Table 3.

Baseline (normoxic) values measured prior to graded hypoxia exposure at initial and final visits. Data shown are mean (SD).

	Allopurinol	Losartan	Placebo	P-value*	P-value¶
MSNA (bursts/min)
Initial	26.7 (12.0)	20.6 (9.8)	22.5 (11.1)	0.189
Final	26.4 (11.4)	27.3 (12.4)	21.7 (10.8)	0.267	0.130
MSNA (bursts/100 heart beats)
Initial	39 (17)	30 (14)	33 (18)	0.192
Final	39 (17)	40 (15)	32 (16)	0.184	0.110
Heart rate (beats/min)
Initial	68.8 (9.2)	70.0 (10.1)	72.5 (11.2)	0.390
Final	69.3 (8.8)	70.1 (10.1)	71.8 (11.9)	0.665	0.887
MAP (mmHg)
Initial	94.1(11.1)	94.1(8.3)	97.4(10.4)	0.371
Final	89.5(10.4)	84.0(8.1)	97.5(10.1)	< 0.001x,y,z	< 0.001x,y,z
Systolic pressure (mmHg)
Initial	136.9 (18.3)	136.7 (14.3)	139.7 (16.4)	0.744
Final	129.5 (15.2)	122.0 (14.2)	139.6 (14.1)	< 0.001y,z	< 0.001x,y,z
Diastolic pressure (mmHg)
Initial	72.7(9.1)	72.8(8.1)	75.9(9.3)	0.301
Final	69.5(9.7)	64.7(6.6)	76.6(9.5)	< 0.001x,y,z	0.001x,z
FVC (ml/min/dL/mmHg)
Initial	0.43 (0.20)	0.41 (0.21)	0.49 (0.31)	0.420
Final	0.55 (0.31)	0.42 (0.17)	0.51 (0.29)	0.185	0.522
CVC (velocity-time integral/mmHg)
Initial	0.27 (0.97)	0.32 (0.13)	0.33 (0.11)	0.150
Final	0.31 (0.12)	0.36 (0.14)	0.34 (0.12)	0.479	0.139
VE (liters/min)
Initial	9.3 (2.1)	8.9 (1.7)	9.3 (2.1)	0.692
Final	9.8 (2.6)	8.9 (2.1)	8.8 (1.9)	0.181	0.095
VT (liters)
Initial	0.66 (0.27)	0.64 (0.21)	0.72 (0.23)	0.458
Final	0.69 (0.21)	0.66 (0.22)	0.61 (0.17)	0.434	0.028
fB (breaths/min)
Initial	15.8 (5.0)	15.3 (4.1)	14.5 (4.6)	0.483
Final	16.1 (5.9)	15.0 (4.0)	15.6 (4.3)	0.680	0.420
VT/Ti (l/sec)
Initial	0.38 (0.09)	0.35 (0.06)	0.36 (0.08)	0.443
Final	0.40 (0.11)	0.36 (0.08)	0.34 (0.07)	0.041y	0.090
SaO2 (%)
Initial	95.6 (1.2)	95.5 (0.9)	95.6 (1.0)	0.895
Final	95.7 (1.0)	95.3 (1.1)	95.2 (1.0)	0.120	0.183
PETCO2 (mmHg)
Initial	41.4 (4.0)	41.8 (3.8)	41.6 (3.3)	0.923
Final	41.9 (3.7)	42.3 (3.1)	42.9 (3.6)	0.591	0.503

MSNA, muscle sympathetic nerve activity; MAP, mean arterial pressure; FVC, forearm vascular conductance; CVC, cerebral vascular conductance; V_E, minute ventilation; VT, tidal volume; f_B, breathing frequency; VT/T_i, tidal volume;inspiratory time ratio; SaO₂, arterial oxygen saturation; PETCO₂, end-tidal CO₂ tension

^*P-value for between-group comparison at each time point

^¶P-value for group-by-time interaction, adjusted for average daily CPAP use (min)

Pairwise comparisons with Holm adjustment:

^xp<0.05, allopurinol vs. losartan;

^yp<0.05, allopurinol vs. placebo;

^zp<0.05, losartan vs. placebo