Geometric method for measuring body surface area: a height-weight formula validated in infants, children, and adults

Improving accuracy of SUV estimates in paediatric oncology: Recommending against the use of body weight corrected SUV in [18F]FDG PET

PURPOSE

Few studies have assessed body weight dependency of Standardised Uptake Value (SUV) formulations in paediatric patients. This study aims to compare different SUV formulations measured in reference tissues in paediatric patients and determine which correction method shows the least dependency on body weight.

METHODS

A single-centre, retrospective analysis of [18F]FDG PET/CT scans was performed. SUV measurements were taken from liver and blood pool using EARL1 reconstructions. SUV measurements were corrected for body weight (SUVBW), lean body mass (LBM) according to James (SUVLBMJames) and Janmahasatian (SUVLBMJanma), and body surface area (BSA) according to DuBois (SUVBSADuBois) and Haycock (SUVBSAHaycock). The coefficient of determination (r2) was used to assess the correlation between SUV and body weight.

RESULTS

In total, 461 scans were analysed, including 185 (40%) from female patients. The median age of patients was 12 years (IQR 8-15.5 years). SUVBW exhibited the strongest correlation with body weight, with r2 = 0.65 for the liver and r2 = 0.50 for the blood pool. In contrast, SUVBSADuBois and SUVBSAHaycock had the weakest correlation, with r2 = 0.09 for the liver and r2 = 0.06 for the blood pool. SUVLBMJames and SUVLBMJanma had moderate correlations, with r2 = 0.51 and r2 = 0.44 for the liver and blood pool, respectively, and r2 = 0.47 and r2 = 0.42, respectively.

CONCLUSION

In paediatric [18F]FDG PET/CT scans, SUVBW should be avoided due to elevating values in heavier patients. SUVBSA presents the least dependency on body weight and provides the most consistent assessments of metabolic activity.

Stunted African toddlers digest and obtain energy from energy-dense thick sorghum porridge

BACKGROUND/OBJECTIVES

Increasing the energy density of porridges could help meet the needs of moderately malnourished, stunted children. However, it is not clear whether stunted toddlers can adequately digest and obtain energy from energy-dense porridges with thick texture. A clinical study was conducted in Bamako, Mali, using 13C-labeled substrates and serial breath sampling to determine whether stunted toddlers differed from healthy toddlers in their capacity to digest thick and thin sorghum porridges.

SUBJECTS/METHODS

Experimental porridges, including a traditional porridge (control), a starch-enriched calorie-dense thick porridge, and an α-amylase-thinned calorie-dense porridge, were fed to stunted (n = 24) and healthy (n = 24) 18-30-month toddlers. Breath test results were expressed as Percent Dose Recovery and curve fit using the Weibull function to determine the kinetics of starch digestion.

RESULTS

The stunted and healthy toddlers were able to digest and oxidize the starch from traditional porridge equally well, with no statistically significant differences between the kinetic parameters of the two groups. After consumption of thickened porridge, healthy toddlers had slightly faster starch digestion kinetics with PDR curves rising more rapidly (p < 0.05) and peaking earlier in the postprandial period (p < 0.01) for healthy individuals than for stunted individuals, yet these groups did not have differences in the overall extent of starch digestion, as their final CPDR values were not significantly different. Gastric emptying rate did not differ significantly between the healthy and stunted groups.

CONCLUSION

Overall, we found that thick porridge supplied digestible carbohydrates to stunted and healthy toddlers, as well as thinned calorie-dense porridge.

Prospective study on ultrasonographic measurement of the spinal canal depth in very low birth weight infants

BACKGROUND

Lumbar punctures (LP) in very low birth weight (VLBW) infants often have low success rates. Point-of-care ultrasound (POCUS)-based spinal canal depth (SCD) measurements may provide better outcomes.

AIM

To provide POCUS-based SCD measurement values for VLBW infants using different calculation methods at the L4/5 and L3/4 levels.

METHODS

This prospective observational study involved 31 VLBW infants in the neonatal intensive care unit at Women's Wellness and Research Center, Doha, Qatar, from March 2022 to September 2023. The outcome measures included anterior (ASCD), mid (MSCD) and posterior spinal canal depth (PSCD) measurements. The study compared results from different calculation methods at the L4/5 and L3/4 levels.

RESULTS

A total of 63 ultrasound examinations were performed on 31 infants. The median gestational age was 25.0 weeks (IQR 24-27), with a birth weight of 817.9±170.2 g and a birth height of 31.6±2.8 cm. The MSCD at L4/5 was 7.1±0.5 mm and 6.9±0.5 mm at L3/4, with a mean difference (MD) of 0.20 (95% CI 0.15 to 0.24; p<0.001). The mean SC anteroposterior diameter at L4/5 was 3.8 mm versus 4.2 mm at L3/4 (MD -0.334, 95% CI -0.45 to 0.22; p<0.001). Weight-based and body surface area (BSA) calculations correlated best with MSCD at both levels. The MSCD in millimetres was determined by the equations 2×weight (kg)+6 (R²=0.71) at L4/5 and (R²=0.70) at L3/4 and 25×BSA (m²)+5 (R²=0.71) at L4/5 and (R²=0.73) at L3/4 levels. Moreover, body weight and BSA showed a slightly stronger correlation with ASCD measurements compared with PSCD. All SCD measurements demonstrated a poor linear correlation with body length (cm) and body mass index (kg/m²).

CONCLUSION

This study offers reference data for POCUS-based SCD measurements in VLBW infants, demonstrating that body weight and BSA effectively predict SCD. These findings could enhance the accuracy of LPs in this population when ultrasound guidance is unavailable, supporting personalised care.

The Prognostic Impact of Defect Size Based on Body Surface Area in Omphaloceles

INTRODUCTION

This study addresses the existing gaps in understanding the cases with omphalocele by investigating the potential prognostic impact of the ratio between omphalocele diameter-and -body surface area (BSA), particularly in premature and low birth weight neonates.

MATERIAL AND METHODS

Data retrieved from the hospital files of 25 patients with omphalocele related to their gestational histories, demographics, anthropometric data, comorbidities, defect diameters, and prognoses were retrospectively analyzed. BSA was calculated using the Haycock Formula. Binary logistic regression analysis performed identified mortality-associated factors.

RESULTS

Most (84 %) of the patients with omphalocele, required mechanical ventilation, and the median hospital stay was 19 days. There was no significant correlation between defect diameter or defect diameter-to-BSA ratio and hospital stay. Mortality rate in these patients was 24 %, with a significantly higher mean (±SD) defect diameter-to-BSA ratio in non-survivors compared to survivors (467.9 ± 54.8 vs. 283.1 ± 24.8; p = 0.002). Logistic regression analysis identified the defect diameter-to-BSA ratio as a significant predictor of mortality (p = 0.023, Exp(B) = 1.038, 95 % CI: 1.005-1.072). Other variables, including defect size, cardiac anomalies, and solid organ presence in the sac, were not significant predictors.

CONCLUSION

This study underscores the superior prognostic value of the defect diameter-to-BSA ratio for omphalocele patients, surpassing conventional markers such as defect diameter, cardiac anomalies, and the presence of solid organs in the sac.

The Evaluation of Significance of Uncoupling Protein Genes UCP1, UCP2, UCP3, UCP4, UCP5, and UCP6 in Human Adaptation to Cold Climates

Six isoforms of uncoupling proteins (UCPs) exist, spanning from UCP1 to UCP6. A precise physiological function has only been established for UCP1, which is involved in non-shivering thermogenesis, but the functions of other UCPs are still not fully defined. Therefore, the purpose of the present study is to search for indications of the involvement of nine polymorphic variants of UCP1-6 genes in human adaptation to cold climates using four criteria: (1) the presence of associations of polymorphic variants of UCP genes with levels of thyroid-stimulating hormone, free triiodothyronine, and free thyroxine; (2) the presence of associations of polymorphic variants of UCP genes with changes in thyroid homeostasis (SPINA); (3) the presence of associations of polymorphic variants of UCP genes with body surface area; (4) the presence of signals of directional selection to cold climate for polymorphic variants of UCP genes. As a result of the evaluation, the highest scores for cold adaptation traits were recorded for polymorphic variants rs3811787 of the UCP1 gene and rs1800849 of the UCP3 gene. We suggest that the results obtained indicate the importance of uncoupling proteins UCP1 and UCP3 in human adaptation to cold through processes of non-shivering and shivering thermogenesis.

Reliability of hemodynamic parameters measured by bioimpedance cardiography at different intensities during incremental exercise testing

Background

Bioimpedance cardiography offers a non-invasive and time-efficient method to measure hemodynamic parameters. Previous studies only investigated its reliability under steady-state conditions and at maximum load but not at ventilatory thresholds (VTs). This is the first study that assesses the reliability of measured hemodynamic parameters at different exercise stages during cardiopulmonary exercise testing (CPET) using prespecified strict criteria to assess reliability.

Methods

Data from 31 healthy, well-trained adults were analyzed. Each participant completed two CPETs, both following the same ramp protocol, with a 7-day interval between them. Hemodynamic parameters were measured with the PhysioFlow® (Manatec Biomedical, Poissy, France) at characteristic phases and thresholds [VT1, VT2, and peak oxygen uptake (V̇O2peak)]. To ensure comparability, the wattage (power) corresponding to the thresholds in Test 1 (PVT1, PVT2, and PV̇O2peak) was used for Test 2.

Results

Heart rate, stroke volume, and cardiac output demonstrated good reliability on a group level (mean intraclass correlation >0.75) at both thresholds (0.91, 0.80, and 0.77 at PVT1; 0.92, 0.80, and 0.77 at PVT2) and at PV̇O2peak (0.93, 0.82, and 0.80). For stroke volume at PV̇O2peak, both individual differences (-39.0 to 36.9 mL for the women and -39.9 to 45.2 mL for the men) and mean detectable change (17.5 mL) were larger than the a priori defined acceptable ranges of agreement (-3.6 to 3.8 mL for the women and -4.5 to 3.3 mL for the men).

