Serum leukotriene B4 levels, tonsillar hypertrophy and sleep-disordered breathing in childhood

Abstract Objectives In children with snoring, increased production of leukotriene B 4 (LTB 4 ) may promote tonsillar hypertrophy and sleep-disordered breathing (SDB) or conversely SDB may enhance LTB 4 synthesis. We explored whether: i) high LTB 4 serum levels predict tonsillar hypertrophy; and ii) SDB severity correlates with LTB 4 serum concentration. Methods Normal-weight children with SDB or controls underwent polysomnography and measurement of LTB 4 serum concentration. Tonsillar hypertrophy was the main outcome measure and high LTB 4 serum level (>75 t h percentile value in controls) was the primary explanatory variable. Odds ratio (OR) and the corresponding 95% confidence intervals (CI) for tonsillar hypertrophy in children with versus without high LTB 4 level were calculated. The control subgroup and subgroups of subjects with increasing SDB severity were compared regarding LTB 4 concentration by Kruskal-Wallis test. Spearman's correlation co-efficient was applied to assess the association of LTB 4 concentration with SDB severity. Results A total of 104 children with SDB and mean obstructive apnea-hypopnea index-AHI of 4.8 ± 5.3 episodes/h (primary snoring: n = 19; mild SDB: n = 49; moderate/severe SDB: n = 36) and 13 controls (no snoring; AHI: 0.4 ± 0.2 episodes/h) were recruited. The four study subgroups were similar regarding LTB 4 serum concentration (P = 0.64). High LTB 4 (>170.3 pg/mL) was a significant predictor of tonsillar hypertrophy after adjustment for age and gender (OR 3.0 [1.2–7.2]; P = 0.01). There was no association between AHI or desaturation index and LTB 4 serum concentration (r = −0.08; P = 0.37 and r = −0.1; P = 0.30, respectively). Conclusion No association was identified between SDB severity and LTB 4 levels, but high LTB 4 concentration predicted tonsillar hypertrophy.