Serum Clara cell secretory protein (CC-16) in non-smoking patients with obstructive sleep apnea.

OBJECTIVE: This study aimed to determine the association between the severity of obstructive sleep apnea (OSA) and serum Clara cell protein (CC16) levels in non-smoking patients with OSA. METHODS: This prospective study included non-smoking patients who presented with sleep-related disturbances and underwent polysomnography (PSG). The serum CC16 level was measured and its relationship to PSG parameters was investigated. RESULTS: The study included 128 patients (83 men) with a mean age of 48.4 ± 11.9. OSA was detected in 66 men (70%) and 29 women (30%) (p = 0.051). The severity of OSA was mild in 32 (25%), moderate in 28 (22%), and severe in 35 (27%) of the patients. There was no significant difference in CC16 levels between the OSA group (1746 ± 1006) and the OSA negative group (1721 ± 1201, p = 0.91) levels. There was no significant difference between the CC16 levels of the each four groups. Mean serum CC16 levels were significantly lower in OSA negative men than OSA positive men (777 vs 1462, p = 0.005). No significant difference was observed in CC16 values according to OSA severity in women. CONCLUSION: The serum CC16 level does not differ between non-smoking OSA patients and OSA negative patients.