Conclusion

The PhysioFlow® reliably measures heart rate, stroke volume, and cardiac output during CPET on a group level. However, as shown by the Bland-Altman plots, the reliability is too low to be used for individual comparisons.

Differences in appetite, food intake, and gastric emptying responses to protein intake by older adults varying in level of physical activity: A randomised controlled trial

Older adults are encouraged to increase their protein intake and engage in more physical activity to preserve muscle mass. However, since protein is considered the most satiating macronutrient, this advice might lead to a decrease in overall energy consumption. Physical activity is also recommended to older adults to enhance appetite, as it has been shown to help regulate appetite in younger adults, yet there is limited evidence to support this in older populations. The objective of this study was to investigate the impact of physical activity and protein on food intake, perceived appetite, and gastric emptying in older adults. Nineteen active and 19 less active older adults completed a single-blind, randomised, crossover trial involving two test days at home. Participants received a standard breakfast, followed by an isovolumetric (250 ml) and isocaloric (∼300 kcal) high- or low-protein preload milkshake (57% versus 17% energy as protein) matched for sensory properties. Three hours after the preload, participants were offered an ad libitum meal. Food intake was weighed, perceived appetite was measured by 100 mm visual analogue scales, and gastric emptying via the 13C-octanoic acid breath test. Higher protein intake did not affect subsequent energy intake or appetite ratings in both active and less active groups. Gastric emptying half time was longer following the high-protein milkshake compared to the low-protein milkshake. The active group had a lower perceived appetite, but faster gastric emptying time compared to the less active group. In conclusion, while higher protein intake slows gastric emptying, it did not reduce appetite or subsequent food intake in older adults, regardless of physical activity level. Additionally, being physically active suppresses perceived appetite and accelerates gastric emptying without affecting food intake.

Hemodynamic Analysis in Aortic Dilatation after Arterial Switch Operation for Patients with Transposition of Great Arteries Using Computational Fluid Dynamics

After an arterial switch operation for complete transposition of the great arteries, neo-aortic root dilatation occurs, with unclear hemodynamic effects. This study analyzes three groups (severe dilation, mild dilation, and normal) using computational fluid dynamics (CFD) on cardiac CT scans. Aortic arch angles in severe (median 72.3, range: 68.5-77.2) and mild dilation (76.6, 71.1-85.2) groups are significantly smaller than the normal group (97.3, 87.4-99.0). In the normal and mild dilatation groups, Wall Shear Stress (WSS) exhibits a consistent pattern: it is lowest at the aortic root, gradually increases until just before the bend in the aortic arch, peaks, and then subsequently decreases. However, severe dilation shows disrupted WSS patterns, notably lower in the distal ascending aorta, attributed to local recirculation. This unique WSS pattern observed in severely dilated patients, especially in the transverse aorta. CFD plays an essential role in comprehensively studying the pathophysiology underlying aortic dilation in this population.

Trough value prediction using umbilical blood cystatin C value during tobramycin administration

BACKGROUND

Therapeutic monitoring is recommended for aminoglycoside drugs, which are often used in neonatal care. In this study, we examined whether it is possible to estimate the trough value after administration using serum creatinine (Cr) and serum cystatin C (CysC) values of umbilical cord artery blood in infants, which can be measured without increasing risks due to invasive tests.

METHODS

Subjects included infants who were hospitalized between March 2022 and March 2023 and treated with tobramycin (TOB) from 0 days old. In addition to cord blood Cr and CysC, TOB blood concentration (trough value) was measured at 3 days. The correlation coefficient (r) between serum Cr and CysC values and TOB trough value was calculated.

RESULTS

Sixteen cases were included in the study. Cord blood Cr and CysC values were divided by gestational week (GW), birth weight (BW), and body surface area (BSA), respectively, and the correlations with TOB trough values were determined. Cord blood CysC/GW/BSA showed a strong correlation with TOB trough value (r = 0.77). The receiver operating characteristic curve for the relationship between cord blood CysC/GW/BSA and TOB trough values ≥1 mg/mL revealed a cut-off value of 0.29 (area under the curve: 0.927, sensitivity: 1.00, specificity: 0.75).

CONCLUSION

Umbilical cord blood CysC/GW/BSA values were strongly correlated with TOB trough values. Cord blood samples can be used to estimate trough values before drug administration without increasing the risk to infants associated with invasive tests, enabling determination of the dosage that will not cause nephrotoxicity.

Postexercise Dietary Leucine Retention for Whole-Body Anabolism Is Greater With Whey Protein Isolate and Fish-Derived Protein Hydrolysate Than Nonessential Amino Acids in Trained Young Men

Marine-derived proteins, such as blue whiting-derived protein hydrolysates (BWPH), represent high-quality sources of dietary protein, but their ability to support postexercise anabolism is not established. The impact of BWPH on whole-body anabolism was compared with an isonitrogenous whey protein isolate (WPI) and nonessential amino acid (NEAA) control in 10 trained young males (31 ± 4 years) who, on three separate visits, performed a session of whole-body resistance exercise and then consumed, in randomized crossover fashion, BWPH, WPI, or NEAA (0.33 g/kg; 19, 33, and 0 mg/kg leucine, respectively) with L-[1-13C]leucine. Breath, blood, and urine samples were collected for 6-hr postprandial to assess dietary leucine oxidation, amino acid (AA) concentrations, and 3-methylhistidine: creatinine ratio. Peak and area under the curve concentrations for leucine, branched-chain amino acids, and essential amino acids were greater in WPI compared with BWPH (all p < .05) but with no differences in time to peak concentration. Total oxidation reflected leucine intake (WPI > BWPH > NEAA; p < .01), whereas relative oxidation was greater (p < .01) in WPI (28.6 ± 3.6%) compared with NEAA (21.3 ± 4.2%), but not BWPH (28.6 ± 8.8%). Leucine retention, a proxy for whole-body protein synthesis, was greater in WPI (185.6 ± 9.5 μmol/kg) compared with BWPH (109.3 ± 14.1 μmol/kg) and NEAA (5.74 ± 0.30 μmol/kg; both p < .01), with BWPH being greater than NEAA (p < .01). Urinary 3-methylhistidine: creatinine ratio did not differ between conditions. Both WPI and BWPH produced essential aminoacidemia and supported whole-body anabolism after resistance exercise, but a higher intake of BWPH to better approximate the leucine and EAA content of WPI may be needed to produce an equivalent anabolic response.

The role of vitamin D metabolism in regulating bone turnover in adolescents with perinatally-acquired HIV in Southern Africa: a cross-sectional study in Zimbabwe and Zambia

Vitamin D dysregulation can occur in people living with HIV, disrupting calcium homeostasis, and bone turnover. We aimed to investigate the potential mechanisms by which vitamin D regulates bone turnover in adolescents living with perinatally-acquired HIV (ALWH) in Southern Africa. A pre-planned secondary analysis was performed of baseline data from the vitamin D for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology trial (PACTR20200989766029) which enrolled ALWH (11-19 yr) taking antiretroviral therapy for ≥6 mo, and recorded socio-demographic, clinical and dietary data. After over-night fasting, vitamin D metabolites (25(OH)D, 1,25(OH)2D, and 24,25(OH)2D), intact parathyroid hormone (PTH), and bone turnover markers (BTMs) (C-terminal telopeptide of type I collagen (CTX) and procollagen type 1 N-terminal propeptide (P1NP)) were measured. Tandem Mass Spectrometry measured vitamin D metabolites, while intact PTH and BTMs were analyzed by electrochemiluminescence immunoassay. Stratified by 25(OH)D (<75 vs ≥75 nmol/L), associations between standardized concentrations (β = standard deviations) of vitamin D metabolites, intact PTH and BTMs were assessed using structural equations modelling (SEM) adjusted for age, sex, and country (Zimbabwe/Zambia). Among the 842 ALWH enrolled, the median dietary calcium intake was 100 mg (IQR: 55-145). The SEM showed PTH was positively associated (β: 0.21; 95% CI, 0.1, 0.32) with 1,25(OH)2D, only when 25(OH)D was <75 vs ≥75 nmol/L (β: 0.23; 95%CI, -0.13, 0.59), with evidence of an interaction (β: -0.11; 95%CI, -0.20, -0.02). A positive relationship between 25(OH)D and 24,25(OH)2D was seen irrespective of 25(OH)D concentration. 24,25(OH)2D was inversely related to BTMs, particularly when 25(OH)D was <75 nmol/L (CTX: β: -0.15; 95% CI, -0.24, -0.06 and P1NP: β: -0.14; 95%CI, -0.22, -0.06). There was interaction between dietary calcium and 25(OH)D on PTH (β: -0.15; 95% CI, -0.22, -0.07) suggesting an interaction between low 25(OH)D and low dietary calcium which increases PTH. In conclusion, associations between 25(OH)D, PTH, 1,25(OH)2D, and BTMs in ALWH appear dependent upon 25(OH)D concentrations <75 nmol/L and calcium intake. A novel, potentially causal pathway between 25(OH)D, 24,25(OH)2D, and BTMs was seen. Findings enhance understanding of vitamin D metabolism in people living with HIV.

