Elevated serum aminotransferase levels in children at risk for obstructive sleep apnea

Background: Fatty liver disease (FLD) is a highly prevalent condition in obese (Ob) children, who are at increased risk for obstructive sleep apnea (OSA). However, the contribution of OSA to FLD remains unknown. Design: Prospective study. Setting: Polysomnographic evaluation and assessment of plasma levels of insulin, glucose, and lipids, and liver function tests. Participants: A total of 518 consecutive snoring children 4 to 17 years of age who were being evaluated for habitual snoring and suspected OSA. Results: A total of 376 children had body mass index z score of < 1.20 (non-Ob children), 3 children (<1%) had elevated serum aminotransferase (LFT) levels, and 248 had OSA (65.9%). Among the 142 overweight/Ob children, 46 had elevated LFT levels (32.4%); of these children, 42 had OSA (91.3%). In contrast, OSA was present in only 71.8% of Ob children without elevated LFT level (p < 0.01). Insulin resistance and hyperlipidemia were more likely to occur in children with FLD. Furthermore, FLD was improved after treatment of OSA in 32 of 42 Ob children (p < 0.0001). Conclusion: Increased liver enzyme levels are frequently found in Ob snoring children, particularly among those with OSA and/or metabolic dysfunction. Effective treatment of OSA results in improved liver function test results in the vast majority of these patients.