CLOCK and obstructive sleep apnea syndrome: Results: In the OSA group, the subjective amplitude (AM score of CQ) positively correlated with all circadian clock genes in the morning (R ≥ 0.230 and p < 0.05 for each one), while the morningness–eveningness (ME score of CQ) was only associated with the evening BMAL1 level (R = 0.192; p = 0.044).