Obesity‑related kidney disease: a review on ultrasound applications

Abstract

Pediatric obesity is a growing global health concern, associated with metabolic, cardiovascular, and kidney complications. Early identification and intervention are crucial to preventing long-term morbidity. This review examines the epidemiology, pathophysiology, and clinical implications of childhood obesity, focusing on its impact on kidney health. We discuss non-invasive diagnostic tools, including kidney ultrasound, and evidence-based management strategies. Obesity in children is linked to hypertension, insulin resistance, and early signs of kidney dysfunction, including increased kidney echogenicity and hyperfiltration. Ultrasound findings may serve as early markers of kidney involvement, potentially guiding risk stratification and intervention. Addressing pediatric obesity requires a multidisciplinary approach, incorporating lifestyle modifications, medical management, and early detection of organ damage. The aim of this narrative review is to summarize the pathophysiology of pediatric obesity-related kidney damage, current evidence on ultrasound-based screening, and possible diagnostic techniques. Further research is needed to validate ultrasound as a routine screening tool for obesity-related kidney disease in children.

Keywords: Doppler; Kidney; Metabolic syndrome; Nephrology; Obesity; Pediatric ultrasound.

Fig. 1

Pathophysiology of obesity-related kidney dysfunction. This figure depicts the critical pathways leading to kidney impairment in obesity, including hemodynamic alterations, metabolic disruptions, and lipid nephrotoxicity. These factors collectively contribute to kidney hyperfiltration and glomerulosclerosis, culminating in chronic kidney disease

Fig. 2

Kidney length. B-mode US images of the right kidney on the longitudinal scan plane, respectively in 2-year-old (a), 8-year-old (b), 11-year-old (c), and 17-year-old (d) patients, allow us to measure the craniocaudal kidney length. The measurement calipers are set (white arrowheads), showing different measures, respectively 6 cm (a) in the toddler, 8 cm in the school-aged children (b,c), and 10 cm (d) in the adolescent patient

Fig. 3

Kidney width and depth. B-mode US image of the kidney on the transversal scan plane (short axis), in a 2-year-old patient, allows us to measure respectively the width (yellow arrow) and depth (blue arrow)

Fig. 4

Kidney cortical thickness. B-mode US image of the right kidney on the longitudinal scan plane (white arrow, long axis), in a 17-year-old patient, allows us to measure respectively the cortical thickness (red arrow), measured perpendicularly from the outer margin of the kidney to the corticomedullary junction, and medullary thickness (blue arrow)

Fig. 5

Kidney arterial RI measurement. (a) A sample volume (black arrowhead) is placed within an arcuate artery of an 11-year-old male patient, under color Doppler guidance, and spectral analysis of vascular signals (b) is obtained. The measurement calipers are set at the PSV (24.0 cm/sec, white arrow) and EDV (10.2 cm/sec, white arrowhead) of a waveform, and the RI is calculated (0.57) according to the formula (PSV-EDV)/PSV. EDV, end-diastolic velocity; RI, resistive index; SV, peak systolic velocity