Risk factors for pulmonary function alterations in children with metabolic dysfunction-associated fatty liver disease

Children with metabolic dysfunction-associated fatty liver disease (MAFLD) may exhibit abnormal lung function. However, it is unclear whether these abnormalities are independent of BMI. Moreover, the specific patterns of abnormal pulmonary function parameters have not been fully characterized, and the risk factors associated with impaired pulmonary function remain insufficiently understood. This study included 40 overweight or obese children with MAFLD and 30 overweight or obese control subjects without MAFLD. Pulmonary function parameters and anthropometric parameters were compared between children with MAFLD and the control group. Additionally, liver function, lipid and glucose metabolism, and cytokine levels were assessed. Multivariable regression analysis was used to identify risk factors for abnormal pulmonary function in children with MAFLD. No significant difference in BMI was observed between the groups (p = 0.075). Pulmonary function tests showed that FVC was significantly higher in children with MAFLD compared to controls (p < 0.001). In contrast, PEF, FEV1/FVC, FEF50, FEF75, and MMEF were lower in the MAFLD group (p < 0.05). Multivariable regression analysis demonstrated that HOMA-IR was significantly and inversely associated with FEF25 (b = -1.51, 95% CI: -2.33 to -0.69, p = 0.001), FEF50 (b = -1.85, 95% CI: -3.01 to -0.70, p = 0.003), and FEF75 (b = -1.44, 95% CI: -2.53 to -0.35, p = 0.01) among children with MAFLD. Furthermore, IL-1β levels were negatively correlated with MMEF (b = -1.16, 95% CI: -2.17 to -0.149, p = 0.03) and FEF50 (b = -0.63, 95% CI: -1.16 to -0.09, p = 0.02). These findings indicate that children aged 8 to 14 years with MAFLD exhibit higher FVC, along with a lower FEV1/FVC ratio and impaired small airway function compared to controls. This impairment in lung function is independent of BMI. Furthermore, HOMA-IR values and elevated IL-1β levels are key risk factors linked to abnormal small airway function.