TNF and obstructive sleep apnea syndrome: However, the TNF-α in the pharyngeal lavage (SMD 0.63, 95%CI: 0.28 to 0.98, P = 0.370), saliva (SMD 0.46, 95%CI: − 0.05 to 0.96, P = 0.907), and the peripheral blood mononuclear cells (SMD 1.86, 95%CI: 1.28 to 2.44, P = 0.243) of OSA had no more statistical significance than they did in counterparts of healthy controls (Fig. 5).