BACKGROUND: The aim of this study was to assess insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) concentrations in children with obstructive sleep apnea-hypopnea syndrome (OSAHS) and to compare the results according to disease severity and duration. METHODS: Fifty-one children with OSAHS underwent polysomnography and were classified as having mild, moderate, or severe disease. All children underwent bilateral tonsillectomy/adenoidectomy or adenoidectomy. IGF-1 and IGFBP-3 concentrations were assessed before surgery and 3 and 6 months after surgery. RESULTS: Before surgery, IGF-1 and IGFBP-3 concentrations were significantly higher (P < .05) in the < 5-y group (125.20 ± 42.38 μg/L and 2.00 ± 0.54 mg/L) compared with the ≥ 5-y group (61.92 ± 19.07 μg/L and 1.20 ± 0.37 mg/L). After surgery, concentrations significantly increased (P < .05) in both groups, but remained lower in the ≥ 5-y group. Before surgery, there were no significant differences in IGF-1 (mild: 93.82 ± 37.52 mg/L; moderate: 109.06 ± 58.42 mg/L; severe: 73.88 ± 28.51 mg/L) and IGFBP-3 (mild: 1.76 ± 0.57 mg/L; moderate: 1.67 ± 0.72 mg/L; severe: 1.33 ± 0.45 mg/L) concentrations by severity. After surgery, concentrations significantly increased (P < .05) in both groups, but did not differ by severity. After adjusting for time after surgery, disease duration, apnea-hypopnea index, time spent at SpO2 < 90%, and body mass index Z score, IGF-1 and IGFBP-3 concentrations significantly decreased with every year of age. CONCLUSIONS: These results suggest that disease duration, but not severity, affects the concentrations of 2 important mediators of growth/development (IGF-1 and IGFBP-3) in children with OSAHS before and after surgery. [ABSTRACT FROM AUTHOR]