TNF blockade contributes to restore lipid oxidation during exercise in children with juvenile idiopathic arthritis

Area of Science:

• Pediatric Rheumatology
• Exercise Physiology
• Metabolic Research

Background:

• Juvenile idiopathic arthritis (JIA) is associated with impaired physical function.
• Tumor necrosis factor-alpha (TNF-α) is implicated in JIA pathogenesis and influences lipid and muscle metabolism.
• Understanding energy metabolism in JIA is crucial for managing physical function.

Purpose of the Study:

• To investigate substrate oxidation rates during exercise in children with JIA compared to healthy controls.
• To evaluate the impact of TNF blockade therapy on energy metabolism in children with JIA.

Main Methods:

• A comparative study involving three groups: JIA children without TNF blockade, JIA children with TNF blockade, and healthy controls.
• Participants (n=45) were matched for sex, age, and Tanner stage.
• Submaximal incremental exercise testing on an ergocycle with indirect calorimetry to assess fat and carbohydrate oxidation rates.

Main Results:

• Children with JIA not receiving TNF blockade exhibited significantly lower maximal fat oxidation rates during exercise compared to healthy controls (p=0.007).
• JIA children undergoing TNF blockade showed improved maximal fat oxidation rates compared to those untreated (p=0.31).
• No significant differences in carbohydrate oxidation rates were observed between the groups at equivalent exercise intensities.

Conclusions:

• Exercise-induced lipid metabolism is impaired in children with JIA.
• TNF blockade therapy may enhance fat oxidation capacity in children with JIA, potentially improving energy metabolism during physical activity.