TABLE 1.

Patient characteristics

Characteristic	All patients	Responders#	Non-responders	p-value¶
Subjects	36	9	27
Demographics
Age years	55±2	53±4	55±2	0.7
Male/female	26/10	6/3	20/7	0.7
Race				0.015
Black	9	5	4
White	25	3	22
Asian	0	0	0
Other	1	0	1
Body mass index kg·m−2	31.1±0.7	32.3±1.2	30.6±0.8	0.3
Neck circumference cm	40.6±0.5	40.2±1.0	40.7±0.7	0.7
Systolic blood pressure+ mmHg	136.8±2.4	134.9±3.7	137.5±2.9	0.6
Diastolic blood pressure+ mmHg	80.7±1.9	79.7±3.8	81.1±2.2	0.8
Current use of anti-hypertensive medication n [%]	12 [33]	1 [11]	11 [41]	0.2
Currently treated				0.06
CPAP	12	1	11
Oral appliance therapy	2	0	2
Untreated	22	8	14
Polysomnography§
AHI events·h−1	57.9±22.1	56.6±7.7	58.3±4.3	0.8
Central eventsƒ	4.7±2.0	8.5±5.7	3.4±1.8	0.3
Hypopnoeasƒ	47.3±5.4	61.9±11.3	42.5±6.0	0.12
Arousalsƒ	88.8±4.9	79.1±5.2	92.1±6.2	0.3
Nadir oxygen saturation %	87.1±4.8	89.2±1.5	86.4±0.9	0.13
Stage 1 sleep as % total sleep time	25.9±22.0	22.3±5.1	27.1±4.6	0.6

Data are presented as n or mean±SEM, unless otherwise indicated. CPAP: continuous positive airway pressure; AHI: apnoea–hypopnoea index.

^#: responders are defined by a ≽50% reduction in AHI;

^¶: t-tests were used for continuous variables and Fisher exact tests were used for categorical variables (including black versus not black, treated versus not treated);

⁺: morning, supine, off treatment (sham night);

^§: polysomnography refers to the sham night; respiratory event and oxygenation data reflect supine non-random eye movement sleep;

^ƒ: data presented as % of respiratory events.