Table 5.

Effect of CPAP on Vascular Function

	Intention-to-Treat Group				Per-Protocol Group
	CPAP	Sham CPAP	Difference (CPAP − Sham CPAP) Mean (95% CI)	P Value	CPAP	Sham CPAP	Difference (CPAP − Sham CPAP) Mean (95% CI)	P Value
Endothelial function
Peripheral arterial tonometry	n = 24	n = 21
Reactive hyperemia index					n = 12	n = 4
Baseline	2.0 ± 0.6	2.0 ± 0.6			2.0 ± 0.8	2.0 ± 0.8
Week 12	1.9 ± 0.5	2.1 ± 0.7	−0.2 (−0.5 to 0.2)	0.36	2.2 ± 0.6	2.1 ± 0.6	0.0 (−0.2 to 0.1)	0.54
Flow-mediated dilatation	n = 11	n = 14
Brachial diameter, mm						a
Baseline	4.7 ± 0.5	4.1 ± 0.9
Week 12	4.7 ± 0.6	4.3 ± 0.8	−0.1 (−0.5 to 0.3)	0.46
Dilatation, %						a
Baseline	6.5 ± 3.5	7.0 ± 3.3
Week 12	5.6 ± 2.6	7.3 ± 2.1	−1.4 (−3.4 to 0.6)	0.15
Arterial stiffness
Peripheral arterial tonometry	n = 27	n = 21			n = 12	n = 4
Augmentation index, at 75 bpm
Baseline	13.7 ± 14.7	12.0 ± 14.5			15.9 ± 16.4	6.9 ± 24.0
Week 12	7.3 ± 12.6	11.3 ± 15.1	−6.0 (−10.6 to −1.4)	0.01	5.8 ± 15.3	10.0 ± 30.9	−14.9 (−26.8 to −2.9)	0.02
Pulse wave analysis	n = 23	n = 17
Augmentation index, at 75 bpm
Baseline	23.1 ± 7.1	21.6 ± 7.8				a
Week 12	18.7 ± 7.3	24.1 ± 8.6	−6.4 (−9.3 to −3.6)	<0.0001
Time to reflection, ms						a
Baseline	145.6 ± 10.5	148.3 ± 12.8
Week 12	149.7 ± 13.0	148.2 ± 18.0	6.1 (0.3–12.0)	0.04

± values are raw means ± SD. Baseline values include all participants. The between-group differences are the mean differences at 12 weeks, adjusted for baseline values calculated using general linear models. Per-protocol group included participants who met prespecified adherence criteria of ≥4 h use per night.

Abbreviation: bpm, beats per minute.

^aEffects on flow-mediated dilatation and pulse wave analysis were not reported in per-protocol group because of insufficient numbers.