Myokine Levels in Relations with Bone Markers and Adipokines in Children with Prader–Willi Syndrome during Growth Hormone Therapy and Dietary Intervention

Background: Data on the interplay between muscle, bone, and adipose tissue metabolism in normal-weight children with Prader–Willi syndrome (PWS) undergoing growth hormone (GH) therapy and dietary interventions are limited. This study aimed to assess the myokine profile and explore the associations between myokines, bone markers, adipokines, and body composition in these patients. Methods: The study included 26 children with PWS and 26 age-matched healthy controls. Serum levels of irisin, myostatin (MSTN), fibroblast growth factor-2, insulin-like growth factor-I (IGF-I), IGF-binding protein-2, bone alkaline phosphatase (BALP), osteocalcin (OC), carboxylated OC (Gla-OC), periostin, soluble receptor activator of nuclear factor kappa-B ligand, tartrate-resistant acid phosphatase 5b, leptin/soluble leptin receptor, adiponectin, and proinsulin were measured using immunoenzymatic assays. Results: Children with PWS had significantly lower lean mass (p = 0.047) and a higher fat mass/lean mass ratio (p < 0.001) than controls. Irisin levels were lower in the PWS group (p = 0.031), while MSTN levels were similar between the groups. In patients, irisin positively correlated with BALP (p = 0.025) and negatively correlated with Gla-OC (p = 0.041) and periostin (p = 0.005). MSTN was positively associated with proinsulin (p = 0.001) and negatively associated with lean mass (p = 0.015). OC concentration was lower in the PWS group and correlated positively with lean mass (p = 0.052). Conclusions: Children with PWS exhibit altered myokine, osteokine, and adipokine profiles, as well as differences in body composition. Reduced irisin and osteocalcin levels, along with the negative association between MSTN and lean mass, may impair muscle development and bone metabolism. These imbalances could also contribute to future metabolic disorders in patients with PWS.