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. 2020 Jul 17;10:11914. doi: 10.1038/s41598-020-68851-0

Table 1.

Demographic, clinical and polysomnographic characteristics of drug-free patients with restless legs syndrome (RLS) and controls.

Variable Controls
N = 73
Drug-free patients with RLS
N = 102
p value
n % n %
Demographic characteristics
Sex
 Male 28 38.36 39 38.24 0.99
 Female 45 61.64 63 61.76
Age, yearsa 56.85 (23.46; 76.65) 58.91 (24.50; 77.22) 0.20
BMI, kg/m2 23.41 (18.26; 34.53) 25.58 (18.34; 40.40) 0.001
BMI, kg/m2
 < 25 52 71.23 47 46.08 0.004
 25–30 19 26.03 44 43.14
 > 30 2 2.74 11 10.78
Clinical characteristics
Hypertension, Yes 10 13.70 16 15.84 0.70
Hypercholesterolemia, Yes 7 9.59 14 14.29 0.36
Diabetes mellitus, Yes 2 2.74 4 3.96 0.67
ESS total scorea 6.00 (0.00; 15.00) 10.50 (0.00; 23.00) < 0.0001
ESS total score, > 10 13 17.81 49 50.00 < 0.0001
ISI total scorea 5.00 (0.00; 19.00) 18.00 (4.00; 28.00) < 0.0001
ISI total score
 < 8 45 64.29 4 4.44 < 0.0001
 [8–15] 20 28.57 19 21.11
 ≥ 22 5 7.14 67 74.44
BDI II total scorea 5.00 (0.00; 25.00) 12.00 (1.00; 45.00) < 0.0001
BDI II total score
 ≤ 13 64 91.43 50 54.95 < 0.0001
 14–19 3 4.29 15 16.48
 20–63 3 4.29 26 28.57
Polysomnography measurements
Total sleep time, mina 364.00 (146.00; 525.00) 321.50 (53.00; 480.00) 0.0005
Sleep efficiency, %a 75.00 (28.37; 94.12) 71.25 (11.00; 6,300.00) 0.58
Wake time after sleep onset, mina 82.00 (17.00; 263.00) 102.00 (13.00; 404.00) 0.01
Sleep latency, mina 16.00 (0.00; 146.00) 16.50 (0.00; 300.00) 0.41
REM sleep latency, mina 93.00 (20.00; 207.00) 91.50 (12.00; 453.00) 0.22
N1, %a 6.48 (1.30; 35.79) 7.00 (1.88; 29.70) 0.31
N2, %a 54.79 (33.56; 74.68) 54.81 (30.69; 81.38) 0.64
N3, %a 20.27 (3.17; 42.12) 17.42 (0.00; 45.40) 0.11
REM sleep, %a 16.58 (2.04; 29.17) 20.13 (0.00; 43.21) 0.06
Microarousal index, /ha 14.00 (1.00; 46.00) 22.50 (0.00; 181.00) 0.0001
PLM during sleep index, /ha 1.15 (0.00; 71.06) 38.60 (0.00; 234.32) < 0.0001
PLM during sleep index, /h, ≥ 15 11 15.07 67 65.69 < 0.0001
PLM during wake index, /ha 7.56 (0.00; 108.29) 34.51 (0.00; 250.00) < 0.0001
Apnea–hypopnea index, /ha 3.77 (0.00; 40.81) 6.05 (0.00; 55.84) 0.16
Apnea–hypopnea index, /h ≥ 15 10 13.70 22 21.57 0.19
SaO2a 95.00 (91.00; 98.00) 95.00 (91.00; 98.00) 0.90

BMI body mass index (weight in kg divided by the square of the body height in meters), BDI Beck Depression Inventory, ESS Epworth Severity Scale, ISI Insomnia Severity Index, PLM periodic legs movements, REM rapid eye movement, SaO2 oxygen saturation.

aQuantitative variables are expressed as median (minimum value; maximum value).