Comparison of different eGFR formulas to measured glomerular filtration rate using iohexol in children and adolescents with mild chronic kidney disease

Estimated glomerular filtration rate (eGFR) based on different formulas is commonly used as a bedside tool to assess kidney function in children and young adults. The purpose of this study was to perform a measurement of glomerular filtration rate (mGFR) in children with chronic kidney disease (CKD) with a standard 5-point protocol using iohexol clearance and compare it to a simplified protocol for mGFR determination and to some of the most commonly used eGFR formulas. A 5-point standard protocol using iohexol clearance was used for determination of mGFR in 50 children with mild stages of CKD. The result was compared to 2- and 3-point sampling protocol as well as with some standard children eGFR formulas. We calculated the prediction performance for eGFR formulas to distinguish CKD1 and CKD 2 stages, formulas' accuracy, and cutoff values. Data were prospectively collected. All eGFR formulas exhibited a statistically significant positive correlation with mGFR. The best correlation was found with CKID2012 eGFR formula and with cystatin C-based eGFR formulas. The correlation between standard and simplified protocols for mGFR determination was also strong, while creatinine clearance did not prove to be a reliable method for estimating GFR. The error distribution with simplified protocols was not dispersed. The prediction value was strong for CKID2012 and bedside Schwartz formula. Conclusion: Fewer sampling points can be safely used for measuring GFR in children. eGFR formulas that are not based solely on creatinine should be considered more often in GFR estimation. What is Known? • Iohexol clearance is an established method of measuring GFR in children and adolescents using different protocols. • Estimating GFR in children and adolescents is troublesome and is done using different formulas with anthropometric and biochemical markers in children and adolescents. What is New? • Iohexol measurement with two or three blood withdrawals can reliably distinguish between CKD1 and CKD2 patients. • eGFR formulas have moderate reliability to predict distinguish between CKD1 and CKD2 patients, of which CKID2012 and bedside Schwartz formula were the most accurate in our study.

Comparison of methods to normalize urine output in critically ill patients: a multicenter cohort study

BACKGROUND

Oliguria diagnosis includes the normalization of urine output (UO) by body weight. However, the rational and the method to apply to normalize UO to body weight are unclear. We aimed to explore the impact of the method applied to normalize UO on oliguria incidence and association with outcomes.

METHODS

We included all adult patients admitted to a Swiss (derivation cohort) and a US (MIMIC-IV database, validation cohort) ICU, except those on maintenance hemodialysis, who declined consent or had < 6 consecutive UO measurements. Among a panel of candidate variables (ideal body weight, body mass index, body surface area and adjusted body weight), we identified the best predictor for UO (i.e. the variable that was most closely associated with mean UO during ICU stay). We then compared oliguria incidence and association with 90-day mortality and acute kidney disease (AKD) at hospital discharge, according to whether UO was normalized by actual body weight (ABW) or the identified best UO predictor.

RESULTS

The derivation and validation cohorts included respectively 15 322 and 28 610 patients. Those in the validation cohort were heavier (mean ABW 81 versus 75 kg) older (65 versus 62 years) and had a lower SAPS-II score (38 versus 43). The best UO predictor was ideal body weight (IBW). Oliguria incidence increased almost linearly across weight categories with ABW normalization but remained constant with IBW normalization. Using IBW for UO normalization rather than ABW improved the association between oliguria and 90-day mortality and AKD. It increased the proportion of patients correctly classified from 37.6 to 48.3% (mortality) and from 37.8 to 47% (AKD). All findings persisted after correction for sex and SAPS-II score and were confirmed in sensitivity analyses.

CONCLUSION

UO normalization by IBW lead to a stable incidence of oliguria across categories of weight and improved the association between oliguria and outcomes. IBW should be preferred to normalize UO in critically ill patients.

Body weight and body surface area of adult patients with selected cancers: An Italian multicenter study

Although body weight (BW) and body surface area (BSA) are utilized to establish the appropriate dosage of anticancer drugs, their distribution in cancer patients is poorly studied, making it challenging to predict the amount of drug use and related costs of BW or BAS-dosed regimens. This study investigates the distribution of BW and BSA in adults with selected cancers who initiated systemic anticancer treatment in the eastern Emilia-Romagna region hospitals between 2011 and 2021. BW and BSA were collected at the first cycle of each new treatment line, with multiple measurements for patients receiving various treatments or treating for other primary malignancies. Results were grouped by sex, tumor site and treatment setting, and the normal distribution hypothesis was tested for each group. Both linear regression model and quantile regression at the 50th, 25th and 75th percentiles were run to explore the factors influencing BSA. The analysis included 20,634 treatment lines and the corresponding BW and BSA measures from a sample of 13,036 patients. The average BW was 68.05kg (64.20kg for females and 75.07kg for males) and the average BSA was 1.76m2 (1.66m2 for females and 1.87m2 for males). In women, the highest BW was in breast and colon groups, while in men, it was associated with prostate and rectum cancers. The model indicated significant association between BSA, age, sex and tumor localization. Notably, stomach and lung cancers were linked to lower BSA for both sexes (for females -0.081 and -0.041m2 respectively compared to those with breast cancer). Advanced settings were related to lower BSA than neoadjuvant treatment, especially for stomach cancer patients, who experienced a weight loss of 3 to 6kg as therapy progressed. The regression models for predicting BSA can assist regulatory bodies in determining reimbursement for new chemotherapy drugs and help hospitals forecast drug utilization and expenditure more accurately.

Effect of lactic acid-rich sourdough bread on appetite regulation: A randomized, double-blind controlled trial

Sourdough bread consumption has been associated with improved glucose and appetite regulation thanks to the presence of organic acids produced during fermentation of the flour-water mixture. We investigated the effects of whole meal sourdough bread (WSB) rich in lactic acid on energy intake, satiety, gastric emptying, glucose, and C-peptide response compared to whole meal yeast bread (WYB). Forty-four normal-weight participants (age: 30 ± 10 y; BMI: 23 ± 2 kg/m2) participated in this double-blind, randomized cross-over trial, consisting of two study visits separated by one week. During each study visit, gastric emptying, subjective appetite, glucose, and C-peptide concentrations were measured at regular time intervals over a 4-h period. After 4 h, ad-libitum energy intake was assessed. Despite no effect of bread type on ad-libitum energy intake at the subsequent meal (p = 0.068), WSB led to lower hunger (p < 0.001), higher fullness (p < 0.001), lower desire to eat (p < 0.001), and lower prospective food consumption (p < 0.001) compared to WYB. WSB had a higher gastric half-emptying time (p = 0.002), lower glucose response between 15 and 30 min (p < 0.05) after bread consumption, and lower C-peptide response between 15 and 90 min (p < 0.05) after bread consumption, compared to WYB. These findings suggest that the consumption of WSB, rich in lactic acid, acutely enhanced satiety and improved the postprandial metabolic response. However, these effects did not result in reduced ad-libitum energy intake.

Fingerprint Sweat Pore Density in Patients with Oligodontia: A Controlled Clinical Trial

Background/Objectives: There is a lack of evidence for the relationship between sweat pores and tooth agenesis. The aim of this study was to compare sweat pore density on fingertips between a group of patients with oligodontia and a control group without tooth agenesis. Methods: This parallel-group controlled clinical trial included 28 patients. Fourteen patients (f/m 9/5; mean age 13.5 ± 3.5 years) with ≥6 congenitally missing permanent teeth, excluding third molars (M3), were enrolled in the study group. The matched control group consisted of 14 patients (f/m 9/5; mean age 12.8 ± 1.8 years) without tooth agenesis. Impressions of 168 fingertips (left and right index, middle, and ring fingers) of the participating subjects were taken and examined using a scanning electron microscope with a 5.85 mm × 4.29 mm region of interest at the center of the fingertip. The primary outcome was the pore-to-pore distance (μm) on a dermal ridge, and the secondary outcome was the number of sweat pores per cm2, while pore numbers were adjusted for individual body surface area (BSA). Results: There were no statistically significant differences in age, height, weight, and BSA between the groups. The study group had 11.07 ± 4.03 missing teeth, excluding M3. There was a statistically significant difference (p = 0.006) in the distance between adjacent pores on a dermal ridge between the study and control groups (354.89 ±32.41 μm vs. 340.31 ±39.04 μm). The unadjusted pore numbers showed a statistically significant difference between the groups, but after adjustment for BSA, this difference was no longer present. Conclusions: Patients with oligodontia differed from subjects without tooth agenesis in the distance between two adjacent sweat pores on a dermal ridge. However, the differences were small and of limited clinical significance. Increased pore distance appears to be a better predictor of oligodontia/ectodermal dysplasia than pore number.

Identification of vancomycin exposure target in neonates: how much is enough?

OBJECTIVES

Vancomycin is commonly used in neonates with the same pharmacokinetics/pharmacodynamics (PK/PD) target as adults. However, no evidence supports this practice, and the association between trough concentrations and treatment outcomes has been widely questioned. This study aimed to identify the optimal PK/PD predictor and assess the correlation between AUC/MIC, trough concentration and the vancomycin efficacy in neonates.

METHODS

This study retrospectively collected neonates who used vancomycin and constructed a population pharmacokinetic (PPK) model to estimate the AUC. Logistic analyses were used to identify the variables related to efficacy. Classification and regression tree analysis was used to explore thresholds. The correlation between trough concentration and AUC/MIC on the first day was analysed using a linear regression model.

RESULTS

PPK modelling involved 131 neonates. Postmenstrual age and current weight were included in the covariate analysis. Forty-eight patients were included in the efficacy analysis, 13 of whom were infected with MRSA. The best-performance PK/PD target for efficacy was AUC0-24h/MIC ≥ 331. The trough concentration was correlated with AUC0-24h/MIC (r2 = 0.32), but individual differences existed. AUC0-24h/MIC ranged up to 2.5-fold for a given trough concentration.

CONCLUSIONS

AUC0-24h/MIC ≥ 331 was the optimal target of vancomycin efficacy in neonates. The trough concentration was not a reliable predictor of efficacy and AUC0-24h/MIC. AUC-guided dosage adjustments are more valuable in clinical applications.

Total osteocalcin levels are independently associated with worse testicular function and a higher degree of hypothalamic-pituitary-gonadal axis activation in Klinefelter syndrome

PURPOSE

The role of osteocalcin (OCN) in pubertal development, male hypogonadism, and the effect of testosterone (Te) replacement therapy (TRT) remains unclear. We aimed to investigate the total OCN (tOCN) concentrations in male patients with Klinefelter syndrome (KS), a model of adult hypergonadotropic hypogonadism.

METHODS

This retrospective longitudinal study investigated 254 male patients with KS (47,XXY) between 2007 and 2021 at an academic referral center, categorized as (1) prepubertal, (2) pubertal, and (3) adults. All prepubertal patients were Te-naïve. Adult patients were subcategorized as (1) eugonadal, (2) hypogonadal, and (3) receiving TRT. We also analyzed 18 adult patients with available tOCN levels before and 3 months after TRT commencement.

