Daytime QT by Routine 12-Lead ECG Is Prolonged in Patients with Severe Obstructive Sleep Apnea
Table 1
Baseline characteristics of the study population stratified by category of obstructive sleep apnea (OSA).
Variable
All (% or SD)
Normal-mild (% or SD)
Moderate (% or SD)
Severe (% or SD)
value
()
()
()
()
Age (years)
57.2 (12.5)
56.4 (13.4)
57 (11.8)
57.8 (12.4)
0.74
Sex (female)
125 (50.2%)
49 (68%)
35 (48.6%)
41 (39.1%)
0.0007
Race
White 194 (77.9%)
53 (73.6%)
64 (88.9%)
77 (73.3%)
Black 47 (18.8%)
17 (23.6%)
7 (9.7%)
23 (21.9%)
0.1
Other 8 (3.2%)
2 (2.8%)
1 (1.4%)
5 (4.8%)
Hypertension
182 (73.1%)
48 (66.7%)
48 (66.7%)
86 (89.9%)
0.03
HF
50 (20.1%)
13 (18.1%)
12 (16.7%)
25 (23.8%)
0.45
COPD
40 (16.1%)
20 (27.8%)
9 (12.5%)
11 (10.5%)
0.005
AF
43 (17.3%)
18 (25%)
7 (9.7%)
18 (17.1%)
0.052
BMI (kg/m2)
37.2 (9.4)
34.3 (8.7)
36 (8)
39.9 (10.1)
0.0002
AHI (/hr)
35.3 (29.7)
8.78 (3.79)
21.18 (4.3)
63.21 (25.93)
NA
Mean oxygen saturation (%)
92.7 (3)
93.6 (2.7)
93.2 (2.3)
91.6 (3.3)
<0.0001
On AV blockades
129 (52.2%)
34 (48.6%)
32 (44.4%)
63 (60%)
0.097
Values are means (SD) for continuous variables and percentages for dichotomous variables. Classification of apnea-hypopnea index (AHI): normal-mild: <15/hr, moderate: 15-30/hr, and severe: >30/hr. HF = heart failure; COPD = chronic obstructive pulmonary disease; AF = atrial fibrillation; BMI = body mass index; AV block = atrioventricular block; SD = standard deviation.
