Table 4– Respiratory variables, oxidative stress markers and ischaemic reactive hyperaemia (IRH) in 25 patients with severe obstructive sleep apnoea treated with continuous positive airway pressure (CPAP) for 3 months.

Variable	Before CPAP	After CPAP	p-value
BMI kg·m⁻²	33 (30–36)	32 (30–35)	0.091
AHI events·h⁻¹	71 (52–85)	2 (1–3)	0.001
ODI events·h⁻¹	68 (54–83)	5 (2–9)	0.001
SapO₂ minimum, %	72 (62–82)	91 (86–92)	0.001
SapO₂ mean,%	92 (87–93)	95 (93–96)	0.035
T90 %	22 (5–40)	0.4 (0–1.4)	0.001
Malondialdehyde μM	3.2 (2.5–4.2)	1.9 (1.6–2.2)	0.001
8-hydroxydeoxyguanosine ng·mL⁻¹	107 (105–114)	102 (101–106)	0.001
Protein carbonyls nmol·mg protein⁻¹	0.10 (0.05–0.14)	0.10 (0.04–0.12)	0.021
SBP mmHg	140 (120–142)	120 (118–130	0.001
DBP mmHg	80 (77–90)	70 (68–80)	0.001
Morning IRH % baseline	47 (33–74)	127 (89–148)	0.001

Data are presented as median (interquartile range), unless otherwise stated. BMI: body mass index; AHI: apnoea–hypopnoea index; ODI: oxygen desaturation index; S_p,O₂: arterial oxygen saturation measured by pulse oximetry; T90: sleep time spent with S_p,O₂ <90%; SBP: systolic blood pressure; DBP: diastolic blood pressure.