RESULTS

The tOCN levels varied throughout the lifespan according to pubertal status, were highest in eugonadal and significantly lower in TRT subjects, correlated with both LH (p = 0.017) and FSH levels (p = 0.004) in adults, and significantly declined after 3 months of TRT (p = 0.006) in the adult KS cohort. HPG-axis hormones levels demonstrated no correlation in prepubertal boys. Adjustment for age and body mass index confirmed previous results and revealed significant inverse correlations with total Te (p = 0.004), calculated free Te (p = 0.016), the Te/LH (p = 0.010), and calculated free Te/LH ratios (p = 0.031).

CONCLUSION

In KS, a model of male hypergonadotropic hypogonadism, tOCN levels were not associated with gonadal function during normal prepuberty and pubertal development but were associated with worse testicular function and a higher degree of HPG stimulation in adults. TRT acutely reduced tOCN levels in adults.

Surgical outcome of the borderline hypoplastic left ventricle: impact of the left ventricle rehabilitation strategy

OBJECTIVE

This study aims to assess the surgical outcome of borderline hypoplastic left ventricle before and after the induction of the left ventricle rehabilitation strategy.

METHODS

A retrospective review investigated patients with borderline hypoplastic left ventricle who underwent surgical intervention between 2012 and 2022. The patient cohort was stratified into two groups based on the initiation of left ventricle rehabilitation: an early-era group (E group, 2012-2017) and a late-era group (L group, 2018-2022). Left ventricle rehabilitation was defined as palliation combined with other procedures aimed at promoting left ventricular growth such as restriction of atrial septal defect, relief of inflow/outflow obstructive lesions, and resection of endocardial fibroelastosis.

RESULTS

A total of 58 patients were included. Primary diagnosis included 12 hypoplastic left heart syndromes, 11 critical aortic valve stenosis, and others. A total of 9 patients underwent left ventricle rehabilitation, 8 of whom underwent restriction of atrial septal defect. As for clinical outcomes, 9 of 23 patients achieved biventricular repair in the E group, whereas in the L group, 27 of 35 patients achieved biventricular repair (39% vs. 77%, p = 0.004). Mortality did not differ statistically between the two groups (log-rank test p = 0.182). As for the changes after left ventricle rehabilitation, left ventricular growth was observed in 8 of 9 patients. The left ventricular end-diastolic volume index (from 11.4 to 30.1 ml/m2, p = 0.017) and left ventricular apex-to-right ventricular apex ratio (from 86 to 106 %, p = 0.014) significantly increased after left ventricle rehabilitation.

CONCLUSIONS

The introduction of the left ventricle rehabilitation strategy resulted in an increased proportion of patients achieving biventricular repair without a concomitant increase in mortality. Left ventricle rehabilitation was associated with enhanced left ventricular growth and the formation of a well-defined left ventricle apex. Our study underscores the significance of left ventricle rehabilitation strategies facilitating successful biventricular repair. The data suggest establishing restrictive atrial communication may be a key factor in promoting left ventricular growth.

Minute Ventilation/Carbon Dioxide Production Slope Could Predict Short- and Long-Term Prognosis of Patients After Acute Decompensated Heart Failure

(1) Background: Heart failure (HF) leads to functional disability and major cardiovascular events (MACEs). Cardiopulmonary exercise testing (CPET) is the gold standard for assessing aerobic capacity and prognostic stratification. This study aimed to evaluate the predischarge CPET variables in patients with acute decompensated HF and identify the submaximal CPET variables with prognostic value. (2) Methods: A retrospective cohort study was conducted at a tertiary center in Taiwan. Patients surviving their first episode of decompensated HF and undergoing predischarge CPET (February 2017 to January 2023) were analyzed. Follow-up was conducted until a MACE or administrative censoring (up to 5 years). Cox regression identified the significant predictors of MACE. (3) Results: The study included 553, 485, and 267 patients at the 3-month, 1-year, and 5-year follow-ups, respectively. MACE rates were 15.0%, 34.2%, and 50.9%. The VE/VCO2 slope was a significant predictor of MACE at all intervals. A VE/VCO2 slope >38.95 increased the risk of MACE by 2.49-fold at 3 months and 1.81-fold at 1 year (both p < 0.001). A slope > 37.35 increased the 5-year MACE risk by 1.75-fold (p = 0.002). (4) Conclusions: The VE/VCO2 slope is a significant submaximal CPET predictor of MACE in patients post-acute decompensated HF for both short- and long-term outcomes.

The evaluation of kidney function estimation during lifestyle intervention in children with overweight and obesity

BACKGROUND

Children with overweight and obesity are at risk for developing chronic kidney disease (CKD). During lifestyle adjustment, the first step in the treatment of childhood obesity, body proportions are likely to change. The aim of this study was to examine how lifestyle intervention affects creatinine-based kidney function estimation in children with overweight and obesity.

METHODS

This longitudinal lifestyle intervention study included 614 children with overweight and obesity (mean age 12.17 ± 3.28 years, 53.6% female, mean BMI z-score 3.32 ± 0.75). Loss to follow-up was present: 305, 146, 70, 26, and 10 children were included after 1, 2, 3, 4, and 5 (about yearly) follow-up visits, respectively. Serum creatinine (SCr) was rescaled using Q-age and Q-height polynomials.

RESULTS

At baseline, 95-97% of the children had a SCr/Q-height and SCr/Q-age in the normal reference range [0.67-1.33]. SCr/Q significantly increased each (about yearly) follow-up visit, and linear mixed regression analyses demonstrated slopes between 0.01 and 0.04 (corresponding with eGFR FAS reduction of 1.1-4.1 mL/min/1.73 m2) per visit. BMI z-score reduced in both sexes and this reduction was significantly higher in males. No correlation between change in rescaled SCr and BMI z-score reduction could be demonstrated.

CONCLUSIONS

Rescaled serum creatinine (SCr/Q) slightly increases during multidiscipline lifestyle intervention in this cohort of children with overweight and obesity. This effect seems to be independent from change in BMI z-score. Whether this minor decrease in estimated kidney function has clinical consequences in the long term remains to be seen in trials with a longer follow-up period.

CLINICAL TRIAL REGISTRATION

ClinicalTrial.gov; Registration Number: NCT02091544.

The cardiovascular exercise response in children with overweight or obesity measured by cardiovascular magnetic resonance imaging

BACKGROUND

Overweight and obesity are among the main causes of cardiovascular diseases. Exercise testing can aid in the early detection of subtle cardiac dysfunction not present in rest. We hypothesized that the cardiovascular response to exercise is impaired among children with overweight or obesity, characterized by the inability of the cardiovascular system to adapt to exercise by increasing cardiac volumes and blood pressure. We performed a cardiovascular stress test to investigate whether the cardiovascular exercise response is altered in children with overweight and obesity, as compared to children with a normal weight.

SUBJECTS

A subgroup of the Generation R population-based prospective cohort study, consisting of 41 children with overweight or obesity and 166 children with a normal weight with a mean age of 16 years, performed an isometric exercise.

METHODS

Continuous heart rate and blood pressure were measured during rest, exercise and recovery. Cardiovascular magnetic resonance (CMR) measurements were performed during rest and exercise.

RESULTS

Higher BMI was associated with a higher resting systolic and diastolic blood pressure (difference: 0.24 SDS (95% CI 0.10, 0.37) and 0.20 SDS (95% CI 0.06, 0.33)) and lower systolic and diastolic blood pressure increases from rest to peak exercise (-0.11 SDS (95% CI -0.20, -0.03) and -0.07 SDS (95% CI -0.07, -0.01)). BMI was also associated with a slower decrease in systolic and diastolic blood pressure during recovery (p values < 0.05). Higher childhood BMI was associated with lower BSA corrected left ventricular mass, end-diastolic volume and stroke volume (p values < 0.05). There were no associations of childhood BMI with the cardiac response to exercise measured by heart rate and CMR measurements.

CONCLUSION

Childhood BMI is, across the full range, associated with a blunted blood pressure response to static exercise but there were no differences in cardiac response to exercise. Our findings suggest that adiposity may especially affect the vascular exercise reaction without affecting cardiac response.

Successful non-invasive imaging of the coronary artery IMT in pediatric patients with Kawasaki disease using high-resolution echocardiography

Kawasaki Disease (KD) is a multisystemic vasculitis of medium- and small-sized arteries. Abnormal intimal thickening may develop in the involved arterial area after regression of coronary artery aneurysm (CAA). Intimal dysfunction may induce local stenosis or arteriosclerosis in the future. In this case-control study, we investigated 29 consecutive KD patients [20 male, median current age, 7.9 years; median follow-up duration, 5.7 years] and a group of 29 healthy matched controls (CON) [19 male, median current age, 10.8 years]. They were assesed and compared for CAA, LVFS, GCS, GLS, coronary artery (CA) Z scores, carotid intima-media thickness (IMT) and coronary artery IMT by high-resolution transthoracic echocardiography (hrTTE). Coronary artery IMT (caIMT) was significantly higher in patients with a maximal CA Z score > 2.5 in acute KD than in CON: KD caIMT: 0.62 mm [IQR, 0.57-0.72 mm] vs. 0.53 mm [0.51-0.60 mm], p = 0.043. CAAs were found in 15 (51.7%) patients with acute KD. The maximal median LCA Z score in acute KD was 2.57z [IQR, 1.93-3.2z] and in follow-up -0.39z [IQR, -1.25 to -0.36z]. There was no significant difference in carotid IMT between KD patients and CON. Signs of CA intima-media thickening were detected by hrTTE in patients with a maximal CA Z score > 2.5 in acute KD. These data indicate that these patients may be at risk for cardiovascular sequale even in the absence of permanent CA luminal abnormalities. Therefore long-term follow-up of this group of KD patients may be required.

