Reference indices for evaluating kidney dimensions in children using anthropometric measurements

Kidney volume measurement and predictive modeling in children aged 0-18 years using a computer-assisted surgery system

This study aimed to measure the normal renal volume in children and adolescents aged 0-18 years from the eastern coastal region of China using the computer-assisted surgery (CAS) system. Accurate measurement of kidney volume is important as a marker for follow-up in patients with congenital anomalies. We established reference ranges for renal volume based on age, height, and weight, and developed predictive models using commonly available clinical data. A total of 803 children and adolescents participated, with clinical data including age, gender, height, weight, body mass index (BMI) and body surface area (BSA) collected. The Hisense CAS system was employed to perform 3D reconstructions of CT images, allowing precise measurement of left and right kidney volumes. Statistical analysis revealed a significant difference in size between the left and right kidneys (P < 0.01), with the left kidney being larger in 79.08% of cases. Age, height, weight, BMI, and BSA were all significantly correlated with kidney volume, with BSA showing the strongest correlation. We developed predictive formulas based on height and weight with good accuracy (R² = 0.896 for left kidney and R² = 0.891 for right kidney). These findings provide reference values for renal volume and offer useful tools for early detection and monitoring of renal abnormalities in the pediatric population.

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.

Widespread kidney anomalies in children with Down syndrome

BACKGROUND

Rare autopsy studies have described smaller kidneys as well as urinary tract anomalies in Down syndrome. This observation has never been investigated in vivo and little is known about the possible consequences upon kidney function. Here we wish to confirm whether children with Down syndrome have smaller kidneys and to evaluate their kidney function in vivo.

METHODS

This retrospective cohort study enrolled 49 children with Down syndrome, as well as 49 age- and sex-matched controls at the Queen Fabiola Children's University Hospital in Brussels, Belgium. Doppler and kidney ultrasonography, spot urine albumin to creatinine ratio, estimated glomerular filtration rate (eGFR), and anthropometric data were recorded.

RESULTS

Kidney size in children with Down syndrome was smaller than age- and sex-matched controls in terms of length (p < 0.001) and volume (p < 0.001). Kidney function based on eGFR was also decreased in Down syndrome compared to historical normal. Twenty-one of the children with Down syndrome (42%) had eGFR < 90 mL/min/1.73 m², with 5 of these (10%) having an eGFR < 75 mL/min/1.73 m². In addition, 7 of the children with Down syndrome (14%) had anomalies of the kidney and/or urinary tract that had previously been undiagnosed.

CONCLUSIONS

Children with Down syndrome have significantly smaller kidneys than age-matched controls as well as evidence of decreased kidney function. These findings, in addition to well-noted increased kidney and urologic anomalies, highlight the need for universal anatomical and functional assessment of all individuals with Down syndrome. A higher resolution version of the Graphical abstract is available as Supplementary information.

Early childhood height-adjusted total kidney volume as a risk marker of kidney survival in ARPKD

Autosomal recessive polycystic kidney disease (ARPKD) is characterized by bilateral fibrocystic changes resulting in pronounced kidney enlargement. Impairment of kidney function is highly variable and widely available prognostic markers are urgently needed as a base for clinical decision-making and future clinical trials. In this observational study we analyzed the longitudinal development of sonographic kidney measurements in a cohort of 456 ARPKD patients from the international registry study ARegPKD. We furthermore evaluated correlations of sonomorphometric findings and functional kidney disease with the aim to describe the natural disease course and to identify potential prognostic markers. Kidney pole-to-pole (PTP) length and estimated total kidney volume (eTKV) increase with growth throughout childhood and adolescence despite individual variability. Height-adjusted PTP length decreases over time, but such a trend cannot be seen for height-adjusted eTKV (haeTKV) where we even observed a slight mean linear increase of 4.5 ml/m per year during childhood and adolescence for the overall cohort. Patients with two null PKHD1 variants had larger first documented haeTKV values than children with missense variants (median (IQR) haeTKV 793 (450–1098) ml/m in Null/null, 403 (260–538) ml/m in Null/mis, 230 (169–357) ml/m in Mis/mis). In the overall cohort, estimated glomerular filtration rate decreases with increasing haeTKV (median (IQR) haeTKV 210 (150–267) ml/m in CKD stage 1, 472 (266–880) ml/m in stage 5 without kidney replacement therapy). Strikingly, there is a clear correlation between haeTKV in the first eighteen months of life and kidney survival in childhood and adolescence with ten-year kidney survival rates ranging from 20% in patients of the highest to 94% in the lowest quartile. Early childhood haeTKV may become an easily obtainable prognostic marker of kidney disease in ARPKD, e.g. for the identification of patients for clinical studies.