stimulation (LMMS) has been used successfully to promote bone formation in certain patient populations. This study evaluated the feasibility and effectiveness of LMMS on improving bone mineral density (BMD) in patients with Rett syndrome.

METHODS

A 12-month crossover pilot study design of 6 months of intervention with LMMS and 6 months without was studied in 14 subjects divided in two subgroups. BMD was assessed using Dual Energy X-ray Absorptiometry (DXA). The levels of 25-hydroxy vitamin D (25OHD), Parathyroid Hormone (PTH), Insulin-Like Growth Factor 1 (IGF-1), and circulating markers of bone resorption (NTx) were analyzed in blood samples. Health questionnaires and diet logs were obtained at 0, 6, and 12 months.

RESULTS

Of the 11 subjects who completed the protocol, 9 had an adherence of > 65% and showed an increase in spine BMD Z-scores from the intervention (Z: -2.51) compared to non-intervention period (Z: -2.27) of 0.23 SD (p=0.048). Following intervention, favorable trends were also observed for IGF-1 (p=0.06) and right distal femur BMD Z-scores (p=0.07).

CONCLUSIONS

These preliminary results are promising for a larger, placebo-controlled randomized study of subjects with Rett syndrome.