Performance of empirical and model-based classifiers for detecting sucrase-isomaltase inhibition using the13C-sucrose breath test

The13C-sucrose breath test (13C-SBT) has been proposed to estimate sucrase-isomaltase (SIM) activity and is a promising test for SIM deficiency, which can cause gastrointestinal symptoms, and for intestinal mucosal damage caused by gut dysfunction or chemotherapy. We previously showed how various summary measures of the13C-SBT breath curve reflect SIM inhibition. However, it is uncertain how the performance of these classifiers is affected by test duration. We leveraged13C-SBT data from a cross-over study in 16 adults who received 0, 100, and 750 mg of Reducose, an SIM inhibitor. We evaluated the performance of a pharmacokinetic-model-based classifier,ρ, and three empirical classifiers (cumulative percent dose recovered at 90 min (cPDR90), time to 50% dose recovered, and time to peak dose recovery rate), as a function of test duration using receiver operating characteristic (ROC) curves. We also assessed the sensitivity, specificity, and accuracy of consensus classifiers. Test durations of less than 2 h generally failed to accurately predict later breath curve dynamics. The cPDR90 classifier had the highest ROC area-under-the-curve and, by design, was robust to shorter test durations. For detecting mild SIM inhibition,ρhad a higher sensitivity. We recommend13C-SBT tests run for at least a 2 h duration. Although cPDR90 was the classifier with highest accuracy and robustness to test duration in this application, concerns remain about its sensitivity to misspecification of the CO2production rate. More research is needed to assess these classifiers in target populations.

Anticipating Leucovorin Rescue Therapy in Patients with Osteosarcoma through Methotrexate Population Pharmacokinetic Model

Methotrexate (MTX), which presents high inter-individual variability, is part of the Brazilian Osteosarcoma Treatment Group (BOTG) protocol. This work aimed to develop a MTX population pharmacokinetic model (POPPK) for Brazilian children with osteosarcoma (OS) following the BOTG protocol to guide rescue therapy and avoid toxicity. The model was developed in NONMEM 7.4 (Icon®) using retrospective sparse data from MTX therapeutic drug monitoring of children attending a southern Brazilian public reference hospital. Data were described by a two-compartment model using 216 MTX cycles from 32 patients (5-18 y.o.) with OS who received 12 g/m2 dose/cycle. To explain inter-individual and inter-occasion variability in clearance and peripheral volume, covariates from demographic and biochemical data were evaluated. Serum creatinine was a significant covariate of MTX clearance (14.8 L/h), and the body surface area (BSA) was significant for central compartment volume (82.5 L). Inter-compartmental clearance and volume of peripheral compartment were 0.178 L/h and 5.72 L, respectively. The model adequately describes MTX exposure in Brazilian children with OS. Successful simulations were performed to predict MTX concentrations in pediatric patients above five years old with acute kidney injury and anticipate rescue therapy adjustments.

The Z-scores of cardiac indices among healthy children: a systematic review and meta-analysis

BACKGROUND

The application of z-scores in normalizing the cardiac size function and structural dimension will be of immense benefit to the clinician, especially in evaluating children with cardiac anomalies. However, heterogeneity in the obtained z- score results is high, thus a subgroup analysis by region (or continent) to assist healthcare practitioners is necessary.

OBJECTIVES

The review aimed to ascertain the overall mean z-scores for cardiac structures and function.

METHODS

A thorough search of several databases, EMBASE, PubMed/MEDLINE, and Google Scholar was made. Articles published between January 1999 and December 2023 were recruited, of which the last search was done in December 2023. Keywords used in the search were "z-scores", Children; echocardiography; cardiac structures; cardiac function; and body surface area (BSA)". We restricted our search to children. Besides, additional relevant articles were manually searched. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) was used to highlight selected studies using a pre-defined search protocol. The I2 statistics were used to ascertain statistical heterogeneity.

RESULTS

Two hundred and forty citations were identified in our search strategy, of which a total of 34 studies were identified. Twenty-four were excluded from the thirty-four studies. A total of 11 studies met our inclusion criteria shown in the PRISMA. Apart from different z scores reading obtained from various countries and regions, some authors focused on few cardiac parameters while others were exhaustive. The mean z-scores of the cardiac structures from various countries/regions range as follows; The range of Z scores obtained by different studies and regions above are as follows; MV;-1.62-0.7 AV: -1.8 -0.5 TV: -2.71 -0.7; PV ; -1.52- (-0.99) MPA; -1-81 -0.8 LPA;-1.07-0.4; RPA;-0.92- 0.1 IVSD; -0.1.77-1.89 LVPWD; -0.12-1.5 LVPWS; -0.1-0.15 LVPWS; 0.03-0.18 LVIDD; -1.13- (-0.98) LVIDS; -0.84-10.3 respectively. The mean z-score from the pooled studies showed mitral valve diameter as -0.24 ± 0.9 and pulmonary valve annuls as -1.10 ± 0.3. The left ventricular end diastolic diameter is -0.93 ± 0.3 while the left ventricular end systolic diameter is -0.05 ± 0.5. The total pooled sample size of the eleven included studies was 9074 and the mean at 95% interval was 824.9 ± 537.344. The pooled mean is presented under the model of the Mean raw (MRAW) column. The heterogeneity discovered among the selected studies was statistically significant.

CONCLUSION

Due to heterogeneity involved in the reportage of the z-scores of cardiac structures and function, it may be necessary for every region to use their z-scores domiciled in their locale. However, having a pooled mean z-score of cardiac structures and function may be useful in the near future.

Thymus assessments at birth in echocardiography: a preliminary cohort study

BACKGROUND

Echocardiography is a tool used in neonatal period to screen for congenital heart defects and to assess the function of the cardiovascular system. It enables obtaining a three-vessel view (3VV) to show how the superior vena cava, the aorta and the pulmonary trunk relate to each other. A 3VV also provides a view of the thymus gland.

METHODS

It is a preliminary study. Using the thymus measurements obtained in echocardiography of neonates delivered in one healthcare centre, a total of 1,331 thymus records were collected and statistically analysed. The study was conducted on group of 321 preterm neonates and 1,010 full-term neonates. The superior mediastinal view (three-vessel view, 3VV) was chosen for thymus measurements, with the parallel vascular system, including the superior vena cava, the aorta and the pulmonary trunk, with visible branching to the right and left pulmonary artery. Thymus width, depth and thymic 3VV index were measured. Thymic 3VV index (TI 3VV) is defined as a product of multipling the width and the depth of the thymus in three-vessel view projection.

RESULTS

Based on a statistical analysis, a correlation was found of 3VV thymus dimensions and thymic 3VV index with body weight, gestational age and body surface area (BSA). These measurements led to the important finding that the TI 3VV value depends on thymus width and depth, more prominently the latter. The 3VV measurement of thymus depth alone can serve as a screening tool to assess the size of the gland.

CONCLUSIONS

Inclusion of thymic measurements in neonatal echocardiography protocol can be used as a screening tool to assess the size of thymus gland.

Machine Learning-Enabled Fully Automated Assessment of Left Ventricular Volume, Ejection Fraction and Strain: Experience in Pediatric and Young Adult Echocardiography

BACKGROUND

Left ventricular (LV) volumes, ejection fraction (EF), and myocardial strain have been shown to be predictive of clinical and subclinical heart disease. Automation of LV functional assessment overcomes difficult technical challenges and complexities. We sought to assess whether a fully automated assessment of LV function could be reliably used in children and young adults.

METHODS

Fifty normal volunteers (22/28, female/male) were prospectively recruited for research echocardiography. LV volumes, EF, and strain were measured both manually and automatically. An experienced sonographer performed all the manual analysis and recorded the analysis timing. The fully automated analyses were accomplished by 5 groups of observers with different knowledge and medical background. AutoLV and AutoSTRAIN (TomTec) were employed for the fully automated LV analysis. The LV volumes, EF, strain, and analysis time were compared between manual and automated methods, and among the 5 groups of observers.

RESULTS

Software-determined endocardial border detection was achievable in all subjects. The analysis times of the experienced sonographer were significantly shorter for AutoLV and AutoSTRAIN than manual analyses (both p < 0.001). Strong correlations were seen between conventional EF and AutoLV (r = 0.8373), and between conventional three view global longitudinal strain (GLS) and AutoSTRAIN (r = 0.9766). The volumes from AutoLV and three view GLS from AutoSTRAIN had strong correlations among different observers regardless of level of expertise. EF from AutoLV analysis had moderately strong correlations among different observers.

CONCLUSION

Automated pediatric LV analysis is feasible in normal hearts. Machine learning-enabled image analysis saves time and produces results that are comparable to traditional methods.

Precision in Norwood Shunt Sizing: Single Ventricle Reconstruction Trial Public Dataset Analysis

BACKGROUND

Morbidity and mortality after the Norwood procedure remains high. Shunt size selection is not standardized and the impact of shunt size on outcomes is poorly understood. The Single Ventricle Reconstruction trial randomized infants to modified Blalock-Taussig-Thomas shunt (MBTTS) or right ventricle-to-pulmonary artery shunt at the Norwood procedure. We assessed shunt size distribution and its association with postoperative outcomes.

METHODS

We included 544 patients, excluding 5 with ambiguous shunt crossover data. Normalized shunt diameter 1 and 2 were calculated as shunt diameter divided by patient's weight and body surface area, respectively. The primary outcome was 30-day mortality after Norwood. Secondary outcomes were intensive care and total length of stay, and survival to Glenn procedure. Logistic and ordinal regression models evaluated the association of normalized shunt diameter with outcomes.

RESULTS

Thirty-day mortality after Norwood was 11.4% (n = 62), survival to Glenn procedure was 72.6% (n = 395), median length of stay was 14.0 (interquartile range, 9.0-27.7) days and 24.0 (interquartile range, 16.0-41.0) days in the intensive care and total, respectively. Normalized shunt diameters exhibited variation in both shunt types but were not associated with 30-day mortality. Right ventricle-to-pulmonary artery shunt size was not associated with secondary outcomes. However, a MBTTS diameter ≥1.5 mm/kg predicted longer Norwood (odds ratio, 4.89; 95% CI, 1.41-16.90) and intensive care (odds ratio, 4.11; 95% CI, 1.25-13.49]) duration.

