Table 1.
Clinical, sleep questionnaire, transcranial Doppler, and white matter hyperintensity profiles of the study population.
| Age ≤ 50 years N = 25 |
Age > 50 years N = 25 |
P | |
|---|---|---|---|
| Clinical profiles | |||
| Age (year) | 36.1 ± 5.8 | 58.5 ± 5.5 | <0.001** |
| Male sex | 16 (64.0) | 21 (84.0) | 0.066 |
| Body mass index (kg/m2) | 23.1 ± 3.6 | 24.3 ± 2.9 | 0.192 |
| Hypertension | 2 (8.0) | 12 (48.0) | 0.001** |
| Diabetes mellitus | 0 (0.0) | 5 (20.0) | 0.022* |
| Hyperlipidemia | 0 (0.0) | 2 (8.0) | 0.162 |
| Use of ACEi/ARB | 1 (4.0) | 9 (36.0) | 0.005** |
| Use of calcium channel blocker | 0 (0.0) | 4 (16.0) | 0.043* |
| Smoking in past 5 years | 8 (32.0) | 13 (52.0) | 0.098 |
| Systolic blood pressure (mmHg) | 125.6 ± 13.0 | 129.5 ± 15.2 | 0.324 |
| Diastolic blood pressure (mmHg) | 74.5 ± 7.8 | 77.1 ± 9.0 | 0.275 |
| Mean blood pressure (mmHg) | 108.6 ± 9.9 | 112.1 ± 12.4 | 0.270 |
| Heart rate (no./min) | 72.0 ± 8.3 | 74.8 ± 10.7 | 0.294 |
| Sleep questionnaire profiles | |||
| Average sleep duration (hours)† | 6.4 ± 1.1 | 6.4 ± 1.4 | 0.885 |
| ESS score (0−24) | 3 (1.75–4) | 5 (4–10) | 0.007** |
| ESS score > 10 | 2 (7.7) | 5 (20.8) | 0.197 |
| High risk of OSA‡ | 9 (36.0) | 16 (64.0) | 0.023* |
| Waking TCD parameters | |||
| Evaluation time (sec) | 300.2 ± 67.8 | 298.6 ± 70.6 | 0.956 |
| MFV (cm/sec) | 68.2 ± 10.0 | 60.2 ± 11.8 | 0.012* |
| PI | 0.69 ± 0.11 | 0.78 ± 0.13 | 0.005** |
| MFV variation ([cm/sec]2) | 10.7 ± 14.4 | 7.8 ± 5.2 | 0.360 |
| Spectrum density analysis | |||
| ULF relative power (%) | 7.2 ± 4.4 | 7.1 ± 4.4 | 0.937 |
| VLF relative power (%) | 59.4 ± 16.6 | 65.0 ± 16.0 | 0.235 |
| LF relative power (%) | 32.8 ± 18.0 | 26.6 ± 16.7 | 0.215 |
| HF relative power (%) | 0.6 ± 0.7 | 1.3 ± 2.3 | 0.139 |
| Power of VLF peak frequency during sleep ([cm/sec]2) | 3246.4 ± 6192.9 | 2118.8 ± 1812.0 | 0.395 |
| Sleep TCD parameters | |||
| Evaluation time (sec) | 910.7 ± 300.6 | 840.8 ± 145.1 | 0.448 |
| MFV (cm/sec) | 69.7 ± 8.9 | 61.9 ± 11.2 | 0.009** |
| PI | 0.6 ± 0.1 | 0.7 ± 0.1 | <0.001** |
| MFV variation ([cm/sec]2) | 30.2 ± 12.9 | 27.2 ± 15.0 | 0.443 |
| Spectrum density analysis | |||
| ULF relative power (%) | 11.6 ± 4.1 | 9.6 ± 8.6 | 0.311 |
| VLF relative power (%) | 77.6 ± 6.2 | 81.8 ± 9.3 | 0.068 |
| LF relative power (%) | 10.8 ± 3.8 | 8.6 ± 5.4 | 0.104 |
| HF relative power (%) | 0.0 ± 0.1 | 0.0 ± 0.1 | 0.680 |
| Peak frequency of VLF band (Hz) | 0.013 ± 0.005 | 0.014 ± 0.005 | 0.305 |
| Power of VLF peak ([cm/sec]2) | 15433.8 ± 9759.4 | 18881.2 ± 14730.4 | 0.323 |
| Sleep/Waking Ratios | |||
| Mean MFV | 1.0 ± 0.1 | 1.0 ± 0.0 | 0.648 |
| Mean PI | 0.8 ± 0.2 | 0.9 ± 0. | 0.087 |
| MFV variation | 5.3 ± 5.8 | 5.1 ± 6.2 | 0.909 |
| VLF relative power | 1.2 ± 0.4 | 1.4 ± 0.7 | 0.274 |
| LF relative power | 0.4 ± 0.3 | 0.6 ± 0.5 | 0.111 |
| HF relative power | 0.0 ± 0.1 | 0.1 ± 0.4 | 0.194 |
| Relative power of VLF peak | 3.1 ± 3.7 | 2.7 ± 1.8 | 0.617 |
| WMH volume parameters | |||
| Total WMH (mL) | — | 2.8 ± 2.3 | — |
| Subcortical WMH (mL) | — | 1.3 ± 1.1 | — |
| Periventricular WMH (mL) | — | 1.6 ± 1.7 | — |
Data are reported as a number (percentage), mean ± standard deviation, or median (interquartile range, IQR). ACEi/ARB, angiotensin converting enzyme inhibitor/angiotensin receptor blocker, ESS, Epworth sleepiness scale, OSA, obstructive sleep apnea, MFV, mean flow velocity, PI, pulsatility index, ULF, ultra-low frequency band, VLF, very low frequency band, LF, low frequency band, HF, high frequency band, and WMH white matter hyperintensity. †Average sleep duration of the last 3 nights prior to the evaluation, ‡Determined per the criteria of the Berlin questionnaire, *P < 0.05, **P < 0.01.