Table 1. Clinical characteristics of subjects (n = 324).
| Age, years | 57.9±13.0 |
| Male, n (%) | 176 (54.3) |
| Body mass index, kg/m2 | 24.4±4.7 |
| Diabetes mellitus, n (%) | 122 (37.7) |
| Hypertension, n (%) | 199 (61.4) |
| Dyslipidemia, n (%) | 183 (56.5) |
| Past CVD events, n (%) | 40 (12.3) |
| Medical treatments | |
| Ca antagonist, n (%) | 128 (39.5) |
| ACE or ARB, n (%) | 78 (24.1) |
| β or αβ blocker, n (%) | 35 (10.8) |
| Diuretics, n (%) | 15 (4.6) |
| Antiplatelet agent, n (%) | 33 (10.2) |
| Antidepressant agent, n (%) | 2 (0.6) |
| Current smoker, n (%) | 84 (25.9) |
| eGFR, ml/min/1.73 m2 | 86.8±19.9 |
| Albuminuria, n (%) | 40 (12.3) |
| AHI | 9.1±9.6 |
| Sleep duration, min | 379.6±95.5 |
| Sleep Efficiency, % | 90.3±7.3 |
| Movement index, % | 38.2±15.0 |
| Nocturnal SBP fall, % | 8.5±7.7 |
| ln (SDNN), msec | 4.78±0.28 |
| ln (SDANN5), msec | 4.66±0.31 |
| ln (BDNF), pg/ml | 7.7±0.8 |
Data are presented as the mean ± standard deviation or n (%) for dichotomous variables. HRV parameters (SDNN, SDANN5) and BDNF concentration were natural logarithm-transformed (ln) to achieve a normal distribution. Abbreviations: CVD, cardiovascular disease; ACE, angiotensin converting enzyme; ARB, angiotensin II receptor blocker; eGFR, estimated glomerular filtration rate; AHI, apnea hypopnea index; SBP, systolic blood pressure; SDNN, standard deviation of NN(RR) interval; SDANN5, standard deviation of average NN(RR) interval for each 5-min period; BDNF, brain-derived neurotrophic factor