TNF and obstructive sleep apnea syndrome: Positive correlations between IL-1β and all the periodontal parameters were found only in G2 (P), whereas positive correlations between IL-6, IL -17A, IL-33, TNF-α and periodontal parameters PD and BOP (%) were found in G3 (OSA) and G4 (P-OSA) in GCF and saliva (Table 3).