CD4 counts were related to FEV1 (r = 0.349, p < 0.001), FEV1% (r = 0.361, p < 0.001), FVC (r = 0.288, p = 0.002), FVC% (r = 0.323, p < 0.001), FEV1/FVC (r = 0.287, p = 0.002), and HCO3 (r = −0.189, p = 0.044) in OSA (Table 3).These results suggest that a decline in total lymphocyte and CD4 counts may be associated with poor alveolar hypoventilation. This evidence concerns the gene CD4 and obstructive sleep apnea syndrome.