ESPE Abstracts

Objective: This study aims to assess the potential predictive value of impulse oscillometry (IOS) and hepatic fat content as an alternative diagnostic tools to polysomnography (PSG) for obstructive sleep apnea syndrome (OSAS) in obese children and adolescents.

Method: The study included obese children with a body mass index (BMI) above the 95th percentile. OSAS was assessed via PSG in obese children. Hypopnea was defined as a 30% reduction in nasal airflow and a 3% desaturation/arousal. Pulmonary functions were evaluated using IOS and spirometry with the Jaeger MasterScreen IOS system. Hepatosteatosis was assessed through IDEAL-IQ sequence of liver MRI. Additionally, patients were evaluated by an otorhinolaryngologist for adenoid hypertrophy.

Results: In this study, 63 patients (54% females) were evaluated. OSAS was identified in 33.3% (n = 21) of the patients. The BMI SDS was higher in patients with OSAS (3.29±0.79 vs. 2.78±0.69; P = 0.010). Significant adenoid hypertrophy was observed in 23.8% (n = 15) of the patients. Among these, 66.7% (n = 10) had OSAS compared to 22.9% (n = 11) without adenoid hypertrophy (P = 0.002). The median apnea-hypopnea index in patients with OSAS was 8.3/h (IQR:2.2-15.9), with a median minimum saturation during sleep of 82% (IQR:79%-87%) and a median mean saturation of 94% (IQR:93%-95%). Hepatosteatosis was present in 67.5% (n = 27) of the 40 patients whose liver MRIs were evaluated. Notably, all patients with OSAS exhibited hepatosteatosis (P = 0.004). The median hepatic fat content was significantly higher in patients with OSAS (13.9%, IQR:7.8%-19.8%) compared to those without OSAS (5.8%, IQR:2.8%-8.8%; P <0.001). ROC analysis indicated that a fatty liver ratio above 8% had a sensitivity of 75.0% and a specificity of 71.4% (AUC: 0.857 [95% CI 0.735-0.980], P <0.001) for predicting OSAS. In IOS evaluation, R5Hz and R20Hz values were higher in the OSAS group (R5Hz: 0.77±0.28 kPa/(L/s) vs. 0.57±0.14 kPa/(L/s); P = 0.004 and R20Hz: 0.53±0.13 kPa/(L/s) vs. 0.44±0.09 kPa/(L/s); P = 0.001). ROC analysis showed that an R5Hz value above 0.6 had a sensitivity of 81.0% and a specificity of 69.0% (AUC: 0.755 [95% CI 0.611-0.899], P = 0.001), and an R20Hz value above 0.45 had a sensitivity of 81.0% and a specificity of 59.5% (AUC: 0.732 [95% CI 0.590-0.875], P = 0.004) for predicting OSAS. Spirometric analysis didn't reveal any significant differences between the two groups.

Conclusion: Hepatic fat content measured by IDEAL-IQ sequence of MRI, along with R5 and R20 parameters measured by IOS are predictors of OSAS in obese children and adolescents.