CONCLUSIONS

Shunt size selection was variable. Right ventricle-to-pulmonary artery shunt had a wider size range seen with favorable outcomes compared with MBTTS. A MBTTS either too large or too small is associated with worse postoperative outcomes. Refining shunt sizing practices can improve surgical outcomes after the Norwood procedure.

Patterns of Left Ventricular Remodelling in Children and Young Patients with Hypertrophic Cardiomyopathy

Introduction: The aim of this study was to evaluate the age at onset, clinical course, and patterns of left ventricular (LV) remodelling during follow-up in children and young patients with hypertrophic cardiomyopathy (HCM). Methods: We included consecutive patients with sarcomeric or non-syndromic HCM below 18 years old. Three pre-specified patterns of LV remodelling were assessed: maximal LV wall thickness (MLVWT) thickening; MLVWT thinning with preserved LV ejection fraction; and MLVWT thinning with progressive reduction in LV ejection fraction (hypokinetic end-stage evolution). Results: Fifty-three patients with sarcomeric/non-syndromic HCM (mean age 9.4 ± 5.5 years, 68% male) fulfilled the inclusion criteria. In total, 32 patients (60%) showed LV remodelling: 3 patients (6%) exhibited MLVWT thinning; 16 patients (30%) showed MLVWT thickening; and 13 patients (24%) progressed to hypokinetic end-stage HCM. Twenty-one patients (40%) had no LV remodelling during follow-up. In multivariate analysis, MLVWT was a predictor of the hypokinetic end-stage remodelling pattern during follow-up (OR 1.17 [95%CI 1.01-1.36] per 1 mm increase, p-value 0.043), regardless of sarcomeric variants and New York Heart Association class. Two patients with sarcomeric HCM, showing a pattern of MLVWT regression during childhood, experienced progression during adolescence. Conclusions: Different patterns of LV remodelling were observed in a cohort of children with sarcomeric/non-syndromic HCM. Interestingly, a pattern of progressive MLVWT thinning during childhood, with new progression of MLVWT during adolescence, was noted. A better understanding of the remodelling mechanisms in children with sarcomeric HCM may be relevant to defining the timing and possible efficacy of new targeted therapies in the preclinical stage of the disease.

Kidney volume normative values in Central European children aged 0-19 years: a multicenter study

BACKGROUND AND OBJECITVES

The currently available kidney volume normative values in children are restricted to small populations from single-centre studies not assessing kidney function and including none or only a small number of adolescents. This study aimed to obtain ultrasound-based kidney volume normative values derived from a large European White/Caucasian paediatric population with normal kidney function.

METHODS

After recruitment of 1427 children aged 0-19 years, 1396 individuals with no history of kidney disease and normal estimated glomerular filtration rate were selected for the sonographic evaluation of kidney volume. Kidney volume was correlated with age, height, weight, body surface area and body mass index. Kidney volume curves and tables related to anthropometric parameters were generated using the LMS method. Kidney volume predictors were evaluated using multivariate regression analysis with collinearity checks.

RESULTS

No clinically significant differences in kidney volume in relation to height were found between males and females, between supine and prone position and between left and right kidneys. Males had, however, larger age-related kidney volumes than females in most age categories. For the prediction of kidney volume, the highest coefficient correlation was observed for body surface area (r = 0.94), followed by weight (r = 0.92), height (r = 0.91), age (r = 0.91), and body mass index (r = 0.67; p < 0.001 for all).

CONCLUSIONS

This study presents LMS-percentile curves and tables for kidney volume which can be used as reference values for children aged 0-19 years.

Accuracy of glomerular filtration rate estimation using creatinine and cystatin C for identifying and monitoring moderate chronic kidney disease: the eGFR-C study

Background

Estimation of glomerular filtration rate using equations based on creatinine is widely used to manage chronic kidney disease. In the UK, the Chronic Kidney Disease Epidemiology Collaboration creatinine equation is recommended. Other published equations using cystatin C, an alternative marker of kidney function, have not gained widespread clinical acceptance. Given higher cost of cystatin C, its clinical utility should be validated before widespread introduction into the NHS.

Objectives

Primary objectives were to: (1) compare accuracy of glomerular filtration rate equations at baseline and longitudinally in people with stage 3 chronic kidney disease, and test whether accuracy is affected by ethnicity, diabetes, albuminuria and other characteristics; (2) establish the reference change value for significant glomerular filtration rate changes; (3) model disease progression; and (4) explore comparative cost-effectiveness of kidney disease monitoring strategies.

Design

A longitudinal, prospective study was designed to: (1) assess accuracy of glomerular filtration rate equations at baseline (n = 1167) and their ability to detect change over 3 years (n = 875); (2) model disease progression predictors in 278 individuals who received additional measurements; (3) quantify glomerular filtration rate variability components (n = 20); and (4) develop a measurement model analysis to compare different monitoring strategy costs (n = 875).

Setting

Primary, secondary and tertiary care.

Participants

Adults (≥ 18 years) with stage 3 chronic kidney disease.

Interventions

Estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease equations.

Main outcome measures

Measured glomerular filtration rate was the reference against which estimating equations were compared with accuracy being expressed as P30 (percentage of values within 30% of reference) and progression (variously defined) studied as sensitivity/specificity. A regression model of disease progression was developed and differences for risk factors estimated. Biological variation components were measured and the reference change value calculated. Comparative costs of monitoring with different estimating equations modelled over 10 years were calculated.

Results

Accuracy (P30) of all equations was ≥ 89.5%: the combined creatinine-cystatin equation (94.9%) was superior (p < 0.001) to other equations. Within each equation, no differences in P30 were seen across categories of age, gender, diabetes, albuminuria, body mass index, kidney function level and ethnicity. All equations showed poor (< 63%) sensitivity for detecting patients showing kidney function decline crossing clinically significant thresholds (e.g. a 25% decline in function). Consequently, the additional cost of monitoring kidney function annually using a cystatin C-based equation could not be justified (incremental cost per patient over 10 years = £43.32). Modelling data showed association between higher albuminuria and faster decline in measured and creatinine-estimated glomerular filtration rate. Reference change values for measured glomerular filtration rate (%, positive/negative) were 21.5/-17.7, with lower reference change values for estimated glomerular filtration rate.

Limitations

Recruitment of people from South Asian and African-Caribbean backgrounds was below the study target.

Future work

Prospective studies of the value of cystatin C as a risk marker in chronic kidney disease should be undertaken.

Conclusions

Inclusion of cystatin C in glomerular filtration rate-estimating equations marginally improved accuracy but not detection of disease progression. Our data do not support cystatin C use for monitoring of glomerular filtration rate in stage 3 chronic kidney disease.

Trial registration

This trial is registered as ISRCTN42955626.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 11/103/01) and is published in full in Health Technology Assessment; Vol. 28, No. 35. See the NIHR Funding and Awards website for further award information.

Hybrid palliation to promote growth of left ventricle and left ventricular outflow tract

OBJECTIVES

In patients with borderline left hearts or a severe left ventricular outflow tract obstruction, hybrid palliation can be used to stabilize the patient and postpone biventricular repair (BVR). In this study, we analysed growth of left-sided structures and outcomes of these patients.

METHODS

We conducted a retrospective cohort study including patients who received hybrid palliation between January 2010 and September 2023. Echo measurements were collected at hybrid palliation, BVR and last follow-up. Growth of left ventricular structures were analysed.

RESULTS

In 38 patients, hybrid palliation was used to promote growth of left ventricular structures. In total, 15 patients received a Ross-Konno/Yasui procedure, while 23 patients received conventional BVR. In patients with a conventional BVR, a significant increase was found in left ventricular volume indexed by body surface area, Z-score of aortic valve and left ventricular outflow tract between hybrid palliation and BVR. Mitral valve Z-score did not increase significantly. After BVR until follow-up, only increase of the aortic valve Z-scores and left ventricular volume indexed by body surface area was found significant. Of all included patients (n = 38), additional surgical procedures were necessary in 8 patients during the interstage period and 15 patients after BVR. Additional catheter interventions were needed in 14 patients in the interstage period and 15 after BVR. Six patients died, with no mortality in the conventional BVR group.

CONCLUSIONS

Hybrid palliation as part of a staged BVR is a safe and effective initial step and promotes the growth of left ventricular structures in patients with small left-sided heart structures. Close follow-up is mandatory because extra catheter or surgical interventions are frequently needed.

Oxygen uptake efficiency slope in 8- to 12-year-old boys and girls

BACKGROUND

Oxygen uptake efficiency slope (OUES) is an objective physiological measure that can be obtained from a standard graded exercise test. However, there is conflicting evidence regarding sex differences in OUES values in children. Therefore, this study investigated potential sex differences in absolute, ratio-scaled, and allometrically scaled OUES in 8.0- to 12.0-year-old children.

METHODS

Retrospective and prospective data of 18 boys and 22 girls were utilized. All participants had undergone familiarization before performing a maximal cycle ergometer test to determine OUES. These values were also ratio-scaled and allometrically scaled to mass and body surface area (BSA). Group differences were tested via independent sample t-tests (or Mann-Whitney U if not normally distributed).

RESULTS

Absolute OUES values (VO2 mL∙min-1/log10VE L∙min-1) were significantly higher in boys compared to girls (1860.8±359.3 vs. 1514.3±212.6). When scaled to mass (VO2 mL∙kg-1∙min-1/log10VE L∙kg-1∙min-1), OUES was no longer significantly different between groups, but when scaled to BSA (VO2 mL∙m-2∙min-1/log10VE L∙m-2∙min-1), OUES was significantly higher in the boys than the girls (1414.4±204.2 vs. 1268.9±134.6). When allometry was applied for mass (OUES/mass0.444) boys had significantly higher value than girls (350.8±46.7 vs. 305.0±31.5).

