We found a significant and positive correlation between the increase in IGFBP4 at baseline with AHI (r = .575, p < 0.001), AI (r = .703, p < 0.001), HbA1c (r = 0.501, p = 0.003), and WBC (r = 0.380, p = 0.026) and an inverse correlation with O2 saturation (r = −0.423, p = 0.033) and HDL (r = −0.378, p = 0.028) in people with OSA. This evidence concerns the gene IGFBP4 and obstructive sleep apnea syndrome.