Body mass index mediates the association between children's dietary inflammatory index and obstructive sleep apnea-hypopnea syndrome in children: a cross-sectional study.

BACKGROUND

The Children's Dietary Inflammatory Index (C-DII) is associated with elevated body mass index (BMI), a major risk factor for pediatric obstructive sleep apnea-hypopnea syndrome (OSAHS). However, the interrelationships between pro-inflammatory diets, BMI, and OSAHS severity in children remain unclear. This study aimed to examine the association between C-DII and OSAHS severity and assess whether BMI statistically explained the association.

METHODS

This cross-sectional study involved 297 children diagnosed with OSAHS. Dietary intake was assessed using a 3-day 24-h dietary recall (including two weekdays and one weekend) to calculate the C-DII scores. All participants underwent polysomnography to determine the obstructive apnea-hypopnea index (OAHI) as an indicator of OSAHS severity. Multiple linear regression analyses evaluated the association between C-DII tertiles (T1 as reference compared to T2 and T3) and OAHI, adjusting for key sociodemographic and clinical covariates. A mediation analysis using the PROCESS macro quantified the proportion of the association statistically attributable to BMI.

RESULTS

After covariate adjustment, the highest C-DII tertile (T3, pro-inflammatory diet) had a significantly higher OAHI vs. the lowest tertile (T1) (β = 2.04, 95% CI: 0.07-4.01, p = 0.042). This difference is equivalent to an increase of approximately two obstructive events per hour. The association attenuated and lost significance after adding BMI to the model (β = 1.58, 95% CI: -0.37-3.54, p = 0.112). BMI remained strongly associated with OAHI (β = 0.53, p = 0.001). Mediation analysis indicated that BMI statistically accounted for 20.18% of the total observed association between C-DII on OAHI.

CONCLUSIONS

A pro-inflammatory diet (higher C-DII score) is associated with more severe pediatric OSAHS. This association was largely statistically explained by BMI. Causality cannot be inferred from this cross-sectional study. These findings support integrating dietary and weight strategies in pediatric OSAHS care. Nonetheless, longitudinal studies are needed to clarify diet-specific effects beyond weight control.