CONCLUSIONS

The present study demonstrated that boys had greater OUES values scaled to BSA and allometrically scaled to body mass. These findings provide further evidence of sex differences with OUES values in preadolescent children and implies the need for sex-specific reference values prior to using OUES for the assessment of cardiorespiratory pathology in children.

Comparison of cystatin C-based estimated glomerular filtration rate with measured glomerular filtration rate in a pediatric cohort of patients with chronic kidney disease

BACKGROUND

It is essential to have an accurate assessment of the renal function of patients with chronic kidney disease to monitor, treat, and predict further development of the condition. Measurement of renal function in terms of glomerular filtration rate (GFR) requires either urine or blood sampling, but especially in children, more simple methods of measurement are preferable. The main objective of this study was to examine if the estimated GFR (eGFR) calculated with different cystatin-C-based equations was comparable to the GFR measured by a radiotracer (mGFR) in pediatric patients.

METHODS

In this retrospective study, 28 pediatric patients contributed with 73 pairs of measurements collected within 5 years. Bland-Altman Limits of Agreement were used to evaluate the performance and accuracy of two different cystatin-C-based estimates, the CKiDCrea-CysC and the CKiDU25 respectively, compared to an mGFR based on plasma clearance of technetium-99m-diethylenetriaminepentaacetic acid or chromium-51-ethylenediaminetetraacetic acid.

RESULTS

Using the CKiDCrea-CysC equation, 58.9% of the datasets were within P10 and 87.7% were within P30. The mean difference was 4.8 mL/min/1.73m2 (standard deviation: 8.5 mL/min/1.73m2) and tended to overestimate GFR and thereby overrate the kidney function within the entire GFR range. Using the CKiDU25 equation, 53.4% were within P10 and 93.2% within P30. The mean difference was -2.9 mL/min/1.73m2 (standard deviation: 8.4 mL/min/1.73m2), but the difference varied with the GFR value.

CONCLUSIONS

A cystatin-C-based eGFR provides a viable substitute for monitoring renal function in pediatric patients with chronic kidney disease. However, it has a lower accuracy than mGFR and can therefore not replace mGFR in clinical use.

Unveiling Cardiac Involvement in Juvenile Dermatomyositis Through Speckle-Tracking Echocardiography

Early detection of cardiac involvement in Juvenile Dermatomyositis (JDM) is difficult due to the absence of clinical signs and symptoms, with systolic dysfunction often emerging in late stages and associated with a poor prognosis. This study aimed to employ two-dimensional speckle-tracking echocardiography (STE) for subclinical assessment of left ventricular (LV) systolic failure in JDM and explore potential associations between impaired LV systolic function (LV-GLS) and disease activity. A prospective study enrolled 20 healthy volunteers and 26 JDM patients (< 18 years old) without cardiac symptoms. Clinical data were collected from medical records, and echocardiograms were conducted by a pediatric cardiologist. Our study cohort demonstrated similar age to controls (13.5 ± .6 vs. 13.8 ± 4.7; p = 0.465). Median illness duration at echocardiography was 5 (1.5-17.5) years, and conventional echocardiography indicated normal LV ejection fraction (> 55%) in all participants. However, STE revealed lowered LV GLS in JDM patients (- 22.2 ± 4.1% vs. - 26.5 ± 5.3% p = 0.022). Pulse steroid users displayed lower GLS average values compared to non-users (β = 4.99, 95% CI 1.34-8.64, p = 0.009). Negative correlations existed between LV-GLS and age at diagnosis (r = - 0.499; p = 0.011), diastolic parameters (E/E' ratio) and age at diagnosis (r = - 0.469; p = 0.018), as well as RV global strain and age at diagnosis (r = - 0.443; p = 0.024). Employing STE in JDM patients facilitated the identification of preclinical cardiac dysfunction. Given JDM patients' younger age, early myocardial damage detection through STE may impact treatment decisions and long-term cardiovascular prognosis.

Biological sex does not independently influence core temperature change and sweating of children exercising in uncompensable heat stress

The purpose of this study was to investigate the influence of biological sex, independent of differences in aerobic fitness and body fatness, on the change in gastrointestinal temperature (ΔTgi) and whole body sweat rate (WBSR) of children exercising under uncompensable heat stress. Seventeen boys (means ± SD; 13.7 ± 1.3 yr) and 18 girls (13.7 ± 1.4 yr) walked for 45 min at a fixed rate of metabolic heat production per kg body mass (8 W·kg-1) in 40°C and 30% relative humidity. Sex and peak oxygen consumption (V̇o2peak) were entered into a Bayesian hierarchical general additive model (HGAM) for Tgi. Sex, V̇o2peak, and the evaporative requirement for heat balance (Ereq) were entered into a Bayesian hierarchical linear regression for WBSR. For 26 (12 M and 14 F) of the 35 children with measured body composition, body fat percentage was entered in a separate HGAM and hierarchical linear regression for Tgi and WBSR, respectively. Conditional on sex-specific mean V̇o2peak, ΔTgi was 1.00°C [90% credible intervals (Crl): 0.84, 1.16] for boys and 1.17°C [1.01, 1.33] for girls, with a difference of 0.17°C [-0.39, 0.06]. When sex differences in V̇o2peak were accounted for, the difference in ΔTgi between boys and girls was 0.01°C [-0.25, 0.22]. The difference in WBSR between boys and girls was 0.03 L·h-1 [-0.02, 0.07], when isolated from differences in Ereq. The difference in ΔTgi between boys and girls was -0.10°C [-0.38, 0.17] when sex differences in body fat (%) were accounted for. Biological sex did not independently influence the ΔTgi and WBSR of children exercising under uncompensable heat stress.NEW & NOTEWORTHY Limited studies have investigated the thermoregulatory responses of boys and girls exercising under uncompensable heat stress. Boys and girls often differ in physiological characteristics other than biological sex, such as aerobic fitness and body fat percentage, which may confound interpretations. We investigated the influence of biological sex on exercise thermoregulation in children, independent of differences in aerobic fitness and body fatness.

Truncus arteriosus from prenatal diagnosis to clinical outcome: a single-centre experience

BACKGROUND

The aim of this study was to review our institution's experience with truncus arteriosus from prenatal diagnosis to clinical outcome.

METHODS

and results: We conducted a single-centre retrospective cohort study for the years 2005-2020. Truncus arteriosus antenatal echocardiographic diagnostic accuracy within our institution was 92.3%. After antenatal diagnosis, five parents (31%) decided to terminate the pregnancy. After inclusion from referring hospitals, 16 patients were offered surgery and were available for follow-up. Right ventricle-to-pulmonary artery continuity was preferably established without the use of a valve (direct connection), which was possible in 14 patients (88%). There was no early or late mortality. Reinterventions were performed in half of the patients at latest follow-up (median follow-up of 5.4 years). At a median age of 5.5 years, 13 out of 14 patients were still without right ventricle-to-pulmonary artery valve, which was well tolerated without signs of right heart failure. The right ventricle demonstrated preserved systolic function as expressed by tricuspid annular plane systolic excursion z-score (-1.4 ± 1.7) and fractional area change (44 ± 12%). The dimensions and function of the left ventricle were normal at latest follow-up (ejection fraction 64.4 ± 6.2%, fractional shortening 34.3 ± 4.3%).

CONCLUSIONS

This study demonstrates good prenatal diagnostic accuracy of truncus arteriosus. There was no mortality and favourable clinical outcomes at mid-term follow-up, with little interventions on the right ventricle-to-pulmonary artery connection and no right ventricle deterioration. This supports the notion that current perspectives of patients with truncus arteriosus are good, in contrast to the poor historic outcome series. This insight can be used in counselling and surgical decision-making.

Higher dietary acid load is associated with the risk of hyperuricemia

PURPOSE

Dietary acid load plays a key role in regulating serum uric acid levels. We hypothesized that dietary acid load indices would be positively associated with the odds of hyperuricemia. We aimed to test this hypothesis in a representative sample of Iranian adult population.

METHODS

In this cross-sectional study, a total of 6145 participants aged 35-65 years were recruited from MASHAD cohort study. Dietary intakes were assessed using a 24-h dietary recall. Diet-based acid load was assessed as the potential renal acid load (PRAL), net endogenous acid production (NEAP), and dietary acid load (DAL). Hyperuricemia was defined as serum uric acid greater than the 75th percentile. Multivariable logistic regression models were applied to determine the association between diet-based acid load scores and hyperuricemia.

RESULTS

The mean age of participants was 48.89 ± 8.09 years. Overall, 25.7% had hyperuricemia. According to the full-adjusted model, there was a significant association between higher tertile of PRAL, and DAL and hyperuricemia (Q3 PRAL; OR (95% CI): 1.23 (1.05-1.43), Q3 DAL; OR (95% CI): 1.22 (1.05-1.42)). Regarding NEAP, there was no significant association with hyperuricemia. We also found that dietary intake of total sugars, fiber, calcium, and magnesium was associated with the odds of hyperuricemia in our population.

CONCLUSION

This study showed a significant positive association between two indicators of dietary acid load (PRAL, and DAL) and odds of hyperuricemia among Iranian adults.

Adaptation of Left Ventricular Twist Mechanics in Exercise-Trained Children Is Only Evident after the Adolescent Growth Spurt

BACKGROUND

The extent of structural cardiac remodeling in response to endurance training is maturity dependent. In adults, this structural adaptation is often associated with the adaptation of left ventricular (LV) twist mechanics. For example, an increase in LV twist often follows an expansion in end-diastolic volume, whereas a reduction in twist may follow a thickening of the LV walls. While structural cardiac remodeling has been shown to be more prominent post-peak height velocity (PHV), it remains to be determined how this maturation-dependent structural remodeling influences LV twist. Therefore, we aimed to (1) compare LV twist mechanics between trained and untrained children pre- and post-PHV and (2) investigate how LV structural variables relate to LV twist mechanics pre- and post-PHV.

METHODS

Left ventricular function and morphology were assessed (echocardiography) in endurance-trained and untrained boys (n = 38 and n = 28, respectively) and girls (n = 39 and n = 34, respectively). Participants were categorized as either pre- or post-PHV using maturity offset to estimate somatic maturation.

