MPO and obstructive sleep apnea syndrome: The median value of circulating MPO was 115.9 (69.4–183.5) ng/mL, and MMP-9 was 269.2 (196.4–364.1) ng/mL with no significant difference between CAD patients with OSA versus without OSA (for MPO 116.2 (70.3–188.2) vs. 113.2 (66.1–178.9) ng/mL, and for MMP-9 261.7 (188.9–366.3) vs. 290.3 (207.5–356.6) ng/mL, respectively).