Correlation of salivary resistin levels with obstructive sleep apnea syndrome in pediatric subjects

Background and Objective: Obstructive sleep apnea syndrome (OSAS) is considered to be closely related to systemic inflammation. Resistin levels have been demonstrated to be a measure of systemic inflammation. For children, salivary resistin (SR) sampling is an easy and pain-free method for sample collection and is optimal for multiple sampling. Therefore, we aimed to evaluate correlations among SR levels, objective polysomnography (PSG) parameters, and subjective sleep symptoms. Methods: Fifty-six children who attended our clinic over 1 year were enrolled prospectively; these children underwent clinical evaluation, questionnaire studies, and PSG. SR was measured at 2 points: at night before PSG and in the early morning after PSG. Results: The subjects (n = 56) were divided into the control [n = 23, apnea hypopnea index (AHI) < 1] and OSAS (n = 33, AHI ≥ 1) groups. SR levels after PSG in the OSAS and control groups were similarly higher than that before PSG. There was no significant difference in SR levels between the two groups and among the control and OSAS subgroups. SR levels in the OSAS subgroups were not related to AHI, tonsil size, AN (adenoid-nasopharyngeal) ratio, questionnaire results, lowest oxygen saturation, and oxygen desaturation index (ODI). Conclusions: SR levels had no significant correlation with AHI, scores of the Korean version of modified pediatric Epworth Sleepiness Scale, the lowest oxygen saturation, and ODI; SR levels exhibited diurnal variations regardless of the presence of OSAS. However, there is no consensus regarding the relationship between resistin levels and OSAS. Further studies should be pursued in the future.