Muscle function and architecture in children with juvenile idiopathic arthritis

Pierre Bourdier (1) , Anthony Birat (1) , Emmanuelle Rochette (2, 3, 4) , Éric Doré (1) , Daniel Courteix (1) , Frédéric Dutheil (5, 6, 7, 8) , Bruno Pereira (9) , Sébastien Ratel (1) , Etienne Merlin (2, 3, 10) , Pascale Duché (1, 4)

1 AME2P - Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques
2 CIC Clermont Ferrand
3 CHU Clermont-Ferrand
4 IAPS - Impact de l'Activité Physique sur la Santé
5 LAPSCO - Laboratoire de Psychologie Sociale et Cognitive
6 Service Santé Travail Environnement [CHU Clermont-Ferrand]
7 WittyFit
8 ACU - Australian Catholic University
9 DRCI - Direction de la recherche clinique et de l’innovation [CHU Clermont-Ferrand]
10 UNH - Unité de Nutrition Humaine

Aim: To assess muscle function and functional abilities in children with juvenile idiopathic arthritis (JIA). Methods: Fourteen children with JIA and 14 healthy controls matched for age and sex were included. Muscle characteristics, both structural (thickness, cross-sectional area (CSA) and fascicle angle) and qualitative (intermuscular adipose tissue : IMAT) were assessed on thigh muscles using ultrasound and peripheral quantitative computed tomography (pQCT). Muscle function and functional abilities were determined from the assessment of maximal voluntary isometric contraction force (MVIC) of the knee extensors and vertical jump performance. Results: No significant difference in MVIC force was observed between both groups. However, squat jump height was significantly reduced in children with JIA (18.3 ± 5.4 vs 24.3 ± 7.9 cm, p<0.05). Furthermore, no difference in structural parameters was observed. Nevertheless, IMAT/CSA (0.22 ± 0.02 vs 0.25 ± 0.03 mm 2 ; p=0.01) was significantly lower in children with JIA compared to healthy peers. Conclusion: Muscle dimensions, architecture and function were comparable between children with JIA and healthy children. Only IMAT area was found to be lower in JIA. These outcomes could be associated with a lower physical activity level in children with JIA compared to healthy children.

Mots clés: Inflammation; Growth; Muscle; IMAT; Paediatrics

Domaines: Physiologie [q-bio.TO]; Pédiatrie; Médecine humaine et pathologie

Pierre Bourdier, Anthony Birat, Emmanuelle Rochette, Éric Doré, Daniel Courteix, et al.. Muscle function and architecture in children with juvenile idiopathic arthritis. Acta Paediatrica, 2021, 110 (1), pp.280-287. ⟨10.1111/apa.15335⟩. ⟨hal-03024973⟩