RESULTS

Pre-PHV, there were no differences in LV twist or torsion between trained and untrained boys (twist: P = .630; torsion: P = .382) or girls (twist: P = .502; torsion: P = .316), and LV twist mechanics were not related with any LV structural variables (P > .05). Post-PHV, LV twist was lower in trained versus untrained boys (P = .004), with torsion lower in trained groups, irrespective of sex (boys: P < .001; girls: P = .017). Moreover, LV torsion was inversely related to LV mass (boys: r = -0.55, P = .001; girls: r = -0.46, P = .003) and end-diastolic volume (boys: r = -0.64, P < .001; girls: r = -0.36, P = .025) in both sexes.

CONCLUSIONS

A difference in LV twist mechanics between endurance-trained and untrained cohorts is only apparent post-PHV, where structural and functional remodeling were related.

Newly Developed Sex-Specific Z Score Model for Coronary Artery Diameter in a Pediatric Population

BACKGROUND

This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice.

METHODS

This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit.

RESULTS

Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula.

CONCLUSION

A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

Speckle-Tracking: Incremental Role in Diastolic Assessment of Pediatric Patients with Chronic Kidney Disease

BACKGROUND

Cardiovascular complications are the leading cause of mortality in pediatric patients with chronic kidney disease (CKD). Echocardiographic assessment of diastolic function in CKD has been limited to spectral and tissue Doppler imaging, known to be less reliable techniques in pediatrics. Two-dimensional Speckle tracking echocardiography (2DST) derived left atrial (LA) strain has recently been confirmed as a robust measure of diastolic function.

OBJECTIVES

To investigate LA strain role in diastolic assessment of children at different stages of CKD.

METHODS

From February 2019 to July 2022, 55 CKD patients without cardiovascular symptoms and 55 controls were evaluated by standard and 2DST echocardiograms. The level of significance was set at 5% (p<0.05).

RESULTS

Patients and controls had similar age [9.78 (0.89 - 17.54) vs. 10.72 (1.03 -18,44) years; p = 0.41] and gender (36M:19F vs. 34M:21F; p=0.84). There were 25 non-dialysis patients and 30 dialysis patients. Left ventricular ejection fraction was ≥ 55% in all of them. Comparing CKD and controls, LA reservoir strain was lower (48.22±10.62% vs. 58.52±10.70%) and LA stiffness index was higher [0.14 (0.08-0.48)%-1 vs. 0.11 (0.06-0.23) %-1]; p<0.0001. LV hypertrophy was associated with lower LA reservoir strain (42.05±8.74% vs. 52.99±9.52%), higher LA stiffness [0.23(0.11 - 0.48)%-1 vs. 0.13 (0.08-0.23) %-1 and filling indexes (2.39±0.63 cm/s x %-1 vs. 1.74±0.47 cm/s x %-1; p<0.0001. Uncontrolled hypertension was associated with lower LA reservoir strain (41.9±10.6% vs. 50.6±9.7; p=0.005).

CONCLUSIONS

LA strain proved to be a feasible tool in the assessment of pediatric CKD patients and was associated with known cardiovascular risk factors.

Predischarge oxygen uptake efficiency slope has short and long-term value in the prognosis of patients after acute myocardial infarction

BACKGROUND

Patients who survive an acute myocardial infarction (AMI) have a higher risk of having a major cardiovascular event (MACE). Cardiopulmonary exercise testing (CPET) could develop prognostic stratification and prescribing exercise prescription. Patients after AMI frequently terminate CPET early with submaximal testing results. We aimed to look at the characteristics of patients' predischarge CPET variables after AMI intervention and find potential CPET variables with prognostic value.

METHODS

Between July 2012 and August 2017, we recruited patients who survived first AMI after primary percutaneous coronary intervention and received predischarge CPET retrospectively in a tertiary medical center of Taiwan. Patients were followed-up on a MACE or administrative censoring occurred (up to 5 years). To identify significant predictors of a MACE, a Cox regression model was used.

RESULTS

One hundred thirteen patients (103 men and 10 women) were studied, with an average age of 58.32 ± 12.49. MACE over 3 months, 2-years, and 5-years was 17.70%, 53.10%, and 62.83%, respectively. The oxygen uptake efficiency slope during the whole during of CPET (OUES 100) divided by body surface area (OUES 100/BSA) was found to be a significant event predictor for MACE at 3-month, 2- and 5-years. Cox regression analysis revealed that those with OUES 100/BSA <0.722 ( p = 0.004), OUES 100/BSA <0.859 ( p = 0.002), and OUES 100/BSA <0.829 ( p = 0.002) had a 7.14-fold, 3.47-fold, and 2.72-fold increased risk of 3-month, 2-year, and 5-year MACE, respectively.

CONCLUSION

It is critical to identify a submaximal predictor during CPET for patients who survive AMI. Our findings suggested that OUES could be a significant prognostic indicator in patients after first AMI in both the short and long term.

Influence of Biological Sex and Fitness on Core Temperature Change and Sweating in Children Exercising in Warm Conditions

PURPOSE

This study aimed to investigate the associations of biological sex and aerobic fitness (i.e., V̇O 2peak ) on the change in gastrointestinal temperature (∆ Tgi ) and whole-body sweat rate (WBSR) of children exercising in warm conditions.

METHODS

Thirty-eight children (17 boys, mean ± SD = 13.7 ± 1.2 yr; 21 girls, 13.6 ± 1.8 yr) walked for 45 min at a fixed rate of metabolic heat production (8 W·kg -1 ) in 30°C and 40% relative humidity. Biological sex and relative V̇O 2peak were entered as predictors into a Bayesian hierarchical generalized additive model for Tgi . For a subsample of 13 girls with measured body composition, body fat percent was entered into a separate hierarchical generalized additive model for Tgi . Sex, V̇O 2peak , and the evaporative requirement for heat balance ( Ereq ) were entered into a Bayesian hierarchical linear regression for WBSR.

RESULTS

The mean ∆ Tgi for boys was 0.71°C (90% credible interval = 0.60-0.82) and for girls 0.78°C (0.68-0.88). A predicted 20 mL·kg -1 ·min -1 higher V̇O 2peak resulted in a 0.19°C (-0.03 to 0.43) and 0.24°C (0.07-0.40) lower ∆ Tgi in boys and girls, respectively. A predicted ~13% lower body fat in the subsample of girls resulted in a 0.15°C (-0.12 to 0.45) lower ∆ Tgi . When Ereq was standardized to the grand mean, the difference in WBSR between boys and girls was -0.00 L·h -1 (-0.06 to 0.06), and a 20-mL·kg -1 ·min -1 higher predicted V̇O 2peak resulted in a mean difference in WBSR of -0.07 L·h -1 (-0.15 to 0.00).

CONCLUSIONS

Biological sex did not independently influence ∆ Tgi and WBSR in children. However, a higher predicted V̇O 2peak resulted in a lower ∆ Tgi of children, which was not associated with a greater WBSR, but may be related to differences in body fat percent between high and low fitness individuals.

When will the Glomerular Filtration Rate in Former Preterm Neonates Catch up with Their Term Peers?

AIMS

Whether and when glomerular filtration rate (GFR) in preterms catches up with term peers is unknown. This study aims to develop a GFR maturation model for (pre)term-born individuals from birth to 18 years of age. Secondarily, the function is applied to data of different renally excreted drugs.

METHODS

We combined published inulin clearance values and serum creatinine (Scr) concentrations in (pre)term born individuals throughout childhood. Inulin clearance was assumed to be equal to GFR, and Scr to reflect creatinine synthesis rate/GFR. We developed a GFR function consisting of GFRbirth (GFR at birth), and an Emax model dependent on PNA (with GFRmax, PNA50 (PNA at which half ofGFR max is reached) and Hill coefficient). The final GFR model was applied to predict gentamicin, tobramycin and vancomycin concentrations.

RESULT

In the GFR model, GFRbirth varied with birthweight linearly while in the PNA-based Emax equation, GA was the best covariate for PNA50, and current weight for GFRmax. The final model showed that for a child born at 26 weeks GA, absolute GFR is 18%, 63%, 80%, 92% and 96% of the GFR of a child born at 40 weeks GA at 1 month, 6 months, 1 year, 3 years and 12 years, respectively. PopPK models with the GFR maturation equations predicted concentrations of renally cleared antibiotics across (pre)term-born neonates until 18 years well.

CONCLUSIONS

GFR of preterm individuals catches up with term peers at around three years of age, implying reduced dosages of renally cleared drugs should be considered below this age.

Relationship of Left Ventricular Mass to Lean Body Mass in the Obese Pediatric Population

Our primary aim was to investigate the relationship between LVM and anthropometric measures including lean body mass (LBM) in obese pediatric subjects compared to normal weight controls. A retrospective chart review identified subjects 2-18 years old who were normotensive and had normal echocardiograms between 1995 and 2020 at Boston Children's Hospital. LVM was calculated with the 5/6 area length rule from 2D echocardiograms. LBM was calculated with equations derived from dual-energy X-ray absorptiometry. Of the 2217 subjects who met inclusion criteria, 203 were obese and 2014 had normal weight. The median age was 11.9 (2.0-18.9); 46% were female. The median LVM was 94.5 g (59.3-134.3) in obese subjects vs. 78.0 g (51.5-107.7) in controls. The median LBM was 37.2 kg (18.9-50.6) in obese subjects vs. 30.5 kg (17.6-40.8) in controls. In control and obese subjects, LBM had the strongest correlation to LVM (R2 0.86, P < 0.001) and (R2 0.87, P < 0.001), respectively. There was at most a modest correlation between tissue Doppler velocity z-scores and LV mass, and the largest was Septal E' z-score in obese subjects (r = - 0.31, P = 0.006). In this cohort, LBM was found to have the strongest relationship to LVM in obese subjects. The largest correlation between tissue Doppler velocity z-scores and LV mass was Septal E' z-score. Future studies will evaluate which measurements are more closely aligned with clinical outcomes in obese children.