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

Objectives: In children with snoring, increased production of leukotriene B (LTB) may promote tonsillar hypertrophy and sleep-disordered breathing (SDB) or conversely SDB may enhance LTB synthesis. We explored whether: i) high LTB serum levels predict tonsillar hypertrophy; and ii) SDB severity correlates with LTB serum concentration.

Methods: Normal-weight children with SDB or controls underwent polysomnography and measurement of LTB serum concentration. Tonsillar hypertrophy was the main outcome measure and high LTB 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 level were calculated. The control subgroup and subgroups of subjects with increasing SDB severity were compared regarding LTB concentration by Kruskal-Wallis test. Spearman's correlation co-efficient was applied to assess the association of LTB 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 serum concentration (P = 0.64). High LTB (>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 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 levels, but high LTB concentration predicted tonsillar hypertrophy.