Citation: Pappalardo, M.; Gori, L.; Randazzo, E.; Morganti, R.; Scaglione, M.; Valiani, M.; Beni, A.; Di Cicco, M.; Peroni, D.G.; Franzoni, F.; et al. Ultrasound and Clinical Alterations in the Foot of Children with Obesity and Diabetes. Diagnostics 2023, 13, 2781. https://doi.org/10.3390/ diagnostics13172781 Academic Editors: Aristeidis H. Zibis, Dimitri Poddighe and Micol Romano Received: 26 June 2023 Revised: 22 August 2023 Accepted: 25 August 2023 Published: 28 August 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). diagnostics Article Ultrasound and Clinical Alterations in the Foot of Children with Obesity and Diabetes Martina Pappalardo 1,† , Laura Gori 1,† , Emioli Randazzo 1 , Riccardo Morganti 2 , Michelangelo Scaglione 3 , Margherita Valiani 1 , Alessandra Beni 1 , Maria Di Cicco 1,4 , Diego G. Peroni 1,4 , Ferdinando Franzoni 4 and Pasquale Comberiati 1,4, * 1 Azienda Ospedaliero Universitaria Pisana, UO Pediatria Universitaria, 56126 Pisa, Italy 2 Section of Statistics, University Hospital of Pisa, 56126 Pisa, Italy 3 First Orthopedic and Traumatologic Clinic, University of Pisa, 56126 Pisa, Italy 4 Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy * Correspondence: pasquale.comberiati@unipi.it † These authors contributed equally to this work. Abstract: Background. Alterations in plantar soft tissues are often reported in adults with diabetes, whereas data on children are conflicting. Also, the extent of foot damage caused by excess body fat in children has not been fully characterized yet. This study aimed to address the relationship between body mass and structural changes of the foot in children and adolescents with and without diabetes. Methods. In a case-control study, 43 participants (age 13 ± 2.6 years) were recruited, 29 (67%) with type 1 diabetes (T1D) and 14 (33%) controls. Anthropometric parameters [body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR)], foot posture index-6 (FPI-6) for static foot posture, and navicular drop test (NDT) for medial longitudinal arch height (MLA) were measured in all participants. The thickness of the midfoot plantar fascia (MPF) and medial midfoot fat pad (MMFP) were quantified using ultrasound. Results. No differences in clinical and ultrasonographical parameters were observed between the study groups. MMFP thickness was correlated with MPF thickness (p = 0.027). MMFP and MPF thicknesses were positively associated with BMI (p < 0.001 and p = 0.013, respectively), WC (p < 0.001 and p = 0.013), and WHtR (p < 0.001 and p = 0.026). The NDT measured on the right and left foot correlated with WHtR (p = 0.038 and p = 0.009, respectively), but not with WC and BMI. Conclusions. Children with T1D show structural alterations of plantar soft tissues which seem related to body mass increase rather than diabetes pathology. Ultrasound is a valuable tool to assess early structural changes of the foot in young people with an elevated BMI. Keywords: anthropometry; body mass; diabetes; foot; obesity; plantar fascia; posture; ultrasound 1. Introduction Excess body fat mass is associated with musculoskeletal complications and alterations of growth patterns of the limbs and trunk in children [1]. Children with obesity show accelerated skeletal maturation, are taller, and have relatively shorter legs compared to their leaner peers [2,3]. The feet of children who are overweight or obese are characterized by structural lowering of the medial longitudinal arch (MLA), large footprints, an increase in plantar pressure in correspondence of the mid-lateral regions of the midfoot and forefoot, and an increase in the medial midfoot fat pad (MMFP) thickness [1,4–6]. A greater MMFP thickness is hypothesized by some authors to have a protective function for the development of the bone architecture of the MLA [1]. However, Riddiford- Harland et al. [5], did not detect a strong association between midfoot plantar pressures and excess fat padding, thus postulating that the MMFP reflects excess body fat mass rather than having a load adaptation function. Diagnostics 2023, 13, 2781. https://doi.org/10.3390/diagnostics13172781 https://www.mdpi.com/journal/diagnostics